# Bike weight vs geometry vs suspension design



## Bikeventures (Jul 21, 2014)

A lot of new bikes with modern geometry are weighing in 30+ pounds now. The industry is now emphasizing seat angle as the key to helping the bike climb well.

So how much would seat angle compensate in terms of perceived effort?

My current bike is around 30 lbs and has slack seat angle ( < 73 deg ). Would a 32-33 pound with a 76-77 degree seat angle feel easier to climb? Assuming everything else is equal.


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## *OneSpeed* (Oct 18, 2013)

Bikeventures said:


> A lot of new bikes with modern geometry are weighing in 30+ pounds now. The industry is now emphasizing seat angle as the key to helping the bike climb well.
> 
> So how much would seat angle compensate in terms of perceived effort?
> 
> My current bike is around 30 lbs and has slack seat angle ( < 73 deg ). Would a 32-33 pound with a 76-77 degree seat angle feel easier to climb? Assuming everything else is equal.


This is hard to answer, it's hard to quantify. Generalizations and blanket statements are never a good point of reference, get specific.

What are you riding now? Where do you ride? What are you considering buying instead?

Suspension platform will also impact how a bike feels while climbing. Are you grinding fire roads to get up a mountain or do you have punchy climbs that require short, hard efforts?

These small details matter more than 1-2 lbs in overall bike weight.


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## Bikeventures (Jul 21, 2014)

*OneSpeed* said:


> This is hard to answer, it's hard to quantify. Generalizations and blanket statements are never a good point of reference, get specific.
> 
> What are you riding now? Where do you ride? What are you considering buying instead?
> 
> ...


I ride 2016 Giant Trance. I'm looking at the new crop of short travel 29s like YT Izzo, Ibis Ripley AF, Norco Optic, etc.

My climbs are usually fireroads and double tracks. I'm just curious how much difference the steeper seat tubes make? Would you take that over differential of a few pounds.


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## ocnLogan (Aug 15, 2018)

I don't think the steeper seat tube really does much to increase the efficiency of the bikes pedaling platform. 

Instead, it changes your weight distribution when pedaling up a slope. This keeps taller riders from having their seat be behind the rear axle when the grade gets steep, which can make the bike want to "loop out". The other benefit of that weight shift, is keeping more weight on the front wheel when climbing, which can get a bit light and "floppy", especially with longer, slacker bikes.

So, there could be some benefit for efficiency on steeper climbs, as your weight is farther forward, which means less is on the rear suspension, so it may bob a bit less.

But to answer your question, I wouldn't be bothered by 2-3lbs of difference. Also, are you sure that 2-3lbs is comparing like for like? Because I know bikes like the Optic come with pretty beefy tires. And tires alone can change the bikes weight by 1-3lbs pretty easily.


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## Mudguard (Apr 14, 2009)

How much of the weight increase has come down to the bigger wheels? Go back to a 26" bike and compare the weight to the same modern version with big wheels if they have the same amount of travel? Could it be companies are just speccing decent tyres straight away?


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## BluePitch (Sep 13, 2009)

Bikeventures said:


> I ride 2016 Giant Trance. I'm looking at the new crop of short travel 29s like YT Izzo, Ibis Ripley AF, Norco Optic, etc.
> 
> My climbs are usually fireroads and double tracks. I'm just curious how much difference the steeper seat tubes make? Would you take that over differential of a few pounds.


Steeper STA is beneficial when your climbs are steep and technical. It helps keep your weight over the front wheel. If you have fire roads, double track, or jeep roads STA is not as noticeable as pedal efficiency and weight.
All those bikes you have listed should be good climbers regardless of weight. Weight comes into play IMO as the time you ride increases. The more you spend out on the trail the more you fatigue, the less weight you have to pedal around the less you fatigue. Then there's pedal efficiency, the new crop of short travel 29ers are are pretty efficient, but the Ibis Ripley you mentioned is a damn efficient bike, regardless of weight.


