# Seat tube angles are too steep and chain stays are too short.



## alexbn921 (Mar 31, 2009)

A tall man's perspective on current geometry trends for mid travel trail/enduro bikes.

STA are far too steep on the current crop of bikes. 76+ degrees is the norm and it's a bad trend. This places your knees too far forward over the pedal and reduces your power. Now here's the biggest kicker with the slid forward position, hand pressure. Having your hips further back creates a force vector up and back during your pedal stroke that takes the weight off your hands. It is one form of fitting metric on road bikes, can you lift your hands off the bars while pedaling without increasing your cadence. This balance point helps keeps you comfortable on the bike for longer rides. The logic behind steep STA is that they help climbing and since everyone is running a long dropper, we can get away with them and this is true. Manufactures have gone too far, compromising the rest of bike fit for this one metric.

This is combined with the shortest possible chain stay length. Short CSL gives you a snappy bike that combats the super long front center. In the small and medium sizes CSL to front center ratio is still an acceptable ratio. In the larger sizes balance is severely compromised by this front to rear ratio. The longer the front, the more you reduce pressure on the front tire. Since STA has no bearing while descending and reach has grown, riders fit short stems, further reducing front end grip. Most riders also like a higher handlebar height reducing front end grip even more. To compensate for the reduced front-end grip, you need to ride forward putting more pressure on your hands.

Larger bike NEED longer stays! This helps climbing traction, puts weight on the front wheel without hand pressure and lets you run high handlebars, further reducing hand pressure.

Seat tube angles should be slacker for less travel and 74-75 is a much better compromise than 76+. Less travel = less weight shifted rear sag and STA change while climbing. With longer stays you don't need to have the extreme STA for climbing performance.

Reach has settled into about the perfect range and longer just for longer is not really need.

HTA is about perfect too. This too seems to be approaching the point on endure bikes where bushing bind starts to limit fork action.
Short offset forks are great. They reduce front center (something we desperately need) and I prefer the feel of them.

Stems are too short. This reduces front end weight and is used to speed up the extra wide bars and super slow steering geometry. 50mm is the sweet spot. Short travel bikes should be longer.

Handlebars are too wide. 800mm+ is too wide and compromises body position during cornering and does not place rides in their strongest position during descending. I like the push up method for bar width.

Great deep dive video on the subject.


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## 93EXCivic (Mar 12, 2018)




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## alexbn921 (Mar 31, 2009)




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## mack_turtle (Jan 6, 2009)

If the STA on a bike is too steep for YOUR PERSONAL PREFERENCE, you can buy something else.

If a frame has chainstays that are too short for YOUR PERSONAL PREFERENCE, you can buy something else. Many modern hardtails have adjustable dropouts so your can stretch your bike out to handle like a school bus.

If handlebars are too wide for YOUR PERSONAL PREFERENCE, no one can stop you from taking a hacksaw to them. In fact, I am certain that most manufacturers make handlebars extra wide, and go to the trouble to put width markings on their product with the assumption that most customers are going to cut them down. That's what I do- buy a 810mm bar and immediately cut it down to 760-770.

The "push up method" for measuring handlebar width is 100% bullshit. It tells you where to put your hands to do a push-up, nothing more. KOPS is also bullshit. That's old news.


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## rebel1916 (Sep 16, 2006)

Modern bikes descend insanely well, while climbing almost as well as those old school hardtails we grew up on. And I ride an L.


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## Sparticus (Dec 28, 1999)

To each their own — ride whatever serves you best.

I had my first custom mountain bike frame built in ‘94 and it included a 76° STA — I was hooked. I’m in process of having another custom HT built right now and it’ll sport a 78-79° STA. Crazy? Maybe for somebody else, not for me. I’m 6’2”.

Personally I love a steep seat tube angle but I see posts within these forums all the time made by people who hate them. I think individual body dimensions, riding styles & personal preferences come into play here. I don’t believe there’s a universal “right” or a “wrong,” rather there’s whatever serves the individual rider best.
=sParty


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## 06HokieMTB (Apr 25, 2011)

Aren't steep STA's even more important for tall guys with long legs?


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## jcd46 (Jul 25, 2012)

Why are people so hang up on numbers? I go from one bike to another and don't give it a second thought after a few seconds of adjusting.

Pedal and have fun.


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## Shayne (Jan 14, 2004)

Not a fan of the steep seat tube either.
I already had to run my saddle all the way back with 73* seat angles.


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## mack_turtle (Jan 6, 2009)

jcd46 said:


> Why are people so hang up on numbers?


Because it gives us the illusion of scientific objectivity when we want to be pedantic chuckleheads about our personal preferences!


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## Forest Rider (Oct 29, 2018)

Move your seat back (if you haven't already).
That changes the seat tube angle (effectively).


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## milehi (Nov 2, 1997)

I agree. The trend will run it's course when SAs are 90* and HAs are 50*. Bars will be 1000mm wide. The industry jumped the shark a couple years ago but the lemmings will buy what they're told to buy. The industry is desperate for a sale. Big slow wheels, obnoxious geo, downcountry(WTF?) Mullet bikes. Anything to make a buck off what's old is new again. Thank God for small custom builders.

Have fun on those goofy chopper bikes, thinking it's the latest and greatest.


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## Sparticus (Dec 28, 1999)

Vader said:


> I agree. The trend will run it's course when SAs are 90* and HAs are 50*. Bars will be 1000mm wide. The industry jumped the shark a couple years ago but the lemmings will buy what they're told to buy. The industry is desperate for a sale. Big slow wheels, obnoxious geo, downcountry(WTF?) Mullet bikes. Anything to make a buck off what's old is new again. Thank God for small custom builders.
> Have fun on those goofy chopper bikes, thinking it's the latest and greatest.


Hey Vader, through reading your posts over the years I know you're an accomplished rider. May I ask what frame(s) you're riding these days? Thanks.
=sParty


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## alexbn921 (Mar 31, 2009)

06HokieMTB said:


> Aren't steep STA's even more important for tall guys with long legs?


Yes it is. We need to make sure that our CG is not behind the rear axle while climbing. Super short rear stays decrease the room we have to move back. Older bikes with super slack virtual STA put most people too far back, but tall guys especially. All my seats where as far forward as possible. Now we've go to the other extreme and and my seat is all the way back.



Forest Rider said:


> Move your seat back (if you haven't already).
> That changes the seat tube angle (effectively).


Seat is all the way back and is a style that naturally sits further back too. I understand that there is personal preference and variable fit for different body types. The first thing I tell people on new bikes when they say they feel small is slide your seat back all the way.

There has to be a sweet spot. I don't believe it's 76-77 deg. That sweet spot is 74-75 in my opinion and seems to fit the majority of riders I ride with.

It seems STA get steeper every generation of bikes.


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## milehi (Nov 2, 1997)

Sparticus said:


> Hey Vader, through reading your posts over the years I know you're an accomplished rider. May I ask what frame(s) you're riding these days? Thanks.
> =sParty


I'm on a custom six inch Ventana. I went custom because nobody was making long low and slack geo ten years ago. The frame before that was the same but it was destroyed in a head on with a dirt bike. The geo is nothing crazy these days. 74SA 67HA 24"TT and 13"BB on an 18 inch frame.

I'm about to order a Guerilla Gravity Megatrail.

I also ride a custom steel SS. That geo is 73SA 68HA and 24"TT

The other day I was watching a drone video of a new choppered out 29er on twisty singletrack. The guy had to slow to a crawl to make each turn. It didn't look fun.


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## Sparticus (Dec 28, 1999)

Vader said:


> I'm on a custom six inch Ventana. I went custom because nobody was making long low and slack geo ten years ago. The frame before that was the same but it was destroyed in a head on with a dirt bike. The geo is nothing crazy these days. 74SA 67HA 24"TT and 13"BB on an 18 inch frame.
> 
> I'm about to order a Guerilla Gravity Megatrail.
> 
> ...


Congrats on your decision to get a Guerrilla Gravity bike. That's the brand of my FS bike I ride as well, tho my frame is one of their final generation aluminum models (Aug. '18). The new CF frames look terrific.
=sParty


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## milehi (Nov 2, 1997)

Sparticus said:


> Congrats on your decision to get a Guerrilla Gravity bike. That's the brand of my FS bike I ride as well, tho my frame is one of their final generation aluminum models (Aug. '18). The new CF frames look terrific.
> =sParty


They have a small hand full of aluminum frames left which is what I'm after.


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## jeremy3220 (Jul 5, 2017)

I'm 6'5" and love the steep seat tubes. I don't like short chainstays for enduro/DH but they're great at keeping the wheelbase in check on tight terrain. They also make little difference in climbing (I have a bike with 419mm chainstays and one with 446mm stays). I think if there's too much pressure on your hands then your bike might be a bit small (bars too far under you).


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## str8edgMTBMXer (Apr 15, 2015)

jcd46 said:


> Why are people so hang up on numbers? I go from one bike to another and don't give it a second thought after a few seconds of adjusting.
> 
> Pedal and have fun.


same here...I mean, I get what the geo does for riding, but I always just adjusted as well


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## Blatant (Apr 13, 2005)

Hey, man, despite all the naysayers (most of whom probably aren't, you know, man-size), I mostly agree with your original post.

I do like my 820 bars, but I have super-wide shoulders and stupid-long arms. 

I think chain stays are too short on larger frame sizes. I remember a few years back when the race was to the shortest stays and that was the only real metric. Today, it's crazy reach and steep seat angles.

I think it's mostly for the better and probably as close to perfect as it's ever been, though.


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## knutso (Oct 8, 2008)

A steep SA allows for a shorter chainstay, they go hand and hand. You can only have so many things going on between chainrings, derailleurs, tires, suspension and (possibly bent) seattubes. There just is not enough room to go around. Needless to say, derailleurs and chainrings got the ax. Now a steeper SA is openning up more freedom in suspension design, along with shorter stays and bigger tires. 

My honest opinion is it is more about clearing space around the BB than it is about ergonomics. More suspension, bigger tires and shorter stays sells bikes for a premium.


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## milehi (Nov 2, 1997)

Blatant said:


> Hey, man, despite all the naysayers (most of whom probably aren't, you know, man-size), I mostly agree with your original post.
> 
> I do like my 820 bars, but I have super-wide shoulders and stupid-long arms.
> 
> ...


Do we really need super short chainstays? The idea behind them has always been about climbing, but now we have rediculous pizza pan sized cogs for that. And who cares about climbing since we soft pedal to the next timed section of a smooth flow trail (thanks soft generation) I'd like more stability for blistering speeds. These days, all bikes look the same. Boring. There's nothing exciting going on.

I'm a standard size man at 6' with a neutral ape index since you're keeping score.


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## Outhouse (Jul 26, 2019)

6' 200lbs, I have no issue at all, and my seat is not all the way back. I set my bike up with seat alignment set for proper knee tip position over center peddles. To far back and you will screw up cadence. I have no complaints.


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## 93EXCivic (Mar 12, 2018)

I like short chain stays. I mean it isn't the only part of the equation but IMO it helps make a bike feel more fun and I am more then willing to give up a bit of climbing performance for that.


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## Miker J (Nov 4, 2003)

Can't get something for nothing. There are trade offs. Steeper STA, to me, seem to rob my horsepower. Shifts pedal power to the relative weaker quads, away from the stronger hammies. 

But since mtb tech/design is still young there are improvements to be made. For shorter travel bikes maybe a STA about 75 might be a happy medium. Problem is every one thinks they need to buy more travel instead of learning more skill. Longer rear travel sags too much on the steeps.


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## Suns_PSD (Dec 13, 2013)

Some points the OP made I agree with, and some I don't. But the really cool thing about modern bikes is we have so many choices, even 100% custom high end options. So what's the problem?
I do think seat post angles are getting a bit extreme but I do really like my own 75.5' STA. 
Chainstays need to fit the size of the bike and this was really a factor for me when I purchased a size small bike for my wife. But being average sized man riding a large I feel like the CS lengths are pretty much designed around this size bike so stock sizes work well for me.
BBs are just too darn low for chunk, not to mention cranks too long. But I guess bikes are designed on much smoother trails than what I ride.


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## Shayne (Jan 14, 2004)

suns_psd said:


> but the really cool thing about modern bikes is we have _[the illusion of]_ so many choices, .


fify


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## str8edgMTBMXer (Apr 15, 2015)

93EXCivic said:


> I like short chain stays. I mean it isn't the only part of the equation but IMO it helps make a bike feel more fun and I am more then willing to give up a bit of climbing performance for that.


I was thinking the same thing...and wonder if that comes from our BMX "heritage"...


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## alexbn921 (Mar 31, 2009)

93EXCivic said:


> I like short chain stays. I mean it isn't the only part of the equation but IMO it helps make a bike feel more fun and I am more then willing to give up a bit of climbing performance for that.


I still have an XL 2007 Blur XC carbon that has some of the shortest possible CS on a 26er. I love the feel and snap of them and since the bike has less front center then a current medium bike now the balance is very good. I can't climb anything steep on it though as after 20% grade I'm behind the rear axle and if I shift my seat more forward I would need a crazy long stem.

The Santa cruz tallboy 3 used the same rear end with different front ends that where 100mm longer. Something's gotta give over that big of a change.



Miker J said:


> Can't get something for nothing. There are trade offs. Steeper STA, to me, seem to rob my horsepower. Shifts pedal power to the relative weaker quads, away from the stronger hammies.
> 
> But since mtb tech/design is still young there are improvements to be made. For shorter travel bikes maybe a STA about 75 might be a happy medium. Problem is every one thinks they need to buy more travel instead of learning more skill. Longer rear travel sags too much on the steeps.


Exactly. Steep STA are great for climbing but negatively affect your power output. They are combined with long reach(super happy about this, as bikes actually fit me now) and Chain stays that are shooting for the shortest possible without looking at bike balance.

75 seems like a very good compromise for range of adjustment. I really like what Santa Cruz is doing with their adjustable rear flip chips. It's smart and cost effective.


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## mack_turtle (Jan 6, 2009)

You guys realize that saddles can be moved fore and aft to your liking, regardless of STA, right? I did the math:
If you're my hieght, a total saddle height of 75cm has an offset of about 220mm at 73°. At 76°, the offset is 180mm. That's a difference of 40mm. I tried it with a few other saddle heights and the difference between a 73 and 76° STA averages 30-40mm.

Most saddles and seatposts allow at least 10mm of adjustment and many seatposts have, what, 16mm of layback offset? In other words, you can get the vertical offset on your saddle within a few mm of your old bike if you're going from an old school slack STA to a nu school steep one.

If you can feel that particular pea when you ride, you're a very special princess indeed. However, I am going to join the chorus of people who have been saying for many years that saddle fore-aft is not that important. You may think it's important because, at some point, you or someone you trust dropped a string from an arbitrary point on your knee and told you that was the optimal position for you to pedal because it makes your knee line up with your pedal because gravity and stuff. Horse puckey!


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## alexbn921 (Mar 31, 2009)

mack_turtle said:


> You guys realize that saddles can be moved fore and aft to your liking, regardless of STA, right? I did the math:
> If you're my hieght, a total saddle height of 75cm has an offset of about 220mm at 73°. At 76°, the offset is 180mm. That's a difference of 40mm. I tried it with a few other saddle heights and the difference between a 73 and 76° STA averages 30-40mm.
> 
> Most saddles and seatposts allow at least 10mm of adjustment and many seatposts have, what, 16mm of layback offset? In other words, you can get the vertical offset on your saddle within a few mm of your old bike if you're going from an old school slack STA to a nu school steep one.
> ...


Of course seats can be be moved around. it's a very good fitting tool. If most of the seats on a 76 STA bikes are all the way back that says something to people's preferences.

I have several bikes all with different STA and tend to feel the differences when switching. There is no perfect singular setup, but have STA gone to far in one direction?

FYI I don't subscribe to the the knee directly over the pedal and cleat position also plays a roll.


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## jeremy3220 (Jul 5, 2017)

mack_turtle said:


> You guys realize that saddles can be moved fore and aft to your liking, regardless of STA, right?


No, on a 73° STA the saddle cannot be moved to my liking. On my Hightower LT I ran the saddle as far forward as it would physically go in the clamp and still felt like I was hanging off the back of the bike. Now on a bike with a 76° STA and I still run the saddle pretty far forward. 30-40mm is a big difference in bike fit as we all know.


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## mack_turtle (Jan 6, 2009)

jeremy3220 said:


> No, on a 73° STA the saddle cannot be moved to my liking. On my Hightower LT I ran the saddle as far forward as it would physically go in the clamp and still felt like I was hanging off the back of the bike. Now on a bike with a 76° STA and I still run the saddle pretty far forward. 30-40mm is a big difference in bike fit as we all know.


Agreed, sometimes a STA is just too steep or slack for one's liking, which means that bike is not for you.

However, when I stated the 30-40mm figure, that's the absolute, fixed position. When you consider how adjustable the saddle position is, you should be able to get it much closer than that. That might not be enough, which means the bike just doesn't fit you very well.

My point is that the difference between a few degrees in STA is not not set in stone. 99% of the people who pick a frame that was (well) designed with their dimensions and riding style in mind can make it fit without compromising handling. If not, it was not designed with that rider's body proportions or riding style in mind.

How much of an epidemic is the ultra-whatever bike dimensions phenomenon anyways? Did every bike company in the world start building bikes with 90° seat tube angles, 45° head tubes, and bottom brackets that barely clear the tarmac overnight, or are some of us bored and being just a bit hyperbolic?


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## Forest Rider (Oct 29, 2018)

My two bikes probably have different knee over pedal positions. I don't know, didn't measure it. I can tell there is a difference though in how my power delivery is, like one feels like power on the down stroke more than another what seems to be powerful a little sooner in the rotation.

Plus I ride flat pedals and I move my feet around. I don't know if my knee over pedal position is the same for 10 minutes straight, never mind assume that that position must be solid from now to eternity.

I'm sure that feeling matters to some people that are more fine-tuned. For me though, I just ride and have fun and make the best at what I'm given. 
I like my saddle height to be optimal. I like the tilt to feel good. Not want either to change. My bar height is pretty finicky but not 100%. My bars are different widths an stems are different length. Whatever, they both work for me.
I've had to move my seat forward as far as possible to adjust for the longer reach of one bike so my seat tube is probably even more steep than it should be.
I compensate for that by not caring about position of my boy vs. crank.
I don't race so I don't have to be in the optimal position for 3 hours non-stop. I'm blessed with a body that doesn't ache when some bike changes of 1mm occur. 

I get that some people are not so blessed though.

But I think Mack nailed it above, we believe what we want to. A person could have learned that "this is optimal" and are afraid to deviate because the numbers don't work but determined without actually trying to adapt. 

