# any 29ers in dh?



## nauc (Sep 9, 2009)

are there any companies that even make 29er dh bikes? 

just curious

thanks


----------



## Rob-Bob (Jun 11, 2004)

I have only seen one in person. It was made by a company called Lenz. ( I think that's how you spell it). KHS had some prototypes last year but I don't know if they ever started producing them..


----------



## nauc (Sep 9, 2009)

interesting

thanks


----------



## Pau11y (Oct 15, 2004)

Intense was testing a chassis based on the 951, weren't they? I have no idea how they got along w/ it tho.

Edit: 2951


----------



## nauc (Sep 9, 2009)

idk, ill look into it, thanks


----------



## ColinL (Feb 9, 2012)

there's no true DH 29er that I know of, but there are some 6"+ bikes which have been used for enduro racing, and there are definitely supergravity and wire-bead 29er tires available.

specialized enduro 29 is one example.

I think you would have a problem with bottom bracket and bar height on a 8+" 29er, but there might be a way to do it. wheelbase also would get pretty long. perhaps the same reason why DH forks haven't gone above 200mm?


----------



## Pau11y (Oct 15, 2004)

ColinL said:


> I think you would have a problem with bottom bracket and bar height on a 8+" 29er, but there might be a way to do it. wheelbase also would get pretty long. perhaps the same reason why DH forks haven't gone above 200mm?


What kind of BB problem...too tall? 
BB drop being more critical than BB height relative to the ground...and can almost be a static value relative to the wheel axle center...I'd imagine a larger wheel diameter would facilitate a better BB height even if it is over 14.5", no?


----------



## ColinL (Feb 9, 2012)

Pau11y said:


> What kind of BB problem...too tall?
> BB drop being more critical than BB height relative to the ground...and can almost be a static value relative to the wheel axle center...I'd imagine a larger wheel diameter would facilitate a better BB height even if it is over 14.5", no?


yep, I'm thinking a 29er with 8"+ rear travel would have a BB higher than a 27.5 or 26" DH bike by necessity, but then again I'm not designing bikes for a living...


----------



## Pau11y (Oct 15, 2004)

ColinL said:


> yep, I'm thinking a 29er with 8"+ rear travel with have a BB higher than a 27.5 or 26" DH bike by necessity, but then again I'm not designing bikes for a living...


It would be pretty tall...and the wheel base...! But again it's the bb drop relative to the axle centers of the wheel off that's tied to stability (and wheel base).


----------



## Rob-Bob (Jun 11, 2004)

ColinL said:


> there's no true DH 29er that I know of, but there are some 6"+ bikes which have been used for enduro racing, and there are definitely supergravity and wire-bead 29er tires available.


The Lenz PBJ is a full on DH. 29er.Check out their website.. I have seen someone riding one in person and it looked like it handled like sh!t..29" wheels on a D.H. frame just doesn't make any sense unless you ride trails with no turns.


----------



## charging_rhinos (Jul 29, 2008)

I just can't take the PBJ seriously. I mean, look at it. It looks like the old Bender Karpiel carcass toss bikes of '99-'01. And from their webpage it appears that they're moving away from the 29er wheels in favor of 27.5. Doesn't really change my mind. *shudder* I respect that they're trying new things. Creating a new style of bike is no easy task. But dang...


----------



## Rob-Bob (Jun 11, 2004)

charging_rhinos said:


> I just can't take the PBJ seriously. I mean, look at it. It looks like the old Bender Karpiel carcass toss bikes of '99-'01. And from their webpage it appears that they're moving away from the 29er wheels in favor of 27.5. Doesn't really change my mind. *shudder* I respect that they're trying new things. Creating a new style of bike is no easy task. But dang...
> 
> View attachment 981983


thanks for posting that picture..Like they say a picture is worth a thousand words and that picture just screams WTF a thousand times.


----------



## mmckechnie (Jul 12, 2010)

Pau11y said:


> Intense was testing a chassis based on the 951, weren't they? I have no idea how they got along w/ it tho.
> 
> Edit: 2951


Here's a video of it.


----------



## nauc (Sep 9, 2009)

charging_rhinos said:


> I just can't take the PBJ seriously. I mean, look at it. It looks like the old Bender Karpiel carcass toss bikes of '99-'01. And from their webpage it appears that they're moving away from the 29er wheels in favor of 27.5. Doesn't really change my mind. *shudder* I respect that they're trying new things. Creating a new style of bike is no easy task. But dang...
> 
> View attachment 981983


that looks like a bike for little kids or something... it looks weird


----------



## rep_1969 (Mar 25, 2004)

I've seen a version of that Lenz "DH bike" here in Winter Park a lot. The thing is a joke, trust me. I'm sure the guys that ride them don't think so, but then again, they are riding 29-inch wheeled "DH bikes".


----------



## mikesee (Aug 25, 2003)

nauc said:


> are there any companies that even make 29er dh bikes?
> 
> just curious
> 
> thanks


I've owned a Lenz PBJ for ~4 years now. Very fast, very fun, very stable. Downsides = if you're shorter than ~5'7" you're gonna drag your ass on the rear tire on super steeps. Otherwise these bikes rip.