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## Bikeventures (Jul 21, 2014)

The mtb media loves to hype seat angle as the end all right now. That is why I was curious the relation of bike weight and geo.


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## La Nada (Mar 1, 2017)

My last bike had a 73 degree sta. My current bike has a 77 degree sta and is about 2 pounds heavier than the old one. Same wheels and tires on both. The new one climbs much better than the old. I would say the old one was an efficient pedaler too. Little to no bob. Always other variables at play but there's that.


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## {|xDi|} (Dec 2, 2020)

A good seat tube angle is always good, but the weight itself makes a very big difference for me personally. I have a XC style hardtail and ride XC style, so the weight of the bike is important. I shaved about 6 pounds of my hartail & it has made an immense difference. I love it now lol


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## BluePitch (Sep 13, 2009)

Bikeventures said:


> The mtb media loves to hype seat angle as the end all right now. That is why I was curious the relation of bike weight and geo.


STA is definitely important and affects other things besides climbing. If you have a bike with a long reach, you will want a steeper STA to improve your position on the bike. If your STA is too slack and you have a long reach you'll be stretched out on the bike and it will not only be uncomfortable, but hard to apply weight/pressure to the front to help in traction while turning. There is a magic equation that combines STA, HA, reach, chainstay length, BB height, weight, stiffness, tire size, etc, etc that creates a perfect bike....bike companies are still trying to figure it out.


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## jeremy3220 (Jul 5, 2017)

STA should be viewed as part of a package, not an intrinsic factor. You don't need a 78° STA on a XC hardtail with a 80mm stem and 70° HTA. You might want one a 170mm slack enduro bike though.


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## RS VR6 (Mar 29, 2007)

Move your saddle up a couple centimeters. People are making it sound like the saddle is in a fixed position. If your saddle is in a centered position on a 73 degree STA...then move it forward a couple centimeters.

The STA is adjustable up to a point by sliding the saddle back and forth.


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## prj71 (Dec 29, 2014)

RS VR6 said:


> Move your saddle up a couple centimeters. People are making it sound like the saddle is in a fixed position. If your saddle is in a centered position on a 73 degree STA...then move it forward a couple centimeters.
> 
> The STA is adjustable up to a point by sliding the saddle back and forth.


Don't think sliding the seat forward will give you the 75-77 degree STA that are on most modern bikes right now.

In addition to putting your center of gravity further forward, which helps with climbing and making it harder for the front wheel to lift or wander around, the steeper seat tube angle puts the saddle directly over the bottom bracket making the pedaling easier and more efficient.

To a small degree, I also think that the steeper STA on newer bikes might make you more endo prone also.


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## ocnLogan (Aug 15, 2018)

I think the easiest way to visualize what a steep STA does, is to envision a bike with a steep STA riding up a decent grade. Then compare that seated pedaling position of the person riding it to the seated position of someone riding an older mountain bike, or a road bike, which is pedaling on flat ground. The change to a steeper STA, more closely mimics the "normal" pedaling position when you're on a grade. 

Where with a "normal" STA (maybe 73 degrees), you'd be kind of "falling off the back" of the bike when it gets steeper. Again, this should be most noticeable for taller riders, who would otherwise have to be clinging to the bars because their higher, and farther back CoG would be pulling harder on them. So a steeper STA is meant to make you feel less hunched over, which in itself is somewhat tiring.

Which, of course means that if you're NOT riding steep hills, but are instead pedaling along at a flatter grade, you might feel slightly pitched forward, which some people find uncomfortable (which really depends on the stack height of the frame IMO).

Also, steeper STA's make the most sense on longer travel bikes. As when the trail gets steeper, the riders weight shifts farther back, and compresses the suspension more, which makes things worse. Shorter travel bikes have less of this effect, and should have correspondingly less steep STA, which I think is generally reflected in the market today.