This is one of those things that will keep the internet in a debate though. Just like flat/clips, narrow/wide bars, 12 speed or other.
Hooray


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## EatsDirt (Jan 20, 2014)

mack_turtle said:


> However, I am going to join the chorus of people who have been saying for many years that saddle fore-aft is not that important. You may think it's important because, at some point, you or someone you trust dropped a string from an arbitrary point on your knee and told you that was the optimal position for you to pedal because it makes your knee line up with your pedal because gravity and stuff. Horse puckey!


I've been saying for many years that saddle fore-aft/STA is a deal breaker for me, and I know I am not alone. I know what feels right (for me) and no plumb bob is needed.

A chorus of people who don't know any better, don't feel the difference, or don't care is just the sound of farts in the wind.


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## Mudguard (Apr 14, 2009)

alexbn921 said:


> I can't climb anything steep on it though as after 20% grade I'm behind the rear axle and if I shift my seat more forward I would need a crazy long stem.


I don't know if I've ever ridden a 20% gradient, seated, standing or if ever!
NB. I've no idea what my seat angle is. All I know is on my old Big Hit and SX it was very slack. Wheelie city.



Not level ground and over-forked





Made steeper by the 26" rear wheel kit


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## aerius (Nov 20, 2010)

mack_turtle said:


> How much of an epidemic is the ultra-whatever bike dimensions phenomenon anyways? Did every bike company in the world start building bikes with 90° seat tube angles, 45° head tubes, and bottom brackets that barely clear the tarmac overnight, or are some of us bored and being just a bit hyperbolic?


Looked at 2020 geometry charts lately? It's gone past the epidemic stage and is well on the way to being a pandemic. Other than Giant, all the other big manufacturers are on stupid steep & slack trend, and most of the smaller companies are as well. Once everyone catches up on their product cycles in another 1-2 years it's gonna be even worse.


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## Miker J (Nov 4, 2003)

How about this...

One could argue the motor is the weakest link when it comes to mtb performance. So anything that effects that with regard to bike fit needs to be considered in frame design. (not saying this one parameter is the end all be all, but it is important.)

When it comes to generating pedal power what is considered "optimal" STA? When the big bucks are to be had at the pro-level I'd say maybe we should look at where is the most R&D with regard to what STA allows a rider to generate the most horse power.

Can we then extrapolate STA's from pro road bikes to mtb? I'd bet that if a STA of 76 allowed the best power output we'd see more road bikes with that STA. Is that the case? Really, I don't know . Maybe some silly UCI rule dictates what the STA has to be.

Yeah, I know that mountain biking is a different animal, but there are similarities - enough similarities to not just disregard the point.

There will likely be a happy medium when it comes to pedal power vs bike handling. Again, the less the rear travel sags the less a potentially power robbing steep STA is needed.

Not sure if my lines of thinking are correct at all but thought I'd throw it out there to see what others think.


Again, not against steep STAs, but there is likely going to be a sweet spot for any bike's given travel. Maybe the adjustable geo thing is where its at.


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## Suns_PSD (Dec 13, 2013)

I use to have a link to a college study done where power output was measured at different seat angles. Steeper was better with significant power improvements as they went steeper but the steepest they tested as I recall was around 75.
However keep in mind that when an Enduro bike sags, it gives up a considerable amount of that seat tube angle. 
So 77 degrees on an Enduro 29 might be equal to a 73 on a HT for instance. 

Sent from my SM-G892A using Tapatalk


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## jeremy3220 (Jul 5, 2017)

Suns_PSD said:


> I use to have a link to a college study done where power output was measured at different seat angles. Steeper was better with significant power improvements as they went steeper but the steepest they tested as I recall was around 75.
> However keep in mind that when an Enduro bike sags, it gives up a considerable amount of that seat tube angle.
> So 77 degrees on an Enduro 29 might be equal to a 73 on a HT for instance.
> 
> Sent from my SM-G892A using Tapatalk


Yep, climbing on a long travel bike with a 'steep' STA doesn't feel that steep and my knees aren't out in front of my pedal spindles. Everyone keeps forgetting that riding is dynamic. That KOPS measurement you took in your garage goes out the window once you start riding different grades and different sag amounts. My hardtail with a 74° effective/75° actual STA feels like it has a steeper STA than my enduro bike with a 76° STA on the climbs.


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## Battery (May 7, 2016)

My Recluse has a 419mm chainstay, 75 degree seat tube angle, and it's a large. Hell if I care. It's just fun to ride   

The rear end is snappy and I climb way better now. I almost get an erection just thinking about the next ride on my Recluse.


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## *OneSpeed* (Oct 18, 2013)

alexbn921 said:


> A tall man's perspective on current geometry trends for mid travel trail/enduro bikes.
> 
> STA are far too steep on the current crop of bikes. 76+ degrees is the norm and it's a bad trend. This places your knees too far forward over the pedal and reduces your power. Now here's the biggest kicker with the slid forward position, hand pressure. Having your hips further back creates a force vector up and back during your pedal stroke that takes the weight off your hands. It is one form of fitting metric on road bikes, can you lift your hands off the bars while pedaling without increasing your cadence. This balance point helps keeps you comfortable on the bike for longer rides. The logic behind steep STA is that they help climbing and since everyone is running a long dropper, we can get away with them and this is true. Manufactures have gone too far, compromising the rest of bike fit for this one metric.
> 
> ...


Wow, what a wonderful example of someone who either hasn't spent a fair amount of time on "modern geometry" trail bikes, OR just doesn't understand bike geometry.

This sounds like arm chair quarterback complaining instead of real world experience talking.

6'3" here, never met a chainstay that was too short. Recent mid-travel trail bike purchase is arguably the most fun and capable bike I've ever ridden. 427mm chainstays, 76.2 STA and the saddle is all the way forward. 800mm bars, corners like it's on rails thanks in no small part to my 210mm dropper.

Don't like the bike you're riding? Try something else. Some brands DO lengthen the chainstays based on the size, but I wouldn't buy one for my local terrain. I've also spent a fair amount of time on a hardtail with 415mm chainstays, NOT too short.

If you want to make terrible statements that highlight your poor understanding of bike geometry, you could at least be specific about what bike you're talking about so we can analyze your impression of what's "bad" about the geometry you don't like.

If you prefer 455mm chainstays, slack seattube angles, and 71 degree HTA with 120mm stem because it allows you to "properly" weight the front wheel... There's a 99 Trek on eBay with your name on it.

Modern geo rocks, though it doesn't seem you understand it well or have found the right combination to suite your personal preferences.

Edit: minor typo, see below


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## Blatant (Apr 13, 2005)

Overreact much? ^^^^^


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## Shayne (Jan 14, 2004)

*OneSpeed* said:


> 327mm chainstays,


24" Wheels?!?


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## 93EXCivic (Mar 12, 2018)

*OneSpeed* said:


> 327mm chainstays


Those are some short chainstays.


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## *OneSpeed* (Oct 18, 2013)

Shayne said:


> 24" Wheels?!?





93EXCivic said:


> Those are some short chainstays.


Actually yes, it's a folding bike with 18" wheels.  Killer offroad bike. 

Speaking of which, when will we see a progressive geo folding bike? Seems overdue. :skep:


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## alexbn921 (Mar 31, 2009)

Miker J said:


> How about this...
> 
> One could argue the motor is the weakest link when it comes to mtb performance. So anything that effects that with regard to bike fit needs to be considered in frame design. (not saying this one parameter is the end all be all, but it is important.)
> 
> ...


This is exactly my thinking on the subject. It's going to be a compromise, but it seems that right now, more is better is all that is talked about.

Look at me! We made this bike more extreme! Some of it's better and some of it is worse. The overall package of bikes today is better, but I believe we have gone a little to far with some measurements.


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## alexbn921 (Mar 31, 2009)

*OneSpeed* said:


> Wow, what a wonderful example of someone who either hasn't spent a fair amount of time on "modern geometry" trail bikes, OR just doesn't understand bike geometry.
> 
> This sounds like arm chair quarterback complaining instead of real world experience talking.
> 
> ...


Wow is right.
I have lots of experience on all bikes for the last 30 years. In the last 10 years I have had the pleasure of riding over 20 mountain bikes from friends and demos. This includes all of the linkage forks and structure linkage bike. I have also been on 10+ road bikes.

As of right now I have in my garage:

1997 XL Super V with a 170mm stem. Ubered out with period correct XTR, mavic crossmax wheels and Next carbon exoskeleton cranks. It has a rack, trailbike and burley attachments on it. I ride it all over town.

2007 XL Blur XC Carbon with a 90mm. XX1 11 speed with XTR brakes. 22.5lb in XC race setup. Still race this bike with a 27.5 enve wheel conversion. It's way too small for me, but was one of the longest bike at the time.

2018 XL Ripmo with a 60mm stem. 200mm dropper. XX1 12 speed with XTR brakes. Front is upgrade to 4 piston. I love this bike and consider it the best trail bike ever made.

I just built up a Roubaix road bike and like every bike listed it was built from the frame up with every single part picked by me for its intended purpose.

Tuning suspension and building race cars was my background in collage and now I'm an electrical engineer. I like to geek out on this stuff, trying to find the why it works and how to make it better.

It doesn't seem like you really care about it that much but still took the time to attack my motive and not offer any useful information. You missed my point and no I don't want a 99 trek off ebay.

Someone at these companies has to make the decision on what is the best setup for the next generation of bikes and we as a community of enthusiasts should have some input. I know that a lot of manufactures are present on these forms.


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## Suns_PSD (Dec 13, 2013)

https://www.ncbi.nlm.nih.gov/pubmed/9293416

Effect of variation in seat tube angle at different seat heights on submaximal cycling performance in man.

Abstract

The effect of seat tube angle at selected seat heights (96, 100 and 104% trochanteric height) on heart rate, VO2 and lower limb kinematics was evaluated in 14 competitive male road racing cyclists during discontinuous submaximal exercise (200 W) on an air-resistance ergometer at seat tube angles of 68, 74 and 80 degrees. The tests were randomized to complete the nine combinations (three seat heights, three tube angles) in opposite directions from a starting tube angle of 74 degrees and 100% trochanteric height to avoid any time or sequence bias. Power efficiency was calculated for each combination from work done and VO2. All results were analysed using ANOVA for repeated measures. At a seat tube angle of 80 degrees, mean VO2 was significantly lower and power efficiency significantly higher compared with an angle of 74 degrees at all three seat heights, while heart rate was significantly lower only at a seat height equal to trochanteric height. At a seat tube angle of 74 degrees, mean VO2 and heart rate were significantly lower and power efficiency significantly higher compared with an angle of 68 degrees at all three seat heights. Hip range of movement and maximum and minimum hip angle were significantly less at an angle of 80 degrees compared with 68 degrees. Further biomechanical analysis suggested that the improvement in cycling efficiency observed at steeper seat tube angles was produced in part by the resultant altered ankling pattern of the cyclist.


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## mack_turtle (Jan 6, 2009)

Mountain bikers don't sit on stationary road bikes. I see the potential for a parallel there, but I think it leaves a lot out.


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## scottzg (Sep 27, 2006)

555


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## Miker J (Nov 4, 2003)

Hmmm. Interesting.


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## alexbn921 (Mar 31, 2009)

https://pdfs.semanticscholar.org/1448/729fb2205000133847c1cebca44a5e4121dd.pdf

DISCUSSION: The total amount of work of right leg during a rotation of crank was the lowest
between 78 and 68 degree of seat tube angle. So we can conclude that cycling at 72 degree
of seat tube angle is most work efficiency because work cost of a lower limb muscle was the
lowest where 250 Joule of work output at crank was achieved identically. It is same result to
previous study that low seat tube angle between 72~76 degree is more preferable when road
racing cycling (Heil et al., 1995). Work efficiency (74.7%) during transmission from muscle to
crank can be deduced from equation described as flowing:

CONCLUSION: In this study the effect of seat tube angle on the cycling performance was
investigated in terms of net muscle works using human model simulation. A comparison
between the net muscle works of lower limb muscle and the works achieved from crank
during a crank revolution was made. In conclusion, at around 72 degree of seat tube angle is
most efficiency at lower limb kinematics point of view.

I believe that STA is variable between different styles of bikes. IE time trial bikes require a much steeper STA because of the forward leaned over position.

I seem to like around 72 on my road bike and and am willing to go steeper on a mountain bike as the benefit of climbing performance is worth it to me. Longer stays would compensate the climbing performance and allow a more ideal STA. They would also balance out the front ends extra length. 74-75 = 72-73 while climbing with sag account for.


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## d365 (Jun 13, 2006)

I've been riding for a few decades, always on L frames. I prefer 17" CS, and 75-76º SA. YMMV


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## mack_turtle (Jan 6, 2009)

Well my bike has a 71.5° STA so I am super efficient, now that I know science proves it! Therefore, I am faster, more aggressive, and have more fun flicking and smashing and getting radnthan any of you.


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## Suns_PSD (Dec 13, 2013)

alexbn921 said:


> https://pdfs.semanticscholar.org/1448/729fb2205000133847c1cebca44a5e4121dd.pdf
> 
> DISCUSSION: The total amount of work of right leg during a rotation of crank was the lowest
> between 78 and 68 degree of seat tube angle. So we can conclude that cycling at 72 degree
> ...


What a funny (as in ****) research study!

I like how they concluded that somewhere between 68 - 78 degrees, so they just split the difference with differentiation. For all we know they tested at an actual 78 degrees and got the best results.


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## alexbn921 (Mar 31, 2009)

They have a chart and breakdown of individual muscles doing the work. Just an example. Don't really have any skin in the game to validate the results.


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## mack_turtle (Jan 6, 2009)

These tests are done on stationary road bikes with the riders sitting and spinning. What does that tell us about riding a mountain bike on technical terrain with constantly changing grades? Not a whole lot, I suspect.


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## durkind (Jul 8, 2005)

aerius said:


> Looked at 2020 geometry charts lately? It's gone past the epidemic stage and is well on the way to being a pandemic. Other than Giant, all the other big manufacturers are on stupid steep & slack trend, and most of the smaller companies are as well. Once everyone catches up on their product cycles in another 1-2 years it's gonna be even worse.


Specialized Stumpjumper is 74 degrees
Trek Fuel EX is 75 degrees
Last I checked these are some big manufactueres


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## Forest Rider (Oct 29, 2018)

Is the larger the number the steeper the angle? Assume angle is measured clockwise based on a origin of the 9:00 position, towards 12:00?


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## alexbn921 (Mar 31, 2009)

durkind said:


> Specialized Stumpjumper is 74 degrees
> Trek Fuel EX is 75 degrees
> Last I checked these are some big manufactueres


Specialized 2020 kenevo is 77 STA.


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## PuddleDuck (Feb 14, 2004)

Humans bodies aren't identical. Some peeps need steeper seat tubes because of their anatomy, some need slacker seat tubes. From my perspective angles are too steep, but I can understand, AND I can accept, that others need steeper angles. 

Here's an anatomical truth in a post truth world. Those with longer femurs need slacker STA's to balance the work done by the quads vs hammies & glutes. The opposite is true for those with shorter femurs. 



What's played out on this thread is is a sad and funny situation at the same time. 

It's the same as the argument regarding gearing range. Those who can push numerically low gears e.g. big chainrings in a 1x set up, berate those asking for a 30T or 28T or 26T ring...and say stuff like "get get fitter", or, "just ride more". Some people are spinners not grinders, or don't have the time to ride more, or ride at high altitudes, or are genetically challenged. It's sad and hilarious that the "just get fitter" types can't or won't understand and accept other peoples reality. I see the same thing on this thread. 

For those in the USA: Given the political challenges that those in the USA, the divisiveness and polarisation...I'm wondering if this intolerance and unwillingness to "stand in someone else's shoes" that we have in MTBR is:
(1) a by-product of the current political environment, 
(2) a driver and cause of the current current political environment?


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## jeremy3220 (Jul 5, 2017)

Forest Rider said:


> Is the larger the number the steeper the angle? Assume angle is measured clockwise based on a origin of the 9:00 position, towards 12:00?


Yes


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## *OneSpeed* (Oct 18, 2013)

Let's try this again. You've done a poor job of explaining your gripe and haven't given any specific references. You also contradict yourself.

You write your OP as fact. You're not offering your opinion, you're making statements as though they are fact. You are not asking if it's the best for every bike, or what others think, just boldly stating that it's wrong somehow.



alexbn921 said:


> This places your knees too far forward over the pedal and reduces your power. Manufactures have gone too far, compromising the rest of bike fit for this one metric.


How so? Seems most people really like the new bikes, geometry included. Most brands are following these trends and it's done great things for the handling of 29ers in particular. Early days were no bueno for 29ers.



> This is combined with the shortest possible chain stay length.


Often, Yes. *It's a package deal.* Short chainstays, steeper STA, lower BB, longer front center, much longer Reach, much shorter Stem. When executed properly it's magical.

What you seem to fail to recognize is that the "fit" of modern bikes isn't all that different than older bikes. *A large is still a large.* The distance between your saddle and the handlebar is likely very similar, likewise the distance from the BB to your grips is likely very similar.

I just bought my most "progressive" geo bike, 510mm reach, 800mm bars, 60mm stem. This means I could easily move to a frame with a 530 reach, and a 40mm stem and *have the same fit.* What do you not understand about that? Sounds extreme on paper, but pretty basic math.



> In the larger sizes balance is severely compromised by this front to rear ratio. The longer the front, the more you reduce pressure on the front tire. Since STA has no bearing while descending and reach has grown, riders fit short stems, further reducing front end grip. Most riders also like a higher handlebar height reducing front end grip even more.


Bla bla bla, if this multi compounded loss of front end grip were real people would be crashing in every turn and nobody would be buying new bikes because they can't go around corners. You just lack understanding of what is going on with geometry.



> Larger bike NEED longer stays! This helps climbing traction, puts weight on the front wheel without hand pressure and lets you run high handlebars, further reducing hand pressure.


Longer stays reduce climbing traction unless you intentionally keep your weight back, it's physics. Likewise when you stand up and your weight is shifted forward, the rear wheel loses traction on long chainstays. This no longer happens with short chainstays because the rear wheel is tucked under the rider more.

Larger bikes do not _need_ longer chainstays unless you're looking for more stability at high speed.



> Reach has settled into about the perfect range and longer just for longer is not really need.


If I want to ride a bike with a shorter stem, I need a longer Reach since the distance from the saddle to the handlebars doesn't change.



> Stems are too short. This reduces front end weight and is used to speed up the extra wide bars and super slow steering geometry. 50mm is the sweet spot. Short travel bikes should be longer.


Again, losing weight on the front end? All this talk of short stems and no mention of Stack, BB height, or wheelbase. Hmm.