----------



## rodgerdodger (Mar 30, 2010)

nauc said:


> are there any companies that even make 29er dh bikes?
> 
> just curious
> 
> thanks


I've been riding a pbj for 3 years and love it. These things rip. A lot of people in this thread are just speculating and haven't actually ridden one.

For comparison (bottom bracket height)
PBJ: BB is 14" 
demo 8: BB is 13.5

wheelbase (cornering)
PBJ: 47.25
demo 8: 48.5


----------



## NWS (Jun 30, 2010)

PBJ | Lenz Sport

I wish they'd publish reach, stack, and seat-tube-length measurements.

The proportions look weird in the pictures, but maybe the fork wouldn't look so freakishly long if the seat wasn't so low. Or maybe the seat isn't low and the fork really is long and the stack really is huge. I can't tell from the pictures or the numbers.

The thing I'm most suspicious about is that with a 29er the rear wheel path is almost required to arc forward. With 26ers the axle typically sits lower than the BB so you get some rearward movement for the first inch or so of travel, but with a 29er you have to raise the axle relative to the BB. The chainstay is basically horizontal in those pictures which means the wheel arcs forward.

You could address that by raising the BB. Basically just scale up a 26er. Not sure if good idea. Not sure if bad idea either, though. Sure your CG would be higher but your WB would also be longer and your wheels would be more likely to roll over things that would pitch a 26er forward. Might be interesting to try that, but I'm not sure I'd buy that.

Or you could get a rearward wheel path by putting the pivot 1.5 inches higher than usual. But then you have a chain growth problem. You could fix the chain growth with an idler pulley like Canfield uses on their Jedi. And if you're going with an idler you might as well put the pivot 3 inches higher than usual and get a very rearward wheel path. (Which appeals to me, because I like my Jedi so much.)

Mostly I wish they'd just publish more geometry numbers so I could make sense of those pictures. It looks so weird.


----------



## mikesee (Aug 25, 2003)

NWS said:


> PBJ | Lenz Sport
> 
> I wish they'd publish reach, stack, and seat-tube-length measurements.
> 
> Mostly I wish they'd just publish more geometry numbers so I could make sense of those pictures. It looks so weird.


That purple bike pictured in your link is a small frame, with 650b wheels. Which is IMO why it looks so weird.

Here's a pic of mine:

https://picasaweb.google.com/mike.c...key=Gv1sRgCJvBk4qpwoTNrwE#6036450725258160290

29" wheels, 2.5" Minion DHF's, medium frame, 180mm travel Dorado, 32t chainring.

No idea on reach or stack.


----------



## Mudguard (Apr 14, 2009)

mikesee said:


> Here's a pic of mine:
> 
> https://picasaweb.google.com/mike.c...key=Gv1sRgCJvBk4qpwoTNrwE#6036450725258160290


I've never seen a headset mounted like that? Well a Chris King with the logos upside down?
I must say the bike looks very unusual. I'm guessing because the downtube has to clear a bigger wheel so it cramps it up somewhat.


----------



## NWS (Jun 30, 2010)

mikesee said:


> That purple bike pictured in your link is a small frame, with 650b wheels. Which is IMO why it looks so weird.
> 
> Here's a pic of mine:
> 
> ...


You're right, the small frame was a big factor. I'm used to seeing the seat somewhere between the height of the head tube or maybe level with the handlebars. So the seat being lower than the bottom of the head tube just looked strange. Yours looks pretty reasonable.

Small frame + 29er wheels = weird looks no matter what kind of bike, so I should have guessed.


----------



## mojoronnie (Feb 26, 2012)

29ers will never work for dh.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> 29ers will never work for dh.


Bzzzzt--wrong answer. Been working for years. Maybe they're not for you, where you live, but I'm guessing you've never seen much less ridden one to really know for sure.


----------



## smilinsteve (Jul 21, 2009)

Rob-Bob said:


> thanks for posting that picture..Like they say a picture is worth a thousand words and that picture just screams WTF a thousand times.


The only thing wrong with how that bike looks is that it goes against what you are accustomed to. Open your mind, man


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> Bzzzzt--wrong answer. Been working for years. Maybe they're not for you, where you live, but I'm guessing you've never seen much less ridden one to really know for sure.


Obviously our definitions of DH differs. If you like to rip berms, huck jumps, whip it, manual, pump it and just get your shred on then I'm not sure a 29er is the bike of choice. Now if you're referring to any trail that goes dh as dh riding then a 29er will work as any bike would.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> Obviously our definitions of DH differs. If you like to rip berms, huck jumps, whip it, manual, pump it and just get your shred on then I'm not sure a 29er is the bike of choice.


Our definition is emphatically the same. Sounds like you haven't ridden one. Don't knock it til you've tried it.

P.S. They erase 26" braking bumps too...