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## *OneSpeed* (Oct 18, 2013)

prj71 said:


> To a small degree, I also think that the steeper STA on newer bikes might make you more endo prone also.


Umm, No. With longer, slacker front ends and dropper posts, going OTB is probably less common than ever before.


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## prj71 (Dec 29, 2014)

*OneSpeed* said:


> Umm, No. With longer, slacker front ends and dropper posts, going OTB is probably less common than ever before.


I can go along with that. 80% of the time I forget that I have a dropper post. Still not used to it yet.


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## TrailBlaza (Sep 2, 2008)

The comments here are hilarious. If a steep seat angle makes things so much better why are $8000 XC bikes still rocking 73 degree seat angles? That answer is because you generate more power in that position. A steep angle helps when you have stupid short chainstays and a light and slack front end which will wander if you are set back too much. My heckler has ~73 degree seat angle but also has a coil in the front and a long chainstay which makes climbing good. The three main factors for climbing better are 1) Don't be overweight 2) dont have an overweight bike 3) dont have peddle bob


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## jeremy3220 (Jul 5, 2017)

TrailBlaza said:


> The comments here are hilarious. If a steep seat angle makes things so much better why are $8000 XC bikes still rocking 73 degree seat angles?


There are a few WC winning bikes with 74-74.5° STA's. But as mentioned earlier, STA is used in concert with the rest of the geo to maintain weight balance while seated. An XC bike with a 68° HTA, low stack, longer stem, less travel will be well balanced with a slacker STA. An enduro bike with a slacker HTA, higher stack, shorter stem and longer travel needs a steeper STA will be well balanced with a steeper STA. Remember, when we discuss STA numbers, we're looking at static numbers on flat ground...but the seat tube angle on an enduro bike slackens out to a much greater degree on a steep climb than an XC bike.


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## targnik (Jan 11, 2014)

STA is the latest buzz acronym, to sell more bikes.

My four steeds range from 73° to 76° STA and they all suck at climbing...

...but, that's just personal preference. 

They all rock at DH 

Sent from my HD1900 using Tapatalk


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## kapusta (Jan 17, 2004)

Its not a matter of one aspect compensating for another.

If the bike does not have the geo you want, suspension and weight are basically irrelevant, as you should just skip buying that bike.


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## Zguitar71 (Nov 8, 2020)

There is definitely a relationship between STA and reach. Now that a medium bike has 450mm or more reach, without a steep STA the top tube distance would be too long for someone my size (5’8”) to physically ride the bike seated. I think there is an added benefit when climbing a steep trail of keeping your weight over the rear for traction and over the front enough to keep it planted. That is just one of many things that must come together to make a good climber. The suspension must absorb bumps but bob while pedaling, decent tires for traction, a front end that is controllable and so on. I think the shorter offset forks play a big role in keeping the slack head angle under control and help the rider put their effort into pedaling and less trying to control the bike. If any aspect of the formula sucks then the bikes ability is is held back. If it all comes together then a light or heavy bike can be capable. Take away weight with all other things being the same and the effort needed to move it will be easier.


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## Sanchofula (Dec 30, 2007)

TrailBlaza said:


> The comments here are hilarious. If a steep seat angle makes things so much better why are $8000 XC bikes still rocking 73 degree seat angles? That answer is because you generate more power in that position. A steep angle helps when you have stupid short chainstays and a light and slack front end which will wander if you are set back too much. My heckler has ~73 degree seat angle but also has a coil in the front and a long chainstay which makes climbing good. The three main factors for climbing better are 1) Don't be overweight 2) dont have an overweight bike 3) dont have peddle bob


Not exactly.

The seat tube angle is not what matters, but where your seat is located relative to the bottom bracket, there are some funny numbers out there...

I'm also not convinced that being behind the pedals is better than being on top or in front of the pedals, esp when we're talking about pedaling seated vs pedaling standing.

Mountain bikes with suspension are far removed from road bikes, fitting a bike is not the same as it was twenty years ago.


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