I'm no expert, and I'm not a frame builder or engineer, but I know better than to single out one or two dimensions instead of seeing the whole picture. It's a package deal, every dimension and proportion needs to be considered.



alexbn921 said:


> Tuning suspension and building race cars was my background in collage and now I'm an electrical engineer. I like to geek out on this stuff, trying to find the why it works and how to make it better.


The Ripmo receives extremely positive remarks from literally everyone that rides it. It's pretty ridiculous. But, it's not super progressive geometry wise. 435 chainstays, 76 STA, rather modest reach. Is this your reference point? Are you saying YOUR bike is too extreme or are you reading about other bikes based on an online geometry chart and determining that it's too extreme? Sounds like the latter since you speak highly of your Ripmo.


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## PuddleDuck (Feb 14, 2004)

*OneSpeed* said:


> What you seem to fail to recognize is that the "fit" of modern bikes isn't all that different than older bikes. *A large is still a large.* The distance between your saddle and the handlebar is likely very similar, likewise the distance from the BB to your grips is likely very similar.
> 
> I just bought my most "progressive" geo bike, 510mm reach, 800mm bars, 60mm stem. This means I could easily move to a frame with a 530 reach, and a 40mm stem and *have the same fit.* What do you not understand about that? Sounds extreme on paper, but pretty basic math.


That's one perspective regarding "fit". Another perspective is that fit is the saddle's position relative to the BB, and then the bar is positioned relative to the saddle.


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## *OneSpeed* (Oct 18, 2013)

PuddleDuck said:


> That's one perspective regarding "fit". Another perspective is that fit is the saddle's position relative to the BB, and then the bar is positioned relative to the saddle.


Agreed. I guess I was focusing on the metrics the OP was focusing on since he seems to ignore the other variables.

As other posters pointed out, XL bikes used to require an offset seatpost even though they had 73 degree STA's. Now with a 77 STA and zero offset seatpost, the pedaling position feels extremely natural.

People who haven't test ridden a variety of modern bikes will have a hard time understanding that. Clearly. It sounds extreme on paper. I've ridden mid travel trail bikes with as much as 78.2 degree STA's and it wasn't too much. But, the rest of the dimensions need to be balanced with that figure.


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## Forest Rider (Oct 29, 2018)

2016 Stumpjumper = 74*
2019 Chameleon = 72.6*

I actually feel more comfortable on the Stumpy, saddle position is somewhat neutral with an offset head on the Command post.

Chameleon has no offset head and I have the seat forward as much as the seat rail will allow. This position was to compensate for the longer reach that didn't work well with me.
I feel the position of the Chameleon allows my foot to slide off the pedal as it feels like I am pushing a touch more forward.
Both bikes are equipped with Chester pedals.
On my first ride, my foot kept slipping off the pedal wearing the same shoe as always, old trail running shoes, and never had that situation with the Stumpy for 3 years.

I immediately purchased a flat pedal shoe which fixed the problem. I do occasionally slip though. Truth be told, that situation may have been before I slid the seat forward.

I should build a giant protractor and learn the angle of the two bikes with the current saddle position factored in to see if my Stumpy is still steeper or if it's the Chameleon because of the saddle position.

At the end of the day I can ride both just as fast up a hill or when seated on fast flat sections. I do not race, so every second doesn't matter to me. Neither bike gives me pain, however the flat pedals may help with that instead of being locked into a position that my knee may not like for the duration of the ride.

I do prefer the pedal position of the Stumpy over the Chameleon if somebody needed a definitive answer about my favorite position between the two.


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## *OneSpeed* (Oct 18, 2013)

Forest Rider said:


> 2
> I should build a giant protractor and learn the angle of the two bikes with the current saddle position factored in to see if my Stumpy is still steeper or if it's the Chameleon because of the saddle position.


This is a metric that can be useful, but only for you. Everyone's body proportions are different. Long legs, vs torso, vs arms, everyone fits different. There is no magic seatpost angle, or Reach, or stem length that works for everyone. This is why adjustability is built into every bike, and why there are aftermarket solutions to make your bike handle and perform how you like. Not to mention personal preference, local terrain, riding style, level of fitness, etc.

This is why there are a variety of brands offering a variety of geometries. If the same thing worked for everyone, there would be one brand that made 1 bike available in 4 sizes and there would be one tire that worked the same everywhere. That would cover everything.

And if I were running the company they would all be steel SS 29ers, and the cycling world would be a much more boring place.


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## Unbrockenchain (Aug 21, 2015)

alexbn921 said:


> Specialized 2020 kenevo is 77 STA.


That's a freakin ebike...that don't count!!


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## alexbn921 (Mar 31, 2009)

Forest Rider said:


> I should build a giant protractor and learn the angle of the two bikes with the current saddle position factored in to see if my Stumpy is still steeper or if it's the Chameleon because of the saddle position.


I set up a camera and position all of my bikes BB in the same spot so that I could take pictures and overlay them. It was an experiment ot see how much different they actually were.
Here is my XL blur overlaid on my Tallboy 3 XXL


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## alexbn921 (Mar 31, 2009)

Unbrockenchain said:


> That's a freakin ebike...that don't count!!


LOL. kill it with fire.


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## scottzg (Sep 27, 2006)

*OneSpeed* said:


> Let's try this again. You've done a poor job of explaining your gripe and haven't given any specific references. You also contradict yourself.
> 
> You write your OP as fact. You're not offering your opinion, you're making statements as though they are fact. You are not asking if it's the best for every bike, or what others think, just boldly stating that it's wrong somehow.


I'm fascinated by this topic, but this is why i haven't replied. There's too much contradictory oddness in the OP to dissect, and then most of the replies are approaching frame design from a consumer's perspective, which is backward.

*OneSpeed* has great input, and seems to have the clearest understanding of this stuff in the thread. I don't share his short chainstay fetish (personal preference), but if you're tall and skimming this thread for good info... just read his posts.


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## 93EXCivic (Mar 12, 2018)

Forest Rider said:


> 2016 Stumpjumper = 74*
> 2019 Chameleon = 72.6*
> 
> I actually feel more comfortable on the Stumpy, saddle position is somewhat neutral with an offset head on the Command post.
> ...


Are those angles sagged? Because the hardtail's angle is going to get steeper as the front end compresses and the rear doesn't so I bet the seat angle isn't that much different when you are sitting on the bike just pedalling along.

Sent from my LG-H910 using Tapatalk


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## EatsDirt (Jan 20, 2014)

PuddleDuck said:


> Humans bodies aren't identical. Some peeps need steeper seat tubes because of their anatomy, some need slacker seat tubes. From my perspective angles are too steep, but I can understand, AND I can accept, that others need steeper angles.


Hey man, save all that rational thought stuff for real life.

This is the internet, and people need a place to voice their absolute opinions as if they are fact. Studies show this to be true, in my opinion.


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## Forest Rider (Oct 29, 2018)

93EXCivic said:


> Are those angles sagged? Because the hardtail's angle is going to get steeper as the front end compresses and the rear doesn't so I bet the seat angle isn't that much different when you are sitting on the bike just pedalling along.
> 
> Sent from my LG-H910 using Tapatalk


That's a good point. Right, I have not taken into consideration how the Stumpy slackens when I droop the rear suspension. Thanks for the reminder. And maybe good reminder to OP that perhaps his 'steep' seat tube isn't as steep as anticipated.

I'm (personally) not considering the front as I'm not typically riding a low front end while seated. Both bikes would sink similarly while only sitting in the front which would cancel out one another. But yeah the fully suspension would also sag in the rear whereas the hard tail will only droop in the front.

Good chat guys.

________________

And I wasn't trying to preach that the steeper angle is better.
I was just trying to comment from my experience in how the two bikes feel different and where my preference lies. One isn't better than the other for me despite their differences.
If I preferred a long reach I could probably slide the seat rearward. It's just that the longer reach, compared to my stumpjumper, fatigues my shoulders if my ride day has a lot of slow and steep climbing. Requires more effort to hold myself forward.
And in one occasion during long training, my triceps were toast. I rolled the bars back a tad to make the triceps work less.
I've got the bike pretty well adjusted to me for my style and conditions and it's a crap-load of fun.
As a matter of fact, I hit one of my top 3 times on the hard trail in this setup last weekend on a 5 minute downhill (Thank you Strava for verifying that I didn't only feel fast).

I really enjoy riding both my bikes.


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## Schulze (Feb 21, 2007)

With my (measured, effective) 73.3 sta I can climb a 45% grade. That's convenient because the steepest grades on normal trails rarely gets to 35% and just for a very short time. There is no reason for me to ever buy a trail bike with a steeper sta than 73 degrees.


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## matt4x4 (Dec 21, 2013)

There is a syndrome that has become an epidemic
Its EGO
It is Look At Me
Its I know numbers
Look at me
I am important

Yet there is a virus as well that has become an epidemic
Its the snowflake culture.

I am not saying that the OP is such.
I am figuring it is more of a deal where people just post whatever is on their mind and I think that is where it lays in this circumstance. Ego also applies undoubtedly. Padding the post count and boredom.

We could complain about a lot of other things going on in this great big world of ours. Like tapered headsets, through axles, mass produced junk, plastic straws and bags, children starving in Africa, Genocide, Nukes, Slavery, Child trafficking, Human Smuggling, Border Walls, Organ trafficking, Street Racing, Murderous Rampages with firearms, global warming, illegal toxic dumping.



jcd46 said:


> Why are people so hang up on numbers? I go from one bike to another and don't give it a second thought after a few seconds of adjusting.
> 
> Pedal and have fun.


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## *OneSpeed* (Oct 18, 2013)

Schulze said:


> With my (measured, effective) 73.3 sta I can climb a 45% grade. That's convenient because the steepest grades on normal trails rarely gets to 35% and just for a very short time. There is no reason for me to ever buy a trail bike with a steeper sta than 73 degrees.


I don't understand this. Odd that you're so strongly opinionated about something you've never experienced?


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## Schulze (Feb 21, 2007)

*OneSpeed* said:


> I don't understand this. Odd that you're so strongly opinionated about something you've never experienced?


The numbers are right there. What am I missing by going to a shorter cs for a worse pedaling position with more weight on my hands? My terrain is hilly but very pedally. I don't do 1hr climbs followed by a long descent.


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## BansheeRune (Nov 27, 2011)

Round peg in triangular holes once more...

We are all crash test dummies and require the exact same dimensions and angles on all classes of bikes regardless of anything else.


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## Forest Rider (Oct 29, 2018)

Schulze said:


> The numbers are right there. What am I missing by going to a shorter cs for a worse pedaling position with more weight on my hands? My terrain is hilly but very pedally. I don't do 1hr climbs followed by a long descent.


I think what he is saying is validated by your recent comment.
You state that steeper is a worse position.

I'm sure he was asking, how you can assume it is worse if you haven't tried.

Meh, the conversation is going nowhere anyway. Keep us clicking the 'recent comments' though. Something to do over coffee. ha


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## *OneSpeed* (Oct 18, 2013)

Schulze said:


> The numbers are right there. What am I missing by going to a shorter cs for a worse pedaling position with more weight on my hands? My terrain is hilly but very pedally. I don't do 1hr climbs followed by a long descent.


I understand you're quite content riding your current bikes, and that's great. But confidently dismissing something you've never tried when clearly that's the way the whole industry is going just seems like sticking your head in the sand.

Lalalala I can't hear you lalalalala.


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## Schulze (Feb 21, 2007)

Oh, I gotcha. I've demo'd some of the steeper short bikes like the Ripley and 5010 and found the opinions of alexbn921 in the original post to be accurate wrt pedaling position. Are people arguing this point? I guess I'd have to ask him, do you value a good pedaling position or live in an area where it's important? 

What I am asking is, given the current system state, WHY do I need to move my saddle 2 inches forward? I have posted the current system state so you can judge for yourself as well. 

Maybe what we really need is a more adjustable saddle/seatpost interface.


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## Schulze (Feb 21, 2007)

*OneSpeed* said:


> I understand you're quite content riding your current bikes, and that's great. But confidently dismissing something you've never tried when clearly that's the way the whole industry is going just seems like sticking your head in the sand.
> 
> Lalalala I can't hear you lalalalala.


You're really confident that you're making a point here, but it's only between your ears and has no relation to reality.


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## alexbn921 (Mar 31, 2009)

Road bikes are a different animal, but each size bigger gets a slacker STA and longer stays. Mountain bikes need some size specific elements.
You can't add 100mm to the front of the bike and expect that everything just works out. There will always be a sweet spot in front to back ratio for a given size and STA is a similar item.

Bikes have grown over the last decade and a stays have shrunk. This is great for small/medium riders and gives us large guys bikes that have enough reach, but it messes with the balance. I have ridden bikes that have gone too far and felt the compromise in handling.

If we want to talk about a specific bike lets use the Ripmo. It increases the effective STA with each size to give a similar seated STA between sizes. The ratio front to rear on the XL is right on the edge of being unbalanced. It's a great bike, but could be better for me with a few tweeks. Slightly less STA and longer rear stays. 

Bikes are exceeding 500 reach with slack HTA. They have huge front centers and steep STA keeps the seated sizing the same, standing descending is very different from bikes a couple of generations ago. This is the point around which I believe bikes need to adapt with longer stays or even shorter fork offsets.

I don't believe there is a perfect ratio or one size fits all geo. BB height,HTA, STA suspension design, local terrain and rider style all play a roll.


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## scottzg (Sep 27, 2006)

alexbn921 said:


> Road bikes are a different animal, but each size bigger gets a slacker STA and longer stays.


They've finally gotten away from that. It was a holdover from the lugged era, when 1" top tubes and 1.125" downtubes were required because lugs and wheelbase dictated application.

It's engineering around a problem, not something to emulate.


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## alexbn921 (Mar 31, 2009)

scottzg said:


> They've finally gotten away from that. It was a holdover from the lugged era, when 1" top tubes and 1.125" downtubes were required because lugs and wheelbase dictated application.
> 
> It's engineering around a problem, not something to emulate.


Uhh, no they haven't. Every single road bike made is still like this. They change the HTA and fork offset too.


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## EatsDirt (Jan 20, 2014)

alexbn921 said:


> Uhh, no they haven't. Every single road bike made is still like this. They change the HTA and fork offset too.


Not every road bike model/brand does this. See Giant.


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## Smackem (Sep 2, 2019)

Road bike chainstay length is determined by bike intended purpose. Road bikes is mainly head angle and seat angle.


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## alexbn921 (Mar 31, 2009)

Pinarello
Specialized
Trek
Cannondale minus the CSL
Eddy Merckx
Scott
........
All adjust CSL, HTA and STA based on size. Not really an antiquated hold over from lugged bikes like you said.


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## jeremy3220 (Jul 5, 2017)

While we're arguing...I also find the complaints about increased pressure on hands somewhat true but also funny. When someone on here would complain about increased hand pressure from an XC type low bar setup (-stem angle, low stack, etc) the old school crowd would just say to strengthen your core. Now they complain about steep seat tubes causing increased hand pressure.


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## Jwiffle (Jan 26, 2004)

I'm fairly tall, about 6'1". I like the new geometry. I always had to have the seat all the way forward, and still perched on the nose during climbs. Now I can sit on the saddle while climbing. 

I also like the wide bars and short stems, having the reach built into the frame instead. Every new bike I've had has gotten wider bars, and I always think I'll probably cut them, then find I like them. So I'm on 800mm bats and a 35mm stem on my new bike. Love it. 

The short chain stays also work. I'm not as hung up on the chain stay length. Quarter inch or even half inch longer stays probably wouldn't make much difference to me and how I ride, but the short works well, so I'll run with it. 

Sorry, OP, your opinion is your own, and I'm glad you're not in charge of all bike design for tall people.


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## Miker J (Nov 4, 2003)

So, let's say you have a seat tube angle of 74. All other things being equal that changes to an angle of 77. Say on a fellow with a 34 inch inseam. I'm coming up with about a 3 inch forward change. Does that math sound about right?


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## Schulze (Feb 21, 2007)

jeremy3220 said:


> While we're arguing...I also find the complaints about increased pressure on hands somewhat true but also funny. When someone on here would complain about increased hand pressure from an XC type low bar setup (-stem angle, low stack, etc) the old school crowd would just say to strengthen your core. Now they complain about steep seat tubes causing increased hand pressure.


The more you can relax, the less energy you use. On the road bike, where the position puts more pressure on the hands than a low xc setup, the shape of the drop bars and hoods allows this with no discomfort. It's the flat bars with high pressure that I just can't get to work right. Maybe in the future someone will figure out a brake hood type position for the mtb with good width and appropriate shifter and brake technology. Right now that doesn't exist.


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## tigris99 (Aug 26, 2012)

As a 6'1 clyde I have somewhat agree with the OP only with the point that I like the 73ish STA we were seeing. But shorter stays are nice IMHO because it makes bigger wheels/tires feel more nimble.

But the "loss of power" isnt what is mentioned. Its muscles are conditioned to what a rider is used to, a serious change like that may take a bit to condition to. I did notice it going from my other bikes to test riding my new Stumpy (on layaway, almost paid off). Legs felt like they were working harder vs even my fat bike.

But like anything, its personal preference. Dont gave to spend a small fortune for a custom bike, just browse brands. Ignore what others are riding and go after what you want. My latest bike purchase I had to sacrifice ideal STA (for easy cockpit set up) for the other bits that mattered more to me. STA is one thing that is so easy to "fix".

Sent from my SM-N975U using Tapatalk


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## Thustlewhumber (Nov 25, 2011)

TBH the OP is really just describing a recumbent.


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## str8edgMTBMXer (Apr 15, 2015)

not hating, but... 

man...this is all exhausting...do people really put this much math into their riding? I think if I went down this numbers route I would never actually find/be happy with a bike...

in some way's I wish i understood all of this. I have been following this thread seeing if I can learn something...

in others, I never want riding to come down to these kinds of "absolutes"/parameters... 

keep going!


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## Forest Rider (Oct 29, 2018)

str8edgMTBMXer said:


> not hating, but...
> 
> man...this is all exhausting...do people really put this much math into their riding? I think if I went down this numbers route I would never actually find/be happy with a bike...
> 
> ...


I agree. I've read points about the various angles and have learned nothing.
This is far from a teaching thread.

I am also glad that I got a bike before I thought I needed to know all this **** because I'd probably still be researching 3 years later and still not have a bike because they are all flawed.

People complain about too many people on a trail.
People complain that the bike they have has poor geometry.

Too bad people can't just enjoy riding a bike anymore. (no that doesn't apply to everybody)


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## jeremy3220 (Jul 5, 2017)

str8edgMTBMXer said:


> not hating, but...
> 
> man...this is all exhausting...do people really put this much math into their riding? I think if I went down this numbers route I would never actually find/be happy with a bike...


It's not so much math as it is experiencing a variety of different geo's. My previous full suspension bike had a STA that was too slack. I had to work to keep the front down and shift my weight forward on climbs that I shouldn't have to work that hard. I'm really happy with the geo on my current bikes.


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## mlx john (Mar 22, 2010)

matt4x4 said:


> We could complain about a lot of other things going on in this great big world of ours. Like tapered headsets, through axles, mass produced junk, plastic straws and bags, children starving in Africa, Genocide, Nukes, Slavery, Child trafficking, Human Smuggling, Border Walls, Organ trafficking, Street Racing, Murderous Rampages with firearms, global warming, illegal toxic dumping.


Why would anyone complain about through axles?


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## alexbn921 (Mar 31, 2009)

mlx john said:


> Why would anyone complain about through axles?


Go on the road bike forums. They hate thru axles and disk brakes.


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## str8edgMTBMXer (Apr 15, 2015)

jeremy3220 said:


> It's not so much math as it is experiencing a variety of different geo's. My previous full suspension bike had a STA that was too slack. I had to work to keep the front down and shift my weight forward on climbs that I shouldn't have to work that hard. I'm really happy with the geo on my current bikes.


true...where I live, it is pretty hard to get test rides on a variety of bikes, so I can see where people who have that opportunity could get into it on this level. I am that way about my other loves - drums and bass guitars - but that is also my career, so the research also (sort of) makes my living


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## Fleas (Jan 19, 2006)

I just demo'd a Pivot Trail 429 yesterday. Size XL. The reach was short (at least there was room for a longer stem). Chainstays felt like I was towing something.
I recently replaced a large size 2013 Canfield Nimble 9 with an XL 2018 Canfield Nimble 9. The cockpit was only 10mm longer. I went "way" down to an 80mm stem. :???:

Yes, the seat tube angle thing has gone too far. I don't want to be in front of my bottom bracket. (at least that's how it feels). My knees are in front of my pedals - that feels weird. Maybe I'll get used to it. Maybe I'll _have_ to get used to it. Maybe they'll start making longer seat rails.

I don't remember the last time I had trouble climbing anything other than from being tired.

Chainstays are not too short. 

-F


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## BushwackerinPA (Aug 10, 2006)

I'm 5'8 and riding a 2014 Trance SX size L with the saddle pushed all the way up(STA could be steeper IMO), 35mm stem and swept back bars. I choose this fit because its absolutely shreds going down and climb back up pretty well.

IMO I love the long front center with short stem because it means I can keep moving towards the front of the bike with out risk of endo on technical terrain. I also feel that if I am more active I can make better turn on my size L Trance on my 5'5 wife's Size M trance. I am way faster on this bike than my old 2011 size M trance.






this bike has a 464mm reach, and I also own size M honzo with a 450mm reach. I honestly will never ride less than 450mm reach again despite only being 5'8.


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## Curveball (Aug 10, 2015)

Vader said:


> They have a small hand full of aluminum frames left which is what I'm after.


I really dig mine a lot.

It's the best bike I've ever ridden.


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## Curveball (Aug 10, 2015)

Schulze said:


> The more you can relax, the less energy you use. On the road bike, where the position puts more pressure on the hands than a low xc setup, the shape of the drop bars and hoods allows this with no discomfort. It's the flat bars with high pressure that I just can't get to work right. Maybe in the future someone will figure out a brake hood type position for the mtb with good width and appropriate shifter and brake technology. Right now that doesn't exist.


I wonder if TOGS might work for you?


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## stripes (Sep 6, 2016)

Curveball said:


> I really dig mine a lot.
> 
> It's the best bike I've ever ridden.


Both the AL frames and revved frames are amazing.


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## matt4x4 (Dec 21, 2013)

They sure do love their Lycra's and cantilevered brakes, no disc brakes for them.



alexbn921 said:


> Go on the road bike forums. They hate thru axles and disk brakes.


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## robnow (Apr 12, 2010)

2020 Norco Sight released today...fantastic geo! Steepening SA and longer chainstays with an increase in frame size, YES PLEASE, Norco along with Forbidden Bikes. This is the direction I hope to see more companies gravitate to in the next iterations of their rides.


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## Suns_PSD (Dec 13, 2013)

When I purchased my Foxy 29 last year I was pleased with it's not to steep, but steep enough, 75.5 degree seat tube angle. It was a nice improvement in all ways over my previous Yeti's 73.3 STA. 
In a short time my quads got used to the new angle and I was climbing like never before. 
Then I slid my seat as far forward as it would go and got use to that. 
Now I'm noticing on every grade (which is a majority of every trail I ride) I'm naturally gravitating to the very front tip of my seat. Left with the conclusion that I'd be even happier with an even steeper seat tube angle. I don't know what the limit is for how I ride and have no intention of changing bikes for years, but I see room for improvement in a steeper seat tube angle for my needs.
There was never any question about the other modern dimensions. 

Sent from my SM-G892A using Tapatalk


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## alexbn921 (Mar 31, 2009)

robnow said:


> 2020 Norco Sight released today...fantastic geo! Steepening SA and longer chainstays with an increase in frame size, YES PLEASE, Norco along with Forbidden Bikes. This is the direction I hope to see more companies gravitate to in the next iterations of their rides.


Norco increases rear stays 5mm for each size. Bravo Norco. They also increase STA with each size which moves taller riders much more forward even with our increased seat height.


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## alexbn921 (Mar 31, 2009)

Suns_PSD said:


> When I purchased my Foxy 29 last year I was pleased with it's not to steep, but steep enough, 75.5 degree seat tube angle. It was a nice improvement in all ways over my previous Yeti's 73.3 STA.
> In a short time my quads got used to the new angle and I was climbing like never before.
> Then I slid my seat as far forward as it would go and got use to that.
> Now I'm noticing on every grade (which is a majority of every trail I ride) I'm naturally gravitating to the very front tip of my seat. Left with the conclusion that I'd be even happier with an even steeper seat tube angle. I don't know what the limit is for how I ride and have no intention of changing bikes for years, but I see room for improvement in a steeper seat tube angle for my needs.
> ...


If you take my inseam of 36 and compare it to a small riders of 28 you have 8 inches of differential. Let's say that my femur is 4 inches longer and we are both on the new Norco with 78 deg STA. With my seat 8 inches higher I get over a inch of reduced setback vs the shorter rider.
sin 22 degrees * 8 = 3.


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## isleblue65 (Sep 5, 2009)

*OneSpeed* said:


> Wow, what a wonderful example of someone who either hasn't spent a fair amount of time on "modern geometry" trail bikes, OR just doesn't understand bike geometry.
> 
> This sounds like arm chair quarterback complaining instead of real world experience talking.
> 
> ...


OP experience aligns almost perfectly with mine. I'm 6'4", and have experienced all of the issues he has with my XL Ripmo.

Initially, power to the cranks was less than on my previous bike, until I built up the quads - because knees pushed further forward. Wrist and hand pain sucked for 6 - 7 months until I installed a super short 35mm riser stem, lots of spacers underneath and carbon 35mm riser bars. Then there's the Ergon grips, Ergon saddle, lower fork pressure and lower tire pressure - all to make the bike tolerable to ride because geometry has gone too far. Oh, there was also a professional fitting in there too.

Saying that, this is the best climbing and descending bike I've ever owned. It's a blast to ride, and now that finally have it setup to where I can physically ride it without discomfort, I love it.

However, it's ridiculous that it should take so much effort to get a new bike to work for you. Hindsight, I may have just bought the less modern geometry Specialized StumpJumper or something that would have been comfortable out of the box.

Onespeed - you are completely full of **** and have no idea what you are talking about.

Sent from my iPhone using Tapatalk


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## *OneSpeed* (Oct 18, 2013)

isleblue65 said:


> *However, it's ridiculous that it should take so much effort to get a new bike to work for you. Hindsight, I may have just bought the less modern geometry Specialized StumpJumper or something that would have been comfortable out of the box. *


No single bicycle is perfect for everyone or else we'd all be riding the same bike, and it would be the only one available.

Do I need to say it? Body proportions, personal preference, local terrain, riding style, setup, etc. all influence what is the right or wrong bike for you.

Sounds to me like you just don't have a good understanding of how you want your bikes set up, or how they should fit. Yes, there may be a bit of a learning curve with newer bikes if you're coming off an older bike, but that doesn't mean it's wrong or worse. Just different.

Now that you have the bike set up properly you seem to like it, so guess you're on board with modern geo? The OP seems to hate modern geo, or rather just not understand it, you seem to like it.

As has been stated before, the Ripmo is far from the most progressive geo out there, but if riding the Spesh puts a bigger smile on your face, then that's the right bike for you.



> Onespeed - you are completely full of **** and have no idea what you are talking about.


Perhaps you missed post #64 that goes into more details about the specifics, that the OP still hasn't responded to.


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## alexbn921 (Mar 31, 2009)

*OneSpeed* said:


> Now that you have the bike set up properly you seem to like it, so guess you're on board with modern geo? The OP seems to hate modern geo, or rather just not understand it, you seem to like it.


I love modern geometry and understand it. My whole point that you completely missed is that riders of different heights have different needs based on body composition.

There is an optimum geometry related to frame size. For years rear ends were way too long for shorter riders. Now they are in the perfect range for a medium frame on most bikes. For years, reach was way too short for everyone. Now it's reaching the point of how much is too much? I still want more than 500 reach, but need a longer rear to balance it out. STA should be slacker the taller you are, but was too slack on old bikes to make up for the short reach.

I'm looking for balance, parity of sizing and a productive conversation on the preferred setup of riders. Especially people on small, XL and XXL bikes as they are most affected by being at the extreme end of bike fit.


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## aerius (Nov 20, 2010)

alexbn921 said:


> I love modern geometry and understand it. My whole point that you completely missed is that riders of different heights have different needs based on body composition.
> 
> There is an optimum geometry related to frame size. For years rear ends were way too long for shorter riders. Now they are in the perfect range for a medium frame on most bikes. For years, reach was way too short for everyone. Now it's reaching the point of how much is too much? I still want more than 500 reach, but need a longer rear to balance it out. STA should be slacker the taller you are, but was too slack on old bikes to make up for the short reach.
> 
> I'm looking for balance, parity of sizing and a productive conversation on the preferred setup of riders. Especially people on small, XL and XXL bikes as they are most affected by being at the extreme end of bike fit.


That is unlikely. The vast majority of riders and bike companies aren't even aware that different sizes of the same bike model will have significant differences in handling. Norco is one of the very few manufacturers which has recognized that adjusting chainstay lengths & seat tube angles is necessary to keep weight balance & fit consistent across the size range, but even that isn't enough. If we want every size in a given model to handle & fit the same way, everything needs to change on every size. Wheelbase has a significant influence on the high speed stability of the bike as does the BB drop, an XS is going to be less stable than an XL unless a bunch of changes are made to the geometry. Suspension kinematics will likely need to be tweaked as well to better match the average rider size & weight at each size.

But that's not going to happen since the bike industry in general is run by marketing departments who want to sell you new crap instead of actually solving problems.


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## isleblue65 (Sep 5, 2009)

*OneSpeed* said:


> Now that you have the bike set up properly you seem to like it, so guess you're on board with modern geo? The OP seems to hate modern geo, or rather just not understand it, you seem to like it.


I have setup a dozen bikes in my 30 years of mountain biking, and know how to do it. Where I ended up with the Ripmo through adjustments at the extreme end of the scale: (saddle all the way back, handlebars way up and back, cleats all the way back to push feet forward, soft suspension and tires and carbon bars and Ergon grips to soften weighted hands, is closer to the geometry of a few years ago. That's what feels comfortable for myself and a lot of taller people.

I'm still taking advantage of the benefits of the shorter chain stay, slack HT and steep ST, and the bike handling, but have adjusted some of it out for comfort. I'll keep the bike because I've learned to love it, but definitely not on board with it in the sense that if I was in the market for a bike today, I would be looking for slacker ST, shorter reach, etc. Anything more progressive would be too progressive, and even the Ripmo went too far.

Sent from my iPhone using Tapatalk


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## jeremy3220 (Jul 5, 2017)

isleblue65 said:


> OP experience aligns almost perfectly with mine. I'm 6'4", and have experienced all of the issues he has with my XL Ripmo.
> 
> Initially, power to the cranks was less than on my previous bike, until I built up the quads - because knees pushed further forward. Wrist and hand pain sucked for 6 - 7 months until I installed a super short 35mm riser stem, lots of spacers underneath and carbon 35mm riser bars. Then there's the Ergon grips, Ergon saddle, lower fork pressure and lower tire pressure - all to make the bike tolerable to ride because geometry has gone too far. Oh, there was also a professional fitting in there too.
> 
> ...


Sounds like the bike is a bit too small. If you have to change stem and bars to get the grips high enough I'd argue the stack is too low on your frame. I'm 6'5" and found it small for my liking. I'm on a Megatower which is a properly big bike (high stack too). Hand pressure is not an issue on this bike.


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## *OneSpeed* (Oct 18, 2013)

alexbn921 said:


> There is an optimum geometry related to frame size.


Really, interesting. This one magical geometry must surely apply to all bikes then? XC, DH, road?

You think that's true or do you think there's an optimum geometry for YOU?


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## alexbn921 (Mar 31, 2009)

*OneSpeed* said:


> Let's try this again. You've done a poor job of explaining your gripe and haven't given any specific references. You also contradict yourself.
> 
> You write your OP as fact. You're not offering your opinion, you're making statements as though they are fact. You are not asking if it's the best for every bike, or what others think, just boldly stating that it's wrong somehow.


My perspective. I am writing from my 30+ years of experiences on mountain and road bikes.



*OneSpeed* said:


> How so? Seems most people really like the new bikes, geometry included. Most brands are following these trends and it's done great things for the handling of 29ers in particular. Early days were no bueno for 29ers.


I love new bikes, they are much better. Any trade offs are worth it for the increases in almost every area of riding. That doesn't mean they are perfect. This is especially true for small and very tall riders.



*OneSpeed* said:


> Often, Yes. *It's a package deal.* Short chainstays, steeper STA, lower BB, longer front center, much longer Reach, much shorter Stem. When executed properly it's magical.


Yep. So there is absolutely no room for improvement? Bikes will forever be as they are?



*OneSpeed* said:


> What you seem to fail to recognize is that the "fit" of modern bikes isn't all that different than older bikes. *A large is still a large.* The distance between your saddle and the handlebar is likely very similar, likewise the distance from the BB to your grips is likely very similar.


True that ETT is mostly the same, but fit is different. Seat to bb angle has shifted forward along with body position. Weight distribution while standing has changed dramatically too.



*OneSpeed* said:


> I just bought my most "progressive" geo bike, 510mm reach, 800mm bars, 60mm stem. This means I could easily move to a frame with a 530 reach, and a 40mm stem and *have the same fit.* What do you not understand about that? Sounds extreme on paper, but pretty basic math.


The math checks out. :thumbsup:



*OneSpeed* said:


> Bla bla bla, if this multi compounded loss of front end grip were real people would be crashing in every turn and nobody would be buying new bikes because they can't go around corners. You just lack understanding of what is going on with geometry.


It's not a binary change. It's a small shift in weight balance each time a bike gets longer in the front and shorter or the same in the back. A tallboy 3 for example has 100mm reach between the Small and XXL with the same rear end. At some point in that bikes sizing someone is getting screwed.



*OneSpeed* said:


> Longer stays reduce climbing traction unless you intentionally keep your weight back, it's physics. Likewise when you stand up and your weight is shifted forward, the rear wheel loses traction on long chainstays. This no longer happens with short chainstays because the rear wheel is tucked under the rider more.
> 
> Larger bikes do not _need_ longer chainstays unless you're looking for more stability at high speed.


While standing a short rear end adds climbing traction. For seated climbing a longer rear takes nothing away, unless it's crazy out of proportion. For tall riders a short rear ends limits your seated climbing grade. We wheelie under power with our weight higher up and further back.

Stability at speed is not why I want longer stays. Balance is.



*OneSpeed* said:


> If I want to ride a bike with a shorter stem, I need a longer Reach since the distance from the saddle to the handlebars doesn't change.


Yep. Basic math again. Although steep STA moves the seat forward and necessitates even longer reach.



*OneSpeed* said:


> Again, losing weight on the front end? All this talk of short stems and no mention of Stack, BB height, or wheelbase. Hmm.
> 
> I'm no expert, and I'm not a frame builder or engineer, but I know better than to single out one or two dimensions instead of seeing the whole picture. It's a package deal, every dimension and proportion needs to be considered.


Stack and reach is based on BB location not height. Again, XL bikes tend to use longer cranks and need more BB height to maintain similar riding position. Stack is the most adjustable variable on bikes. Yes it should be proportional to bike size and lucky builders try to optimize it.



*OneSpeed* said:


> The Ripmo receives extremely positive remarks from literally everyone that rides it. It's pretty ridiculous. But, it's not super progressive geometry wise. 435 chainstays, 76 STA, rather modest reach. Is this your reference point? Are you saying YOUR bike is too extreme or are you reading about other bikes based on an online geometry chart and determining that it's too extreme? Sounds like the latter since you speak highly of your Ripmo.


I love my XL Ripmo, it is the best bike I have ever ridden! I picked it specifically for it's incredible DW suspension and overall geometry. Even the small details like internal cable tubes, threaded BB, water bottle mounts and 2.6 tire clearance.

I want it to be 20-30 longer, but not without longer stays to match. It's already on the tipping point for weight balance.

I would like to move my seat back 5-10mm, but I can't and my seat already has a rearward seating position.

BB height is low, but not too low. Again this a compromise and I have dragged level pedals in g-out landings. The DW link rides high and I have a relatively firm setup.

Wheelbase doesn't matter to me, 1200mm is not a barrier that can't be passed. Bikes should be proportional.


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## alexbn921 (Mar 31, 2009)

aerius said:


> That is unlikely. The vast majority of riders and bike companies aren't even aware that different sizes of the same bike model will have significant differences in handling. Norco is one of the very few manufacturers which has recognized that adjusting chainstay lengths & seat tube angles is necessary to keep weight balance & fit consistent across the size range, but even that isn't enough. If we want every size in a given model to handle & fit the same way, everything needs to change on every size. Wheelbase has a significant influence on the high speed stability of the bike as does the BB drop, an XS is going to be less stable than an XL unless a bunch of changes are made to the geometry. Suspension kinematics will likely need to be tweaked as well to better match the average rider size & weight at each size.
> 
> But that's not going to happen since the bike industry in general is run by marketing departments who want to sell you new crap instead of actually solving problems.


Agreed!
I think that adjustable chips on rear ends and shocks, like santa cruz are a big step forward with no downsides. Gives one rear triangle for both ends of their sizing.

Most front triangles should have slight differences and is easy to do as all of them are unique.


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## alexbn921 (Mar 31, 2009)

*OneSpeed* said:


> Really, interesting. This one magical geometry must surely apply to all bikes then? XC, DH, road?


Absolutely not. That's the whole point. I ride all of them though and see the various ways they all cope with optimizing for each rider size.



*OneSpeed* said:


> You think that's true or do you think there's an optimum geometry for YOU?


Of course there is an optimum geometry for me! There's one for you too and if I was designing a bike i would try to make sure that it fit into the bell curve of users at each size. Having different special parts is cost prohibitive, but something like a flip chip, 2nd link or rear end should cover most situation.

Front triangles don't share parts and are easy (free) to make different. An XL should be much stronger/stiffer than a small for example.


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## aerius (Nov 20, 2010)

alexbn921 said:


> Agreed!
> I think that adjustable chips on rear ends and shocks, like santa cruz are a big step forward with no downsides. Gives one rear triangle for both ends of their sizing.


I think Norco's solution is better. They have a different chainstay length on each size so that the rear centre length increases proportionally to the front centre to keep the rider's centre of mass in the same place on every size.



> Most front triangles should have slight differences and is easy to do as all of them are unique.


They should, but you'd be surprised how often they don't. Lots of manufacturers will recycle the BB junction and the seat tube/top tube section of the moulds for all their frame sizes. And they use the same tubing size for every frame size. Saves them on moulding costs since they can reuse half the parts on every size, but boy does it make things suck.


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## Suns_PSD (Dec 13, 2013)

alexbn921 said:


> If you take my inseam of 36 and compare it to a small riders of 28 you have 8 inches of differential. Let's say that my femur is 4 inches longer and we are both on the new Norco with 78 deg STA. With my seat 8 inches higher I get over a inch of reduced setback vs the shorter rider.
> sin 22 degrees * 8 = 3.


I don't know if the actual set back actually matters as much is the degrees of set back.
I think you want about the same seat angle whether your short or tall. Of course this depends greatly on the actual seat tube perfectly intersecting with the bottom bracket which is rare these days.

Sent from my SM-G892A using Tapatalk


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## Suns_PSD (Dec 13, 2013)

Always struggled with fit on my large yeti 5.5, even after spending a lot of money and time adjusting it. I set up my Mondraker Foxy with modern Geo based on some basic dimensions and right from the get go it felt dramatically better. In fact the only change I ever made to it since that initial set up was I went to a 20mm total wider bar for the 1st time.
As a relatively new rider I'm in the camp that modern bikes are way better. 

Sent from my SM-G892A using Tapatalk


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## PuddleDuck (Feb 14, 2004)

alexbn921 said:


> I would like to move my seat back 5-10mm, but I can't and my seat already has a rearward seating position.


I have a couple of thoughts for you, just in case you haven't already considered them.

1. If you're not already running a set-back dropper, 9.8 makes one

2. Selle SMP saddles might help you in 2 ways
2.1 Their rails are longer than normal
2.2 Front what I've read, most peeps move their SMP saddle forward on the rails compared to the saddle it replaced.
- https://bikerumor.com/2019/03/09/review-selle-smp-avant-saddle-is-odd-on-looks-big-on-comfort/
- https://www.bikeradar.com/reviews/components/saddles/selle-smp-dynamic-saddle-review/ (have a look at the positive comments)

I'm trialing one (down here in Aus there are lots of demo saddles available from LBS's,) and it seems to live up to the reviews.

Check out Steve Hogg's website for more info, he has several posts about them, including which one to buy. 
e.g.: https://www.stevehoggbikefitting.com/bikefit/2011/09/all-about-smps/

Selle SMP also has a new saddle that's flatter - https://www.sellesmp.com/en/f30.html ... though I haven't yet read any reviews that it meets points 2.1 and 2.2 above


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## *OneSpeed* (Oct 18, 2013)

alexbn921 said:


> While standing a short rear end adds climbing traction. For seated climbing a longer rear takes nothing away, unless it's crazy out of proportion. *For tall riders a short rear ends limits your seated climbing grade. We wheelie under power with our weight higher up and further back.*


I don't agree the short rear end "limits" climbing for everyone. Personally, I'd much rather stand up and grind out a steep climb. Short chainstays are an advantage for me.

It's odd that you are asking for a more slack STA, then complain that the front end gets light on steep climbs because your weight is higher and too far back. This is an example of where you contradict yourself. Slightly longer chainstays may help, but I don't think you understand what you're asking for.



> I want it to be 20-30 longer, but not without longer stays to match. It's already on the tipping point for weight balance.


You want a significantly longer reach AND longer chainstays? That sounds like a recipe for bike that turns like a dump truck. What you're asking for in Reach alone is a big move, add longer chainstays (which you didn't quantify) would make for a very long wheelbase.



> I would like to move my seat back 5-10mm, but I can't and my seat already has a rearward seating position.


Again, you're complaining about the front end being too light on climbs, but you want your saddle farther back which will only make it worse. Contradiction.



> Wheelbase doesn't matter to me, 1200mm is not a barrier that can't be passed. Bikes should be proportional.


For the record, your wheelbase is 1249mm if you haven't modified your setup.

_______________

If you're willing to have a discussion about bike geometry, and put some numbers to it, someone here may be able to help shine some light on how to optimize your setup, or recommend a bike that would suite you better *based on your personal desires. *

I don't like your original post because it's extremely vague, misguided, and strongly opinionated. Had you titled it "My take on progressive geometry" I would have had a very different approach, if I commented at all. That title suggests opinion, where as the way you wrote it is stated as fact, and I strongly disagree.

Comparing our two bikes: Yours, Mine

BB height- 341, 342
STA- 76, 76.2
HTA- 65.9, 66
Wheelbase- 1249, 1255

Quite similar so far. Here's what's significantly different.

Reach- 493, 510
Chainstay- 435, 427 
Stack- 642, 625

So, not knowing anything about your fitness, weight, riding style, location, etc. I'd say *if* you got what you were asking for, based on what I'm hearing from you, you'd end up with a very long bike that doesn't go around corners.

I often feel like if people ordered a custom frame with exactly the geometry they wanted, and the builder didn't question their decisions or advise them in any way, they would absolutely hate the bike they end up with.


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## alexbn921 (Mar 31, 2009)

*OneSpeed* said:


> I don't agree the short rear end "limits" climbing for everyone. Personally, I'd much rather stand up and grind out a steep climb. Short chainstays are an advantage for me.


Well I have ridden many bikes that limit my climbing. Just because you don't have a clue doesn't mean it's not a thing.



*OneSpeed* said:


> It's odd that you are asking for a more slack STA, then complain that the front end gets light on steep climbs because your weight is higher and too far back. This is an example of where you contradict yourself. Slightly longer chainstays may help, but I don't think you understand what you're asking for.


Man your dense. It's hard for me to explain to a someone lacking even a basic understanding of bikes in general. Maybe if you had some context we would be on the same page, but that is obviously not the case. I'll explain it like I would to my kids.

Longer stays = a more planted front end on climbs. Good
Longer stays = better balance and allow an even longer front. Good
74-75 degree STA = better pedaling position for me. Good



*OneSpeed* said:


> You want a significantly longer reach AND longer chainstays? That sounds like a recipe for bike that turns like a dump truck. What you're asking for in Reach alone is a big move, add longer chainstays (which you didn't quantify) would make for a very long wheelbase.
> .


Yes i'm tall. I need a big bike. Is that easy enough for you to understand or did it go over your head again?


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## *OneSpeed* (Oct 18, 2013)

alexbn921 said:


> Well I have ridden many bikes that limit my climbing. Just because you don't have a clue doesn't mean it's not a thing.
> 
> Man your dense. It's hard for me to explain to a someone lacking even a basic understanding of bikes in general. Maybe if you had some context we would be on the same page, but that is obviously not the case. I'll explain it like I would to my kids.
> 
> ...


OK, fair enough, I tried.

At least now I know you can't comprehend a single thing I've written in this thread, have ignored the most significant points, and choose to be jerk about it when I was trying to get specific and help (without being rude).

You've completely ignored the most relevant parts of the geometry discussion and focused on attacking me personally.


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## alexbn921 (Mar 31, 2009)

PuddleDuck said:


> I have a couple of thoughts for you, just in case you haven't already considered them.
> 
> 1. If you're not already running a set-back dropper, 9.8 makes one
> 
> ...


Thanks for the tips. I do have a 9point8 dropper and have considered a seat back for it. My saddle of choice is the selle italia flite trans am gel flow titanium from the mid 90's I have 3 of them and have been seeking a lighter saddle for my road bike. I've gone thru 6 different ones and am currently trying out the specialized power acr 143.

SMP saddle look to be on the narrower side, but I would like to try them out as 2 of the guys I ride with love them.


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## joecx (Aug 17, 2013)

*OneSpeed* said:


> OK, fair enough, I tried.
> 
> At least now I know you can't comprehend a single thing I've written in this thread, have ignored the most significant points, and choose to be jerk about it when I was trying to get specific and help (without being rude).
> 
> You've completely ignored the most relevant parts of the geometry discussion and focused on attacking me personally.


Will you just get over yourself and shut up!


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## Fuse6F (Jul 5, 2017)

The OP is absolutely right. Great post and great patience shown while taking the hits from people who are not up to speed! 

so much has been said that I might jump around a bit...

manufacturers are making bikes for the masses. So the sweet spot is the average joe and the bike they are selling, regardless of geometry, is optimized around that rider size. 

a mountain bike must change all the frame components between sizes. Otherwise bike performance will be different between sizes. This is a fact.

at 6’6” and 260lbs. I don’t get quite the same performance on my bike as a 120lb size small rider. It’s just not physically possible. same tubing and frame strength, same wheel strength, just pulling up on the bars they flex different.

Pole makes a pretty advanced bike. Why the super long chain stays. They have super steep seat tubes too. Super slack front end. Guess it rides like a dump truck!!! I just don’t want to pedal it on a 30 mile moderate mostly flat trail ride. It’s made for going straight up and straight down.

the fad is to shuttle and ride parks. Bike design is now reflecting that. 


now sta. So much crap on here. Effective sta as measured through the bb. Okay sure... but what about at seat height as needed by riders of different leg sizes. The trend is to put super short seat tubes now so that short legged riders can ride a size up and still touch the pedals using dropper posts. Taller riders can just use a longer dropper. But where will they sit when all is said and done. Where is the size up for the rider like me who is 6’6” and 39” inseam? 

in a seated position, you use gravity to hold you down so you can press into the pedal to make power. Well the peak power point changes in crank angle as the trail slope changes. if the seat tube doesnt move forward then some of your power gets wasted and it starts to push you backwards off the seat. so you start pulling back on the bars to hold on. that giant rider is also seated on the tip of a triangle ( tire contact patches to seat). the higher you make that triangle the more rearward its going to move as you tip it back. a shorter rider sits down inside the wheelbase alot more. you cant make it all up with a forward seat tube angle as the fore aft movement is just too great for taller riders. think super steep to flats. super tall guys actually want super steep sta on the climbs but much slacker on the flats. otherwise we are knee compromised. either cant climb or have knee pain on the flats (think 30miles twice a week with you knee too far forward) im suprised that we dont have a top tube dropper post to allow dynamic variation in sta as trail dictates


chainstays absolutely affect front rear weight bias. but how much? the changes are small but positive on a climb and mostly zero on downs. i think it affects the flat turns most. personally, telling someone to move more weight onto their hands is crap. why would i want to move weight from my feet (below the center of gravity) up high and onto the bars.

i get it that a short rear end makes it easier to get the front end up. but tall riders have more rearward weight movement from body position period. we can afford another 25mm. so why not give it to us. wheres the downside? 

IMO, manufacturers simply dont want to spend the money developing and producing a new rear design. leverage ratio changes, valving changes, material strength changes.


the dynamics of mtb riding are infinitely variable and further complicated by different rider sizes. hell, just take the same trail but mud day vs hardpack day. we all see the differences in performance between tires.

its pretty clear to me that super tall riders get the majority of compromises regarding frame design and geometry.


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## Fuse6F (Jul 5, 2017)

hta angles are kinda scary.... i took slow motion video this spring riding my stumpy w yari in the parking lot. you can see the abundant flex as the wheel came down after lifting the front to clear just the curb. can you imagine what a 62 degree head angle and landing flat would do to a single crown fork with my 260lbs.


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## Suns_PSD (Dec 13, 2013)

Sure but that assumes every compression event is in the vertical plane. But when trail riding most impacts come at you a lot more horizontal. 
With so many bikes available, I feel that even really large people can find a bike that works well for them, you just can't choose from any old bike. But the Megatrail for instance is an overly stiff frame for more typical riders and can go up to 445mm chainstays, and an XXL size, desirable traits for physically large riders. 
When I shopped for a bike for my wife I considered these things carefully. As she is tiny I choose a bike known to be flexy/ compliant, adjustable short CS, and not overly steep STA.
Due to motorcycles, sports cars, and bikes, I'm glad that I'm right in the fat part of the bell curve for males, but there are solutions for those outside of it.

Sent from my SM-G892A using Tapatalk


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## Jwiffle (Jan 26, 2004)

alexbn921 said:


> Longer stays = a more planted front end on climbs. Good
> Longer stays = better balance and allow an even longer front. Good
> 74-75 degree STA = better pedaling position for me. Good


Yet my new bike has 0.75 inch shorter stays than my old bike, and the front end stays planted better on climbs than my old bike.

Of course, my new bike does have a longer front end than my old, too. So I get a win- win: long front to keep the front planned on climbs, short rear to keep handling snappy and playful.

75-77 degree STA = better pedaling position for me. Good. I can the seat be neutral instead of all the way forward on the rails. I can sit on the seat instead of the nose on climbs.

Obviously, what works for you works for you. But the new geometry works much better for a great many of us.


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## alexbn921 (Mar 31, 2009)




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## Fuse6F (Jul 5, 2017)

Suns_PSD said:


> Sure but that assumes every compression event is in the vertical plane. But when trail riding most impacts come at you a lot more horizontal.
> With so many bikes available, I feel that even really large people can find a bike that works well for them, you just can't choose from any old bike. But the Megatrail for instance is an overly stiff frame for more typical riders and can go up to 445mm chainstays, and an XXL size,  desirable traits for physically large riders.
> When I shopped for a bike for my wife I considered these things carefully. As she is tiny I choose a bike known to be flexy/ compliant, adjustable short CS, and not overly steep STA.
> Due to motorcycles, sports cars, and bikes, I'm glad that I'm right in the fat part of the bell curve for males, but there are solutions for those outside of it.
> ...


my 100lb wife rides a norco fluid ht xs frame and has 26" plus tires as that frame size performance was optimized for a smaller wheel.

tall guys are super happy that 29ers came out. but i roll my eyes when i see 5'6" 145lb xc pro racers riding them. they have 80mm headtubes and massive negative stems to get proper bike fits to compete on. could i get a set of 36" wheels please so i can setup my fit the same.

bike designs exist for larger riders but they tend to top out around 6'2" top out!!! beyond that another frame size is needed. if a guy 5'10" is riding 500mm reach. shouldnt i be on 560. where are my 32" wheel bikes.

the only bike on the market that im looking at next is a sc hightower and if you look at the geo charts they set it up w massive stack, reach and even longer chainstays!!! doesnt change the fact that id like that frame option w a bit steeper headtube and slightly slacker seat tube. but thats for my riding and trail preferences. but shorter guys have that option.

i feel that xxlarge sized options dont provide more specific fit optimization and there are very few choices across the genre so we dont get to make the same frame choices that regular sized riders can.

fork flex.... are you willing to ride your same bike w 30mm fork tubes.... why the hell not? for the same reasons i would like much stronger frame and stronger crown assemblies. hey... they have e bike brakes out now for the extra weight of the e bikes. i have 80lbs on the average rider. didnt know ebikes were more than 80lbs heavier than regular bikes... guess they werent needed! fox makes e bike forks where the 34mm is really 32mm internals as they thickened the internal tube walls making it necessary to run the downsized damper internals.

no one seems to understand the concept of being oversized for a frame. because they are not oversized so they just dont know what it feels like. why should they waste their time thinking about it either. life is complicated enough. but its funny how many people waste their time telling us why we are wrong for knowing what we already know.


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## Suns_PSD (Dec 13, 2013)

Well of course bigger guys don't have as many options, that's the nature of capitalism. 
But the point is that you do in fact have options. You can even have a bike custom built for instance. Install a double crown fork, and so on. 
As far as wheel size is concerned, I don't see that changing in your favor for a long while, not enough demand. However I do expect that we'll see a larger wheel option up front in time. Going to be really hard to stabilize that thing under a big guy. Really going to need a very strong set up.

Sent from my SM-G892A using Tapatalk


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## Vespasianus (Apr 9, 2008)

alexbn921 said:


> Go on the road bike forums. They hate thru axles and disk brakes.


For the most part, they are over-kill and just added weight (for road bikes).

What is amazing in the road bike world is the resurgence (if it ever left) of high end custom steel and the move away from carbon.

I would also say, all this talk about seat and HT angles is interesting from a road bike point of view as there are lots of data on the impact of extreme ST angles on knee pain and the such.


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## Smackem (Sep 2, 2019)

So long as Nicolai and Pole continue to make mountain bikes, there will always be bikes for large riders.

If your weight is busting past 200 lbs, that is an issue that has nothing to do with geometry.

Bikes are built on a bell curve, if you’re in the middle plenty of options.


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## J.B. Weld (Aug 13, 2012)

Vespasianus said:


> For the most part, they are over-kill and just added weight (for road bikes)


Disagree. If you ride in mountains with long, steep descents discs have superior performance and inspire more confidence than rim brakes. Also far better in the wet though I admit I rarely venture out in inclement whether.

I'm not really seeing a move away from carbon either but agree steel will never go away.

Another (mostly) unsung advantage of disc brakes is that rims can be designed to be stronger and lighter than equivalent rim brake ones


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## Schulze (Feb 21, 2007)

*OneSpeed* said:


> It's odd that you are asking for a more slack STA, then complain that the front end gets light on steep climbs because your weight is higher and too far back. This is an example of where you contradict yourself. Slightly longer chainstays may help, but


I laughed out loud when I read this. You think longer chainstays *may* help?



*OneSpeed* said:


> I don't think you understand what you're asking for.


uh huh.


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## *OneSpeed* (Oct 18, 2013)

Schulze said:


> I laughed out loud when I read this. You think longer chainstays *may* help?


Feel free to substitute the word "would" in that sentence if it's helps you grasp what I was saying there. I didn't mean it as "might".


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## Vespasianus (Apr 9, 2008)

J.B. Weld said:


> Disagree. If you ride in mountains with long, steep descents discs have superior performance and inspire more confidence than rim brakes. Also far better in the wet though I admit I rarely venture out in inclement whether.
> 
> I'm not really seeing a move away from carbon either but agree steel will never go away.
> 
> Another (mostly) unsung advantage of disc brakes is that rims can be designed to be stronger and lighter than equivalent rim brake ones


I would argue that the number of people riding long steep mountains are few and even fewer are those that do them in inclement weather. And the number of roadies that can actually descend worth crap even fewer.

With that said, I think caliper road bikes are going away. The simple punter wants discs. So he/she will get discs.

For the mass market, carbon still rules. But for the high end crowd (around me), everybody is riding high end steel/carbon mixed bikes.

Also, I always thought that the dogma was that steep ST angels are great for time trials and tri's but are associated with knee pain for long term use.

I wonder if the type of pedals people use (clip or flat), the length of rides, the amount of climbing, etc all is impacting how people deal with steep ST angles on MTBs.


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## J.B. Weld (Aug 13, 2012)

Vespasianus said:


> I would argue that the number of people riding long steep mountains are few and even fewer are those that do them in inclement weather. And the number of roadies that can actually descend worth crap even fewer.


I can't be the only one who lives in a mountain town, long climbs and descents are about my only option for road rides.

Imo discs are better for road for the same reasons that they're better for mountain. The weight difference is only a few grams so why not?


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## BmanInTheD (Sep 19, 2014)

This thread kinda got derailed but oh well. After riding disc brakes on road bikes for the last few years, it's beyond me why people would still choose rim brakes. The weight difference is not that great and the discs perform (and feel!) much better, and I live in a flat area. Roadies are much more entrenched in their habits (think ski racers who said they'd NEVER use short, parabolic skis) than mountain bikers, this is why the cling to their crappy-ass rim brakes.


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## Fuse6F (Jul 5, 2017)

Smackem said:


> So long as Nicolai and Pole continue to make mountain bikes, there will always be bikes for large riders.
> 
> If your weight is busting past 200 lbs, that is an issue that has nothing to do with geometry.
> 
> Bikes are built on a bell curve, if you're in the middle plenty of options.


Every bike i get on is way too small. Not enough top tube usually and the knees are way past the spindles at seat height. This should be worse for bikes with steeper STA's.

But you got me thinking about the Pole bikes. I remember from previous glances that their seat tube is straight through the bb (similar to my fuse).

The way i currently have my xxl Stumpy configured, i think/feel the XL Pole would be too small. There would not be enough stack or top tube length.


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## Le Duke (Mar 23, 2009)

Disc brakes are the best upgrade I’ve ever made to a road or CX bike. Followed closely by wider, more comfortable tires. 26 or 28mm tires on a 21-23mm internal rim? Yes please. 

Simply amazing. 

I’d say that more than half of the local P/1/2 crowd is on disc brakes. Maybe 2/3rds. 


Sent from my iPhone using Tapatalk


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## alexbn921 (Mar 31, 2009)

Just built this bike from the frame up 4 months ago. Disks brakes and big tubeless tires are so much better. XXL 61cm.


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## Jwiffle (Jan 26, 2004)

Fuse6F said:


> Every bike i get on is way too small. Not enough top tube usually and the knees are way past the spindles at seat height. This should be worse for bikes with steeper STA's.
> 
> But you got me thinking about the Pole bikes. I remember from previous glances that their seat tube is straight through the bb (similar to my fuse).
> 
> The way i currently have my xxl Stumpy configured, i think/feel the XL Pole would be too small. There would not be enough stack or top tube length.


If you're really tall, you should probably use longer than standard cranks. That would bring your knees more in line with the spindles, too.


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## alexbn921 (Mar 31, 2009)

Jwiffle said:


> If you're really tall, you should probably use longer than standard cranks. That would bring your knees more in line with the spindles, too.


Your right, but cranks are harder to find past 175mm and most BB heights are not raised on XXL bikes to accommodate the extra clearance needed.

If you put a 185mm crank on a modern bike, pedal strikes would make it unridable.


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## isleblue65 (Sep 5, 2009)

alexbn921 said:


> Your right, but cranks are harder to find past 175mm and most BB heights are not raised on XXL bikes to accommodate the extra clearance needed.
> 
> If you put a 185mm crank on a modern bike, pedal strikes would make it unridable.


True, I ordered 165mm cranks for my Ripmo due to pedal strikes with the standard 175mm cranks with my XL frame, but thought twice about that due to being 6'4" tall with 36" inseam. I ended up increasing my DPX2 shock pressure to reduce sag, and increasing fork travel from 160 to 170mm. Between that and learning to clock the cranks and backpedal on occasion to avoid rocks, I've figured it out. On my Niner Jet 9, I could ride over or past the same rocks that the Ripmo pedal strikes hard, so this was an adjustment.

Sent from my iPhone using Tapatalk


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## scottzg (Sep 27, 2006)

isleblue65 said:


> True, I ordered 165mm cranks for my Ripmo due to pedal strikes with the standard 175mm cranks with my XL frame, but thought twice about that due to being 6'4" tall with 36" inseam. I ended up increasing my DPX2 shock pressure to reduce sag, and increasing fork travel from 160 to 170mm. Between that and learning to clock the cranks and backpedal on occasion to avoid rocks, I've figured it out. On my Niner Jet 9, I could ride over or past the same rocks that the Ripmo pedal strikes hard, so this was an adjustment.
> 
> Sent from my iPhone using Tapatalk


Same inseam- i barely notice 165mm cranks. I don't prefer them and wouldn't choose them for a road bike, but they're a great alternative for my mtb. My impression is that excessively long cranks is abruptly a huge problem, but shorter than optimal is subtle until you start getting really fkn short. Since BB height and crank length are mutual tradeoffs, it's really grey how long our cranks should be.

If you're bashing your pedals 165 cranks might be the best solution even for us tall folk. :thumbsup:


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## Fuse6F (Jul 5, 2017)

on my fuse hardtail i didnt know what a pedal strike was.

on my xxl stumpy i installed 175mm cranks to get the knee in better alignment. then i learned i could strike the ground pedalling across my lawn. seriously i had ten to twenty strikes a ride. 


offset shock bushing, max shock pressure and max spacers later i still smack the ground on a regular basis. 

ive learned to be smoother and to ride like spiderman tossing the bike side to side just to gain clearance for the foot coming down next.

338mm bbh
175mm crank
30% sag on a 135mm rear end is approx 40mm
pedal thickness is 18mm so half of it

lsum is about 225mm or 338-225=113mm clearance still have some suspension movement pedalling so half that again and we are left w about 55mm clearnce 

best hope we dont have a 2” bump on the trail or its a pedal strike!


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## Fuse6F (Jul 5, 2017)

looked at the pole geometry and did some drawings to see where the sta would put my knee at horizontal and 40 degrees up from horizontal.

used the same measurements and method on my stumpy. 

result: front of knee is 30mm forward on the pole due to the seat tube being further forward (steeper sta)

long xc rides make the knees sore on the stumpy

cant see how riding the pole w the front of the knees another 30mm further ahead is going to make my knees better. but will definitely climb better!

i might do same calcs for a typical rider say 5’8” someone who might ride a medium just to see the diff in knee placement.

anyone want to volunteer their dimensions?

center of rotation of hip to floor, then hip to center of rotation of the knee, height of ankle to the floor and the horizontal distance from ankle center to the spindle under the foot.

take measurements without shoes and within reason for accuracy.


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## Fuse6F (Jul 5, 2017)

im curious about super short cranks. i know it will help w bb stikes, but it would raise my center of gravity (a negative for climbing) the curious part is that it will cause less total angular movement in the knee.

does anyone have data or experience on this?


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## Smackem (Sep 2, 2019)

Fuse6F said:


> im curious about super short cranks. i know it will help w bb stikes, but it would raise my center of gravity (a negative for climbing) the curious part is that it will cause less total angular movement in the knee.
> 
> does anyone have data or experience on this?


YouTube it. The info is true. I personally run 160 road cranks, and would run 160 mountain if they were more available.


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## Schulze (Feb 21, 2007)

I bought half a dozen offset bushings a year ago to tune my bb heights. If frame manuf left some adjustability in their shock mounts and used ZS headsets so anglesets would fit (or designed the head tube for hta mods) bikes would be a little more customizable. Yes, I saw the NS bikes post on Pinkbike, not a bad effort.


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## LMN (Sep 8, 2007)

Geometry is not a one size fits all.

Steep seat angles and short chain stays are absolutely amazing in some areas and terrible in others. Picking the bike that suits your riding area, and the area of your riding where you care about maximum performance is critical.

What do steep seat angles give you? On a steep climb on a long travel bike they put you in a classic pedalling position. This means that your knee is approximately over the pedals and you have a reasonable weight distribution on the bike. Unfortunately that same position puts you quite far forward on low grade trails and might actually be quite uncomfortable. If you live in a place where the bulk of your climbing is super steep (Whistler for example) then a super steep seat angle is really nice. If you climbs are low grade (Moab, Sedona for example) then that position isn't ideal.'

What do short chain stays give you? Mainly they make it is easier to get the front end in the air. For steep rolls and drop this really nice, but they make the bike less stable. Slow speed techy trails are pretty nice with short chainstays, but they can be a handful on high speed trails with sweeping turns.

Personally, I am little mixed on the super steep seat angles. I do like them for steep climbs but I find it makes the bike less comfortable everywhere else. The year I am running an XC bike with a 75 degree angle and for the first time ever I struggled with sore wrists on long days in the saddle. Short chain stays on the other hand are sweet. Just about every change we have done to bikes recently has increased stability and made it harder to loft the front end, something reversing that trend is nice.


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## alexbn921 (Mar 31, 2009)

Fastest Known Time on Moab's White Rim Trail





Bike trek top fuel with a 75.5 STA and a setback post.

Of course it's already been beat by an 18 year old.


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## rynomx785 (Jul 16, 2018)

alexbn921 said:


> Fastest Known Time on Moab's White Rim Trail
> 
> 
> 
> ...


 Looks like mainly graded dirt road and none of the climbs looked overly steep? Not really a ride that modern trail/enduro bikes are aimed at.


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## alexbn921 (Mar 31, 2009)

rynomx785 said:


> Looks like mainly graded dirt road and none of the climbs looked overly steep? Not really a ride that modern trail/enduro bikes are aimed at.


The climbs are challenging and steep, but I agree that it is not an enduro trail or bike. My point was more that top athletes are picking slacker STA when putting out power and spending time on the bike are key.


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## EatsDirt (Jan 20, 2014)

rynomx785 said:


> Looks like mainly graded dirt road and none of the climbs looked overly steep? Not really a ride that modern trail/enduro bikes are aimed at.


Agree.

Mesa riding is undulating, and add in short travel and a steep STA isn't as beneficial - for me.


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## Le Duke (Mar 23, 2009)

rynomx785 said:


> Looks like mainly graded dirt road and none of the climbs looked overly steep? Not really a ride that modern trail/enduro bikes are aimed at.


I rarely see "enduro" bikes climbing anything OTHER than dirt roads.

Sent from my iPhone using Tapatalk


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## rynomx785 (Jul 16, 2018)

Le Duke said:


> I rarely see "enduro" bikes climbing anything OTHER than dirt roads.
> 
> Sent from my iPhone using Tapatalk


No idea where you are and that seems to be a pretty common thing in lots of places that have an access road to the top but I ride my "enduro" bike (Ibis HD4) on a lot of trails that do have steep single track climbs. My biggest complaint is the front end getting light. I have learned to drop my seat post a little and get forward to compensate but it sure would be nice to have the STA steeper. It may effect my power output on flat ground but I didn't get this bike to ride on flat ground so it is not a concern of mine.


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## DarknutMike (Jun 2, 2013)

Not a fan of most of the current bikes out there. For one thing to say I'm not a fan of 29'ers is putting it mildly ... I can't stand them & that seems to be the current fanboy fav. I have test ridden many 29'ers & I can't stand how they feel. I'm a huge fan of Transition bike company but the current batch with steep SA way slack HA & too long top tubes not so much. I will stick with my 2014 Covert 26 ... most fun bike ever IMHO. I bought a spare just in case.


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## Carl Mega (Jan 17, 2004)

Le Duke said:


> I rarely see "enduro" bikes climbing anything OTHER than dirt roads.


That feels confusing coming from a Front Ranger. What are the FR dirt road climbs? I'd expect that there are plenty of enduro bikes riding the exact same JeffCo trails that everyone else does.


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## evasive (Feb 18, 2005)

Le Duke said:


> I rarely see "enduro" bikes climbing anything OTHER than dirt roads.
> 
> Sent from my iPhone using Tapatalk


This is necessarily location-dependent. It requires lots of upper trailheads accessible via dirt roads. I'd always rather climb singletrack, and that's mostly what we have here. There's no shortage of riders climbing the trails with enduro/AM bikes.


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## cookieMonster (Feb 23, 2004)

evasive said:


> This is necessarily location-dependent. It requires lots of upper trailheads accessible via dirt roads. I'd always rather climb singletrack, and that's mostly what we have here. There's no shortage of riders climbing the trails with enduro/AM bikes.


Yep. I'm in Montana too. I'd like to know where the fire road climbs are, because it might be nice to get a break from the usual 2k' singletrack climbs in less than 3 miles, for a change.

On the flipside, one of my favorite rides in my neck of the woods can be climbed via the singletrack as an up and back, or there's an old logging road to the top. 99% of the time I take the singletrack; as it is much more interesting and challenging.


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## cookieMonster (Feb 23, 2004)

DarknutMike said:


> Not a fan of most of the current bikes out there. For one thing to say I'm not a fan of 29'ers is putting it mildly ... I can't stand them & that seems to be the current fanboy fav. I have test ridden many 29'ers & I can't stand how they feel. I'm a huge fan of Transition bike company but the current batch with steep SA way slack HA & too long top tubes not so much. I will stick with my 2014 Covert 26 ... most fun bike ever IMHO. I bought a spare just in case.


I was a naysayer too, until I bought one and rode it for a few weeks. For long travel, gnarly terrain riding, I still prefer 27.5" wheels and big tires for their playfullness and agility.

But this new crop of light travel but aggressive geometry 29ers are something else.

My 29" bike is a hardtail and I am amazed at how much it _doesn't_ beat me up compared to my old hardtails. And more often than not, I am keeping up, if not beating the times of those that are overbiked on modern enduro rigs. It takes a really steep and gnarly trail in order for my enduro bike to actually be faster overall.


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## TimTucker (Nov 9, 2011)

Fuse6F said:


> im curious about super short cranks. i know it will help w bb stikes, but it would raise my center of gravity (a negative for climbing) the curious part is that it will cause less total angular movement in the knee.
> 
> does anyone have data or experience on this?


I'm around 5'11" and have switched to 152/155mm cranks on all my bikes now. Lots of options out there for shorter cranks, but you have to know where to look (Trailcraft is one of the popular choices in the Families & Riding with Kids forum).

It's nice for avoiding pedal strikes and does lead to a slightly higher seat height -- in theory that would leave me room to run a longer dropper.

Haven't noticed any issues with the cranks and climbing, but I'm commonly pulling my son via a TowWhee on climbs, which creates its own set of challenges for stability:
https://towwhee.com/

I also run a Nexride noseless saddle on top of a Rinsten spring clone on top of a dropper post -- I'm not really sure what my effective seat angle winds up with all that attached, but I think it's a bit steeper than stock (along with a 40mm stem and 80mm bars, it's probably closer to modern geometry than the bike started out):








For reference, here's a link to the saddle springs off Amazon (I got mine from Aliexpress, but they're all mostly the same) -- on a hardtail, they help soften the ride and give you additional fore / aft saddle adjustment:
https://smile.amazon.com/dp/B07CVY5ZXS/

Similar setup on my '92 Trek 830, which is even more off from the original specs (90mm shockstop stem / 800mm bars / bar ends inboard of Ergon grips):


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## chasejj (Sep 22, 2008)

Came off of 20 years of Turners which for the most part stick with steeper HTA and moderate STA , his philosophy. Except a custom one I convinced him to make which was long TT and slacker HTA . Which was awesome but broke after 2 years of thrashing it. Tried talking him into longer Front Centers and steeper STA frames but he was having none of it. So I bought a GG TP. Which has been amazing in opening my eyes to steep STA and kind of slack HTA and very long FC. I have a new Banshee Titan coming on Thursday which is a little longer FC, slacker HTA , slightly steeper STA and has much longer chainstays which one of the great features the DW Turners had (long chainstays). The CG centered between the wheels has been and always will be the issue. Chris Porter talks about this non stop and I agree with him. Although the cost of his bikes is not in my budget right now. Pole needs to have varied chainstays for each size to truly match Geometron. Norco and Banshee have really caught onto something with varying lengths of CS on their recent version.
Big guys have been getting hosed on frame designs for years as a single CS length provides much better CG balance on the smaller frames than the larger frames as you increase the size. 

I am 6-3 and run 175mm cranks and slide way up the saddle nose on my GG to keep front down (even at a 75+ STA) . I feel it could use a steeper STA even though my knees definitely move forward of the pedal spindle. It allows a better spin motion for more even power transfer than pushing forward and pumping against the back of seat. 
I think the next phase of progression could be linkage front ends and steeper HTA to take advantage of constant trail designs.


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## *OneSpeed* (Oct 18, 2013)

chasejj said:


> Came off of 20 years of Turners which for the most part stick with steeper HTA and moderate STA , his philosophy. Except a custom one I convinced him to make which was long TT and slacker HTA . Which was awesome but broke after 2 years of thrashing it. Tried talking him into longer Front Centers and steeper STA frames but he was having none of it. So I bought a GG TP. Which has been amazing in opening my eyes to steep STA and kind of slack HTA and very long FC. I have a new Banshee Titan coming on Thursday which is a little longer FC, slacker HTA , slightly steeper STA and has much longer chainstays which one of the great features the DW Turners had (long chainstays). The CG centered between the wheels has been and always will be the issue. Chris Porter talks about this non stop and I agree with him. Although the cost of his bikes is not in my budget right now. Pole needs to have varied chainstays for each size to truly match Geometron. Norco and Banshee have really caught onto something with varying lengths of CS on their recent version.
> Big guys have been getting hosed on frame designs for years as a single CS length provides much better CG balance on the smaller frames than the larger frames as you increase the size.
> 
> I am 6-3 and run 175mm cranks and slide way up the saddle nose on my GG to keep front down (even at a 75+ STA) . I feel it could use a steeper STA even though my knees definitely move forward of the pedal spindle. It allows a better spin motion for more even power transfer than pushing forward and pumping against the back of seat.
> I think the next phase of progression could be linkage front ends and steeper HTA to take advantage of constant trail designs.


Interesting, good comparisons. (Sad but interesting info about Turner.)

Some of the longer chainstay preference I feel is very specific to the region and local trails, but certainly not all. Some of that also has to do with rider height and frame size, but certainly not all. IMO most of it boils down to personal preference, skill level, fitness, and riding style. Almost none of which is quantified in online opinions, which are free.

I agree on STA, on my modern mid travel trail bike the STA is 76.2 and I have the saddle all the way forward. I also have much shorter chainstays than you seem to prefer at 427mm (I'm also 6'3" and ride an XL BTW) but I'm also on the East Coast and ride tight trails with punchy ups and downs with lots of trees.

Anyway, I like your post and I think it's one of the better commentaries in this thread. Lots of good info and interesting experience/comparisons.


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## RadBartTaylor (Dec 1, 2004)

I've NEVER understood why people insist on comparing MTB fit to road fit. KOPS is worthless in a garage or on a stationary bike fit setup as it doesn't take into account (2) key differences:

1) Steepness of hills - obviously road bikes are ridden on much shallower grades. You'd need to jack up the front of the MTB before if fitting on level ground to compensate.

2) Suspension sag for FS bikes - this needs to be taken into consideration and I'd argue going uphill under power, it's more than the static rider sag # the manuf recommends by a good %.

Account for those two things and I bet STA's need to be 77+ deg to be comparative.

A few years back I got into a discussion with some folks on here about pushing saddles forward. I went into the garage, jacked up the front of the bike to a modest grade, let air out of the shock to replicate rider sag and it more than DOUBLED my saddle setback. It was at 100mm (per road bike fit) and increased to 200mm+. I couldn't adjust for that with my Cannondales low 60 deg STA even with saddle forward.

So obviously, put me in the steep STA camp without a doubt. I'm 6-4 with 37" inseam and have always had issues with the front staying planted without killing myself trying to stay up on the front of the saddle using upper body strength. My new winter bike, a Banshee Paradox hardtail, XL, is awesome....even with a 150 fork.


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## Entrenador (Oct 8, 2004)

*OneSpeed* said:


> And if I were running the company they would all be steel SS 29ers, and the cycling world would be a much more boring place.


Blasphemy! SS hardtails make every trail more interesting!


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## Entrenador (Oct 8, 2004)

In some combination, improvements in brakes and suspension led to more capable bikes - specifically, bikes capable of descending faster, tougher terrain. Dropper posts accelerated this shift towards greater descending capability.

I say this merely to point out the general lack of acknowledgement of how not just geometry, but trails and riding styles have changed. I'm riding far faster and with more confidence on my "progressive" (by 2015 standards) hardtail than I ever did on my last FS bike, and this is a testament to the elevated potential that came with geometric and technological changes (brakes, suspension, dropper).

So I pose a few questions for those of us who have been riding trails for more than 15 years, and have replaced bikes successively with more progressive ones:

1) Are you riding the same trails or have your tastes changed?
2) Are you generally in the saddle as often when climbing? On flats?


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## CrozCountry (Mar 18, 2011)

Since the first time I mountain biked I had a problem of the frames too short (length), the seat too far back, and the seat tubes too long. So I ended up next frame size up, which made the seat tube even worse. I almost never had fit issues with motorcycles, always with bikes.

After many years they finally make frames sized for an average human body. I thought I am special, but apparently I am just average  Let me enjoy it while it lasts.



mack_turtle said:


> The "push up method" for measuring handlebar width is 100% bullshit. It tells you where to put your hands to do a push-up, nothing more. KOPS is also bullshit. That's old news.


The push up method it 100% right if you do push ups on handlebars.


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## Entrenador (Oct 8, 2004)

93EXCivic said:


> I like short chain stays. I mean it isn't the only part of the equation but IMO it helps make a bike feel more fun and I am more then willing to give up a bit of climbing performance for that.


Ditto.


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## chasejj (Sep 22, 2008)

Entrenador said:


> In some combination, improvements in brakes and suspension led to more capable bikes - specifically, bikes capable of descending faster, tougher terrain. Dropper posts accelerated this shift towards greater descending capability.
> 
> I say this merely to point out the general lack of acknowledgement of how not just geometry, but trails and riding styles have changed. I'm riding far faster and with more confidence on my "progressive" (by 2015 standards) hardtail than I ever did on my last FS bike, and this is a testament to the elevated potential that came with geometric and technological changes (brakes, suspension, dropper).
> 
> ...


Do to my knees being generously called a "dumpster fire" I am in the saddle all the way with few exceptions and standing on the downs. Droppers are just as significant as improved suspension and wheels in what I ride. Comfortable terrain matrix has expanded for sure. But I'm a moto racer so not much MTB stuff bothers me.


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## Fuse6F (Jul 5, 2017)

not many here really qualify as being in the extreme bike fit category. so you shorter people have experience that is skewed a bit. 

my inseam is 39”. im 260lb so my cg is pretty high up on the bike and more than a little top heavy. i do not feel the in the bike feeling.

imo
varied cs lengths are a smart idea. why would a smaller rider care if a larger rider has a longer cs. let the manufacturers make them.


ride dynamics
the rider creates a triangle on the bike. front and rear contact patch and the cg.

you can move the tip of the triangle forward, this doesnt increase stability, but biases the stability for climbing. 

if you lower the cg, this will increase stability and climbing 

if you move the back edge of the triangle further outward this will increase stability and climbing.

it makes sense to increase the chain stay lengths for larger riders as they have taller triangles.

i predict we see more of this. its already on the xxl hightower! 


if we used shorter cranks, eg 10mm less, then combined w a lower bbh (10mm less), then added longer chain stays. we would move the cg lower, and widen the base of the triangle at the same time win win. we also reduce the angle the knee passes through during each crank rotation. another win imo.


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## 93EXCivic (Mar 12, 2018)

Fuse6F said:


> if you move the back edge of the triangle further outward this will increase stability and climbing.


Increase seated climbing ability and also assuming you want maximum stability.


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## compositepro (Jun 21, 2007)

https://www.peterverdone.com/im-soooo-rad/

pete sometimes comes up with interesting observations on geometry


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## alexbn921 (Mar 31, 2009)

Entrenador said:


> 1) Are you riding the same trails or have your tastes changed?
> 2) Are you generally in the saddle as often when climbing? On flats?


I got my first mountain bike 26 years ago. It was a yellow giant with thumb shifters and purple logos. It had the Velcro shoulder rest in the main triangle so you could carry it up the steep climbs.

I started with XC and have slowly pushed into more DH. Only when I started going beyond the capability of my XC bikes did I really want more bike. You can only put so many spacers in a a fox 32 with a 203mm rotor down crazy steep hills. Have moved several times, so trails are very different. Zero beginner terrain up or down at my local park, which sucks as I have to drive further away to take my kids out on dirt.

I'm 80% seated and 20% standing while climbing. Only seated on flats.


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## Le Duke (Mar 23, 2009)

Carl Mega said:


> That feels confusing coming from a Front Ranger. What are the FR dirt road climbs? I'd expect that there are plenty of enduro bikes riding the exact same JeffCo trails that everyone else does.


Towers Rd in Fort Collins, and Gold Camp in COS.

I don't regularly ride in JeffCo, so I have no clue what people are doing there.


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## cookieMonster (Feb 23, 2004)

Entrenador said:


> In some combination, improvements in brakes and suspension led to more capable bikes - specifically, bikes capable of descending faster, tougher terrain. Dropper posts accelerated this shift towards greater descending capability.
> 
> I say this merely to point out the general lack of acknowledgement of how not just geometry, but trails and riding styles have changed. I'm riding far faster and with more confidence on my "progressive" (by 2015 standards) hardtail than I ever did on my last FS bike, and this is a testament to the elevated potential that came with geometric and technological changes (brakes, suspension, dropper).
> 
> ...


I've been riding the same trails for at least 23 years, and some from my hometown for 35 years. Loooots of different bikes in that time, obviously.

I feel like mountain bikes really started to become, let's say - intelligently designed- in the early 2000s. At least that's when they started bearing a closer resemblance to modern trends which I think are not going to change a whole lot more, geometry wise.

The first bikes I rode that were edging toward slacker head angles and big travel were very heavy beasts with high front ends and highish bottom brackets. I kept my second Santa Cruz Bullit until about 2010. It had a Marzocchi 66 and an Avalanche rear shock. The suspension quality was superb, even by today's standards. I rode that bike hard, and in fall-line gnar situations, I'm not sure that I'd be any faster today on my more modern bike.

The biggest change, I think, is that the weight of aggressive geometry bikes has come WAY down - and that is where most of the speed increase comes from. And even then, it is mostly felt in the corners, which, as it happens are kind of the emphasis in modern trail building. One thing to note is in the last years I rode my Bullit, I got some modern wide bars with a low rise, and repositioned the stem lower as well. Those modifications alone forced me to get more forward and put more weight on the front end, and once I got used to that my cornering speed improved. Every change can make a difference.

Probably going off on a tangent here but over Thanksgiving I was hiking near my hometown and came across a boulder that I used to approach at about 20mph and then ride all the way to the top of it (about 12 feet off the ground), and then roll off the other side down an insanely steep pitch. I looked at it and just scratched my head. I don't think I'd even try it now, but I did it all the time on my 2000s era bikes. The point is, we can analyze bikes to death but it always comes down to the skill of the rider.


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## bidwellian (Feb 2, 2013)

Jwiffle said:


> I'm fairly tall, about 6'1". I like the new geometry.


I'm 5'8 and don't like the new GEO or wheels sizes...It's made for tall riders. People are getting taller every generation so it was a probably smart move to make all bikes huge, but...

They stopped making bikes that fit me around 2012. I'm glad there's eBay.

I'm riding:

1998 Specialized Stumpjumper M2
(Geo works with riser handlebars)

2011 Santa Cruz Blur XC

:thumbsup:


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## rynomx785 (Jul 16, 2018)

bidwellian said:


> I'm 5'8 and don't like the new GEO or wheels sizes...It's made for tall riders. People are getting taller every generation so it was a probably smart move to make all bikes huge, but...
> 
> They stopped making bikes that fit me around 2012. I'm glad there's eBay.


What reach/stack/wheel base "fits" you?

I am 177 cm tall and I have had 3 bikes in the last couple years. A medium Canyon Spectral with a reach of 436 mm and a wheel base of 1180, a Large Ibis HD4 with a reach of 455 and a wheel base of 1218, and most recently a large Transition Sentinel with a reach of 475 and wheel base of 1247.Each change had me a little concerned with whether or not I had gone too big but in the end, I am super happy with the longer reach of the latest generation of bikes. I didn't list stack because that super adjustable and pretty easy for just about anyone to get it where they want it.

Have you spent some time on a modern bike and given yourself a chance to get used to it?

Sorry, for the thread drift. I know bidwellian and I are short and us short folk aren't really included in the topic at hand here but I have been silently following along because I thought it was interesting and I am super happy with the "new gen geo" of my Transition.


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## Forest Rider (Oct 29, 2018)

bidwellian said:


> I'm 5'8 and don't like the new GEO or wheels sizes...It's made for tall riders. People are getting taller every generation so it was a probably smart move to make all bikes huge, but...
> 
> They stopped making bikes that fit me around 2012. I'm glad there's eBay.
> 
> ...


Interest -I rode a 2000 Stumpy for many years, around 8 or 9 years. I loved it but I always felt like I wastoo big for it. I rode the crap out of it and was comfortable, but when seeing myself on the bike it looked like I was draped over it. Also at 5'8" I was riding a medium frame.
The bike is still in the garage.

I have a 2016 FSR now and it's an absolute blast and and an amazing fit. I throw the leg over the 2000 model and wonder how I rode that thing so fast. I'm so much faster on the FSR and it's so much more fun. It's all about what we get used to, to a degree. The 2016 is also medium sized.

Last year I added a medium Chameleon. The specs are very similar -however shifted. The chainstay is shorter on the Chameleon making the reach longer. I am comfortable on it but the reach is a bit longer than I'd like. With that said, I can ride it about as fast as the FSR and never feel like I am just holding on for the ride.

Both new bikes are pretty amazing to me -I'd never want to give up my FSR or Chameleon so I could only have the 2000 stumpy.


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## bidwellian (Feb 2, 2013)

I went out to buy a new bike and I tried a lot of 29ers and they all felt too big and heavy to me. (My Stumpjumper is about 25lbs)

I tried a new 5010 at my LBS and I liked the 1x transmission, but it felt big and heavy...I had a hard time bunny-hopping over curbs etc. 

I think the GEO has changed to accommodate the larger wheels. I'm glad most people like the new bikes better. I just don't like them as much.


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## Carl Mega (Jan 17, 2004)

Le Duke said:


> Towers Rd in Fort Collins, and Gold Camp in COS.
> 
> I don't regularly ride in JeffCo, so I have no clue what people are doing there.


I respect that you described your experience, but I'm willing to bet that there are Enduro bike riders climbing up regular trails in the 150 miles between the two fire road climbs you cited.


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## chasejj (Sep 22, 2008)

Fuse6F said:


> hta angles are kinda scary.... i took slow motion video this spring riding my stumpy w yari in the parking lot. you can see the abundant flex as the wheel came down after lifting the front to clear just the curb. can you imagine what a 62 degree head angle and landing flat would do to a single crown fork with my 260lbs.


Double crown forks are coming for Enduro bikes for this very reason. Chris Porter has a Dbl Crown kit the MORC 36 for Fox 36 forks. MRP has the Bartlett fork. 
This addresses the issue until we collectively figure out maybe constant trail forks like the Motion and Trust forks are the way to go so the frames came come back to a steeper HTA.
But the only frames for Enduro I'm aware of that are technically designed to accommodate a Dbl Crown are Geometron/Nicolai. TT and DT thicknesses need to be beefed up to take a sudden stanchion hit.


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## chasejj (Sep 22, 2008)

Fuse6F said:


> my 100lb wife rides a norco fluid ht xs frame and has 26" plus tires as that frame size performance was optimized for a smaller wheel.
> 
> tall guys are super happy that 29ers came out. but i roll my eyes when i see 5'6" 145lb xc pro racers riding them. they have 80mm headtubes and massive negative stems to get proper bike fits to compete on. could i get a set of 36" wheels please so i can setup my fit the same.
> 
> ...


Nicolai/Geometron has what you desire. The biggest drawback to them is the complete lack of water bottle mounts. They will not allow threaded nutserts to be installed on the DT at all. Just strap ons. Forcing you into a body mounted solution to water. This sounds petty, but I will not go back to a back mounted hydration solution without resistance. So I bought an XL Banshee Titan which is sort of a Geometron Lite that allows a bottle and IMO probably a slightly better suspension design.


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## TimTucker (Nov 9, 2011)

Fuse6F said:


> not many here really qualify as being in the extreme bike fit category. so you shorter people have experience that is skewed a bit.
> 
> my inseam is 39". im 260lb so my cg is pretty high up on the bike and more than a little top heavy. i do not feel the in the bike feeling.
> 
> ...


Wouldn't you get much of what you're asking for by putting 152mm cranks and a 27.5 wheelset on a 29er frame?


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## RadBartTaylor (Dec 1, 2004)

chasejj said:


> Double crown forks are coming for Enduro bikes for this very reason. Chris Porter has a Dbl Crown kit the MORC 36 for Fox 36 forks. MRP has the Bartlett fork.
> This addresses the issue until we collectively figure out maybe constant trail forks like the Motion and Trust forks are the way to go so the frames came come back to a steeper HTA.
> But the only frames for Enduro I'm aware of that are technically designed to accommodate a Dbl Crown are Geometron/Nicolai. TT and DT thicknesses need to be beefed up to take a sudden stanchion hit.


I'm fully on the link fork bandwagon and am anxiously anticipating what frame manuf's are going to do to optimize for these forks.

As you say, steeper HTA is one thing but can see them also going with shorter reach, lower stack height and optimizing rear sus to play with the forks.


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## Nevada 29er (Nov 12, 2007)

The answer to the question is depends on where and what you ride, horses for courses.

I'm 6'6" and have a XL Pole Evolink 140, one of the most progressive of new school geometries, and a Kona Honzo, which by today's standards is quite conventional. So which do I like better? Depends on the trail.

The Pole is great if you're climbing straight up and bombing back down. The steep STA puts you in a great climbing position, long stays for seated climbing traction. Then at the top you can drop the seat and make use of the slack HTA and long wheelbase to generate serious speed. That is the key with this type of bike, it needs steeps and speed to come alive. In it's element, it's way faster than comparable travel bikes. I had to run tire inserts or I would flat within minutes on rock trails.

On flatter, rolling or undulating trails, that Pole geo doesn't work so well. The steep STA puts you in a less optimum pedaling position, more pressure on the hands, the seat is in the way so you're constantly moving it up and down. In slow speed technical terrain, the long slack geo gets hung up on rock and is just a chore to maneuver around tight corners and objects.

The Honzo on the other hand, shines in more moderate terrain. It's far more fun to navigate the slow speed tech than the Pole. It doesn't get hung up on stuff, the front wheel comes up easier, and it's more comfortable on the hands, less seat adjustment needed.

Overall for where I live and ride, if I had to pick one bike between the two, it would be the Honzo no question. It does so much very well, with few short comings. OTOH, if you ride bike parks, shuttle laps, enduro, the Pole would be the clear choice.

Again, horses for courses, everything is a trade off, no free lunch, [insert your cliché of choice here..]


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## Fuse6F (Jul 5, 2017)

TimTucker said:


> Wouldn't you get much of what you're asking for by putting 152mm cranks and a 27.5 wheelset on a 29er frame?


i want 36" wheels with a 520mm chainstay, 720mm stack, 720mm top tube, 170mm cranks, and a bbh of 345mm

then id feel in the bike!


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## Fuse6F (Jul 5, 2017)

Nevada 29er said:


> The answer to the question is depends on where and what you ride, horses for courses.
> 
> I'm 6'6" and have a XL Pole Evolink 140, one of the most progressive of new school geometries, and a Kona Honzo, which by today's standards is quite conventional. So which do I like better? Depends on the trail.
> 
> ...


there you go... straight from the horses mouth!


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## RadBartTaylor (Dec 1, 2004)

Nevada 29er said:


> The answer to the question is depends on where and what you ride, horses for courses.
> 
> I'm 6'6" and have a XL Pole Evolink 140, one of the most progressive of new school geometries, and a Kona Honzo, which by today's standards is quite conventional. So which do I like better? Depends on the trail.
> 
> ...


I get what your saying....but a lot of what you are experiencing is due to comparing a HT to a FS bike and a bike with different geometry, no just STA. E.g., 78 STA is not a true 'dynamic' measurement while riding. You need to account for:
1) Sag on the Pole...not a factor on the Honzo
2) Actual vs Effective vs Effective 'at height' STA....the last one is a big deal particularly for a guy your height and when the actual vs effective STA's differ on a frame.

While I agree that the super steep STA's are not the best on flat ground, I have a new Banshee Paradox V3 hardtail with a 66.5 STA and it's a fabulous all arounder. I bet your Pole and my bike have very similar 'dynamic' STA's.


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## CrozCountry (Mar 18, 2011)

bidwellian said:


> I went out to buy a new bike and I tried a lot of 29ers and they all felt too big and heavy to me. (My Stumpjumper is about 25lbs)
> 
> I tried a new 5010 at my LBS and I liked the 1x transmission, but it felt big and heavy...I had a hard time bunny-hopping over curbs etc.
> 
> I think the GEO has changed to accommodate the larger wheels. I'm glad most people like the new bikes better. I just don't like them as much.


5 pounds heavier makes almost no difference in bunny hopping, you are jumping mostly your body weight.

The geo did not change to accomodate bigger wheels. The 5010 is 27" bike and the chainstays are very short, even comparing to old 26" bikes. If anything the new bikes feel smaller because of the lower top tubes (standover) and longer droppers.

I think you are just used to old school geometry and bikes. The changes to the new geo are progress.

My friend is a much shorter than you (5 feet) and rides a 29er. So I can tell you for sure that all the "problems" you see are your perception, and you are missing big time for not getting use the the far better designs we have today.


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## agauna (Oct 26, 2016)

My DB Release Carbon has 420mm chain stays, 66* HA, 73* STA, but wheelbase is only around 1190mm making it super playful on trails. Occasionally I’ll come to a climbing section that requires me to lean forward to keep the front wheel down but that’s no biggie.

As far as cockpit set up, just remember that wide bars and shorter offset forks deaden the front end in turns. That can be somewhat offset by a super short stem though.

What I hate is that every bike review has to tell you “well it’s not the best race bike” when the majority of riders don’t [email protected]%king race! I think bike geo has gone beyond the point of being able to have fun in order to appease the relative minority of riders who want to have the fastest stage times “brah”. 

Now, I do race enduro. I have an enduro specific bike for that, which kills the decents and rips at the bike park but I’ll never take it on normal trails. Not near as fun.


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## SikeMo (Mar 17, 2013)

My opinion is that STA should vary from 73 to 76 from XC to enduro. It's really pretty simple and people are putting way too much emphasis on it. As seat tube gets steeper, chain stays can get shorter as the saddle is farther forward of the rear axle. Does anyone actually stand up on the pedals during climbs? Bye bye seat tube angle. This is another reason that shorter travel bikes for rolling terrain with shorter sustained steep pitches should have a 73-74 degree STA.

Much more important is the distance from the bottom bracket to the handlebars, which has gotten almost zero coverage in this thread. This is essentially the lever arm of the bike. The reach, stack, stem length, and handlebar setback should combine to produce an ideal number that's a percentage of your height. On a small bike (for your size), you'll need a longer stem and vice versa. I've settled on stem lengths between 31mm and 50mm and try to find frames that can make these work.


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## ninjichor (Jul 12, 2018)

Was "tall person" ever defined? What dimensions exactly (person and bike)?

Without such info, it's just opinion. In that case, speak for yourself. Don't go making it a generalization for all tall people.

Some people don't like to admit it, but tiny bike differences do matter, even if your goal is merely to have vague sense of casual fun. Riders can adapt to a wide range of geo, but adapting takes effort. I don't know about others' feelings, but I'm impressed when people do stuff on bikes that do less of the work, because I know it takes a lot of finesse to adapt to such small things, regarding finding traction at the limit of control.

Chainstay length isn't a something that's fit to rider height. It's something that's fit to bike length. Larger sizes grow in front end length, so there's some validity to your statement, but some bikes also grow in front end length through slacker HA and longer fork A2C. There are bike models that nicely balance out the CS length with front end length, such as the Forbidden Druid, Privateer 161, Pole Taival (and maybe some of their other models). Norco has tried this, but they they seem to not scale properly, perhaps just arbitrarily choosing to change CSL by 3mm per size no matter the total WB difference. YT and Santa Cruz are sort of incorporating a version of CS length scaling.

Seat post angle, I'd argue is more about the distance the sitting position is behind the BB. When you stand and pedal, your knees are in front of the pedals. Is standing pedaling inefficient? It would be if you rarely ever train pedaling that way. You simply get efficient at what you repeat. In the case of steepening STA, the closer the seated position is to standing, the more likely some training is shared between the two. Also, there will less weight balance difference between sitting and standing--I've measured 70% weight on the rear while sitting on an old school 74d STA bike, while standing on the same bike resulted in a 55% weight bias on the rear wheel (measured using scales under each wheel). That standing position I used is a comfortable upright one, where I'm bent at the waist. If I instead held a position where my butt is back in a squat-like manner, it's closer to 60% weight bias on the rear.

I'm a little shorter than average (5' 7"). On a short chainstay bike with steep STA, when I stand comfortably upright, I had closer to 60% weight bias. I find that I am much more comfortable riding this short CS steep STA bike at a high level, and feel that the old school bike required more focus, but the challenge to ride it, as well as my more capable bikes, was more rewarding. I ride both about the same speed, but my intensity level is a bit higher on the old school bike. I much prefer the modern bike for everyday riding, since I value not getting myself injured, as I know I have a hard time controlling myself from trying something risky if I'm feeling good, which would be better on a bike that didn't need a lot of effort to adapt to, on top of learning something new. On a long CS bike with 82d STA, I find myself spending maybe 200 miles to adapt to the new position well enough to compare to an old one. The long wheelbase makes it very stable, at a cost of playfulness. From my experience, I get the impression that people should be shopping more based on wheelbase than travel or any other figure, where shorter is more playful and easier to handle (e.g. do bunnyhops and wheelies). I find it convenient that I can eliminate so many options from my list based on how long the CS are, compared to WB, aiming for a bike quiver with a short wheelbase to throw down techniques in some quick sessions and a longer wheelbase for longer sessions with speed-work.

If I were to design a bike for a tall person, I would spec a slack STA only if the the bike's WB was very short, and it'd come with a CS that was short for that WB, like 420mm for a 1170mm WB. As the bike gets longer in WB, the STA would inevitably get steeper, as I try to center the rider position between the wheels. Long WB bikes aren't for everyone, especially if you're forced to used the brakes; I believe the long WB work best in areas where you have long sight lines and are aiming to retain speed by using the brakes less. I wouldn't spec a short CS to combat a long WB or front center, as that would force the rider to weight the front, and I can't imagine how that feels for corners and the high risk of washout or understeering.


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## RadBartTaylor (Dec 1, 2004)

ninjichor said:


> Was "tall person" ever defined? What dimensions exactly (person and bike)?
> 
> Without such info, it's just opinion. In that case, speak for yourself. Don't go making it a generalization for all tall people.
> 
> ...


For a tall person you'd spec slack STA and short chainstays? That won't work well...coming from a tall guy, it would be very unstable on climbs.

I had one and it was a PITA on the steep climbs. Was great on the flats, but that was about it...


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## Nevada 29er (Nov 12, 2007)

RadBartTaylor said:


> I get what your saying....but a lot of what you are experiencing is due to comparing a HT to a FS bike and a bike with different geometry, no just STA. E.g., 78 STA is not a true 'dynamic' measurement while riding. You need to account for:
> 1) Sag on the Pole...not a factor on the Honzo
> 2) Actual vs Effective vs Effective 'at height' STA....the last one is a big deal particularly for a guy your height and when the actual vs effective STA's differ on a frame.
> 
> While I agree that the super steep STA's are not the best on flat ground, I have a new Banshee Paradox V3 hardtail with a 66.5 STA and it's a fabulous all arounder. I bet your Pole and my bike have very similar 'dynamic' STA's.


True, a HT can have a slacker STA because all the sag happens at the front, thus most HTs have slacker STs to get a similar dynamic ST to a FS.

That all said, the Honzo just feels more comfortable for me in general. I feel like the Pole needs more stack, and yes I'm running an inch of spacers and a riser bar. This was a bit surprising to me considering how large the Pole looks on paper.

So the other take away here is the numbers and just numbers, and nothing can replace an actual demo. Unfortunately, there are many bikes that just aren't available to demo, depending where you live. However, it never ceases to amaze me when I demo a bike thinking it will ride a certain way based on the geo, and it ends up riding differently.

TRY BEFORE YOU BUY!!!


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## RadBartTaylor (Dec 1, 2004)

Nevada 29er said:


> True, a HT can have a slacker STA because all the sag happens at the front, thus most HTs have slacker STs to get a similar dynamic ST to a FS.
> 
> That all said, the Honzo just feels more comfortable for me in general. I feel like the Pole needs more stack, and yes I'm running an inch of spacers and a riser bar. This was a bit surprising to me considering how large the Pole looks on paper.
> 
> ...


I think you nailed it TBH


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## ninjichor (Jul 12, 2018)

Slack STA is the one way to fit a tall rider on a short wheelbase bike (1170mm), and get weight centered and a familiar feeling ETT. I'd balance it with a longer stem.

The unstable trait is from the front being too light. It's not a short chainstay by itself that causes that, but a chainstay length that's too short for a given front center or wheelbase. For example, 435mm CS is pretty dialed for a 1225mm WB, but it's too long for a bike with 1150mm WB, and too short for a bike with 1300mm WB. I don't like bikes that have 70+% weight bias when sitting either, but it's a trade off to get a short wheelbase.

Yea, steep STA bikes need more stack height. A slack HA lowers the stack. A longer head tube increases stack, but also reduces reach. Adjusting HA is the route I'd play with.

It's foolish to shop bikes by filtering them by specific HA, STA, CS length, stack height, etc. It all works out if you balance them to other geo figures. STA get steeper with longer wheelbase. CS length should get longer with longer wheelbase, but most manufacturers don't do this, so it's no surprise to me that tall folks gravitate to short travel bikes. A Stumpy FSR ST or Trek Fuel EX in XL are some I'd recommend to tall folk, but wouldn't recommend the same bikes to shorter riders. People who shop this way probably waste a lot of money through trial and error, learning geo the hard way. Trying before you buy is good advice.


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## alexbn921 (Mar 31, 2009)

Very good insight ninjichor.
Since most bikes in XXL and even XL are hard to come by, I have always look at the geo of my current bike and tried to figure out how the changes would affect my position and fit on a new bike. Since every bike including the bike I riding was 40-50mm to short, I had to experiment.

Putting the seat back made it impossible to climb steep grades. Putting a long stem made the handling slow and feel disconnected. Every bike was a compromise that we learn to ride around.

Finally, 3 years ago I was able to get a bike that was the right size for me, an XXL Tallboy 3. No test ride of course, because they don't exist in the wild. It was huge and I loved it. I ended up in the middle of the bike with the seat forward and a 60mm stem. Not all was perfect though. The bike lacked front end grip and I had to change the way I positioned myself on it. Nothing I did seemed to get enough weight on the front wheel and a deep dive into what I could do as a rider and how geometry affects weight balance began. Lower bars, longer stem, short offset fork... nothing made the bike balanced. It was still faster, stiffer and more controlled than my old bike, but was lacking in flater corners.

My next bike was an XL Ripmo and it has longer stays and a steep STA, both of which I wanted. The reach was shorter and the front center was about the same. Ballance was much better and I liked the STA on climbs, but it seemed to place me too forward while seated. 76 deg STA put me at the limit of setback on my seat, while still the most forward I had ever been. The bike is magical, but could still be better for me. Ibis absolutely nailed the DW link and build of the bike.

I see the trend of a steeper STA every generation putting seated position out of range for most riders. I feel that 74-76 is the perfect range for most bikes and a great compromise between climbing, comfort and power output.

Bikes need to be designed as a full system and rear center needs to be matched to front center. There is not a one size fits all setup as there is a vast range of bikes. Longer travel bikes tend to favor stability and should have the longest rear stays. Of course all of the other dimensions are important too, but that is a much more in depth conversation.

Looking forward to what the next generation of bikes will bring to the table both in capabilities and compromises.


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## ninjichor (Jul 12, 2018)

Think of the rider fit as being like a diamond between seat, grips, feet, and shoulders. More recent designs are trading off the wide diamond for a taller one, except the grip side is way too low compared to the seat, leading to a rider's back leaning so far forward that it would be "falling" if the hands weren't helping to hold it up (too much pressure on hands and/or fatigued back on a flat bar bike).

Lee McCormack seems to be a source that simplifies some concepts, with opinion, that some people trust. https://www.leelikesbikes.com/bike-setup-my-lower-back-hurts-when-i-ride.html









- This is what I consider a slack STA (Tallboy V1, 73d). Shouldn't have a lofty front end, due to the short front center and 17.5"/444.5mm CS. This bike's stack height isn't high enough though. The head tube could've been made longer. Ask why the newer one is more capable, and I'd say a large part of it is due to Enduro-geo trickle down and getting the weight bias dialed, plus the adjustable CSL makes it 60/40 weight bias in both L (short CS mode) and XL (long CS mode).

In that link, he goes through the trouble of drawing things out to explain rider fit. Notice the change in grip positioning and how it affects the angle of the back. Raising the grip height helps rider comfort, but there's still compromise remaining in longer travel bikes in XL and XXL with the front center being too long. I think the fix is just steeper HAs, honestly, to help get more weight on the front and raise the grip height naturally and also increase reach (long reach allows for a steeper STA too). With steeper HA, to make the steering feel similar to slack HA (stable), can opt for a shorter fork offset.

There's a lot of unnecessary compromise due to bike manufacturers just extrapolating the other sizes. I wonder if any designers have used some specialized simulation software like what's found at https://www.datumcycles.com/

Anyways, I sympathize with what folks who are far from average height are going through. I wish I could be more personal and share my beliefs. I think the Ripmo is great in L, and Ripmo AF is a little close to Transition's balance, being sorta good between M and L. The further you get from this sweet spot size, the more compromised it feels. The new TB dialed in L. Fuel EX more dialed in XL. Most my XL recommendations are 100mm travel 29ers, like the Blur TR. Then there's the suspension (pedal response and bump response) and chassis (rigidity and springiness tuned to specific forces, strong/heavy aggressive rider vs light unfit cautious rider) to consider.

This is a problem with the bike designer. Not balancing front center length with CS length for proper weight balance, and not balancing out the steeper STA increased height by increasing stack. I wouldn't be surprised to see 700+mm stack height with steeper STA on more smartly designed bikes in size XL or bigger. I was personally okay with a 650mm stack height on my 2013 Enduro 29, despite my shorter than average height. I too have like 40mm of spacers under my stem on a 610mm stack height bike.

Preference and local terrain also comes into play. In my personal experience, a 60/40 (60% rearward) weight bias gives the bike the most natural capability, which I found to have a CSL/WB combo of 415/1150mm, 420/1170, 425/1190, 430/1210, and so on (with 29er wheels). If others want more weight on the front (57/43 or 55/45), such as if they have a defensive riding style where they shift their weight back and fear the front slipping out yet are comfortable skidding the rear, maybe they'll like a shorter WB, such as 430mm CS with 1170mm WB. If others want easy wheelies, manuals, and want their front wheel to more easily pop off of bumps for air time, maybe they want smaller wheels with short CS and longer WB, like a 26 with 420mm CS and 1190mm WB. If sight lines were clear to see the trail a long ways ahead, knowing the trail was groomed to not have any unsuspecting obstacles that I need to be cautious around, I'd opt for a longer wheelbase to feel more stable/comfortable at speed. If there's a focus on flow to maintain momentum to clear things, I'd opt for bigger wheels. If there were a lot of chatter and noise-like bumps, that weren't fun to play with, I'd opt for longer travel. If sight lines were short and I had to opt for quickly reacting to unpredictable obstacles, with a lot of braking and accelerating, I'd opt for a shorter wheelbase, smaller wheels, and shorter travel, especially if the bumps were not sharp edged (roots and weathered rocks). My personal preference is gravitating to a shorter ETT--I used to ride mediums with 600mm, back in my XC bike days (I'm 5' 7"), but now I'm open to 570ish since I was running 35mm stems with 600mm. I feel that I'm able to disconnect myself from the bike a bit better, letting it rotate down steep grades without forcing me to be too forward.


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## BansheeRune (Nov 27, 2011)

There happens to be a real world out there and paper doesn't happen to duplicate that in any way...


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## Fuse6F (Jul 5, 2017)

:madman: Old thread. 


i will just say that we need more tall riders building bikes in order to affect real change.


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## Picard (Apr 5, 2005)

Does steep tube angle helps with descent? 

Sent from my SM-G965W using Tapatalk


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## BushwackerinPA (Aug 10, 2006)

Picard said:


> Does steep tube angle helps with descent?
> 
> Sent from my SM-G965W using Tapatalk


no it would hurt......but its irrelevant with a dropper and there is no reason to ride with out a dropper....


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## Varaxis (Mar 16, 2010)

Picard said:


> Does steep tube angle helps with descent?
> 
> Sent from my SM-G965W using Tapatalk


With a steep STA, the saddle could be lowered more before being in range of the rear tire buzzing it at bottom out.

Having a saddle slammed more out of the way can allow for lower sense of penalty for failure, and a bit more range of motion for the legs.

For those that clamp the saddle for control, it would encourage a more forward/aggro position.

----

Fix for steep STA and short CS: move your feet forward on the pedals. If you normally have the balls of your feet over the pedal axle, then a midfoot stance on pedals would basically extend the CS by perhaps even 60mm, and also move the saddle 60mm further rearward from your feet, which is the equivalent of a 5 degree slacker STA.

Fix for pressure on hands: spread the weight of your upper body better, rather than rely on arms to prop it up. Can carry a lot of that weight by engaging the glutes through rotating the hips forward, which puts that weight into your pedal stroke (need a bit of pedal resistance to make it work, so prob not too helpful for spinners).


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## Fuse6F (Jul 5, 2017)

Varaxis said:


> Fix for steep STA and short CS: move your feet forward on the pedals. If you normally have the balls of your feet over the pedal axle, then a midfoot stance on pedals would basically extend the CS by perhaps even 60mm, and also move the saddle 60mm further rearward from your feet, which is the equivalent of a 5 degree slacker STA.
> 
> Fix for pressure on hands: spread the weight of your upper body better, rather than rely on arms to prop it up. Can carry a lot of that weight by engaging the glutes through rotating the hips forward, which puts that weight into your pedal stroke (need a bit of pedal resistance to make it work, so prob not too helpful for spinners).


If your knee was/is over the pedal spindle, as common w steep sta, then

a midfoot position slightly straightens the leg. This reduces pressure on the patella tendon. The knee is also just slightly lower If the leg is straighter. This may allow the upper body to rotate forward slightly more. A more forward cg improves climbing.

the decreased knee angle will allow more downward Pedal pressure with less rearward pressure and thus less pulling on the bars. This may improve your climbing. Your climbing will also be more efficient.

so a midfoot pedalling position can compensate/optimize your pedal dynamics for a given bike fit/geometry.


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