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> Our definition is emphatically the same. Sounds like you haven't ridden one. Don't knock it til you've tried it.
> 
> P.S. They erase 26" braking bumps too...


I have ridden one. Hated it. I might consider a 29er for long xc rides but that's about it for me. Long chain stays take the fun out of the ride for me.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> I have ridden one. Hated it. I might consider a 29er for long xc rides but that's about it for me. Long chain stays take the fun out of the ride for me.


You rode a 29" trailbike, or DH bike? Made by whom?

Agreed that long stays (among other things) can make a bike less than playful.

CS length = 437mm on the PBJ. That's right in there (few mm's shorter than some, few mm's longer than others) with most 26" DH bikes on the market.


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> You rode a 29" trailbike, or DH bike? Made by whom?
> 
> Agreed that long stays (among other things) can make a bike less than playful.
> 
> CS length = 437mm on the PBJ. That's right in there (few mm's shorter than some, few mm's longer than others) with most 26" DH bikes on the market.


I rode an evo 29er. I haven't ridden a 29er DH bike. But I couldn't imagine riding a niner in whistler. No way I'd ride that bike on A Line/Dirt Merchant. I just don't feel the playfulness in bigger wheels which is no fun for my style of riding.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> I rode an evo 29er. I haven't ridden a 29er DH bike. But I couldn't imagine riding a niner in whistler. No way I'd ride that bike on A Line/Dirt Merchant. I just don't feel the playfulness in bigger wheels which is no fun for my style of riding.


EVO is a decent trailbike, but nowhere, nowhere near a Whistler-level DH bike. Knife at a gunfight.

I *have* ridden my PBJ at Whistler--3 different trips. Filthy Salesman and A-Line are (big surprise) 2 of my favorite trails on this planet. This bike _rips_ there.

Only problem with the PBJ is how fast I overrun my buddies on 26" bikes. Passing 'em in the air, laid out flat and making moto noises, on that 3-pack of tables near the top of A-Line is one of my all-time-favorite bike-specific memories.

Key words in your post = _"I couldn't imagine"_. Clearly you can't. And that's OK--big wheels ain't for everyone. I'm *psyched* that most people are still on 26" wheels at bike parks, because (as mentioned earlier) of how my 29" wheels just erase those 26" brake bumps.

Peace,

MC


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> EVO is a decent trailbike, but nowhere, nowhere near a Whistler-level DH bike. Knife at a gunfight.
> 
> I *have* ridden my PBJ at Whistler--3 different trips. Filthy Salesman and A-Line are (big surprise) 2 of my favorite trails on this planet. This bike _rips_ there.
> 
> ...


I love the 3 pack on top.... I'm sure it's fast, But I wouldn't say its faster/better than a 26" bike on A Line. If the pbj was superior to 26 or even 650b then you would see it in Air Dh. have you ever seen Lopes on A Line on a 26" bike? I rode behind him last year at crankworx... ridiculous speed. Maybe I'll demo one at crankworx this summer, If I see one, just to see what its all about......


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> I love the 3 pack on top.... I'm sure it's fast, But I wouldn't say its faster/better than a 26" bike on A Line. If the pbj was superior to 26 or even 650b then you would see it in Air Dh. have you ever seen Lopes on A Line on a 26" bike? I rode behind him last year at crankworx... ridiculous speed. Maybe I'll demo one at crankworx this summer, If I see one, just to see what its all about......


Don't confuse the rider with the bike.


----------



## Radioinactive (Aug 2, 2011)

29" downhill bikes are going to be a reality, and I will welcome it with open arms!!!!!!


----------



## mojoronnie (Feb 26, 2012)

Radioinactive said:


> 29" downhill bikes are going to be a reality, and I will welcome it with open arms!!!!!!


I doubt that. Their may be some manufacturers selling them but they will never be raced professionally on the UCI Circuit. If the top pros aren't racing them then the manufacturers won't be making them. UCI courses demand quick agile bikes with room to move around. Try hanging off the back of a niner at speed in the steeps.. Not gonna happen


----------



## NWS (Jun 30, 2010)

Yeah, DH has always been 26" and will always be 26". Anything bigger just won't work.


----------



## Rob-Bob (Jun 11, 2004)

NWS said:


> Yeah, DH has always been 26" and will always be 26". Anything bigger just won't work.


650 b seems to work just fine.. Just look at what all of the pro's are riding.


----------



## LarryFahn (Jul 19, 2005)

In 2007 I took a group of buddy's DHing for their first time. All they did was complain about how small the wheels were and how weird 26" bikes felt. By the end of the day everyone was having a blast. One of my buddies bet me $20 that within 3 years everybody there (downhillers) would be on 29ers...

8 years later and $20 richer! 

There's one company that makes one (listed above). Intense pulled a great publicity stunt at I-bike with their 29". But if it were going to happen, it would have. With companies like S, T, and Niner (of all companies) pretty much depending on the 29" wheel market. Yet none of them even attempted it. Why? Even the president of Intense said the bike wasn't practical. 

Last year though 650 caught on and S and T even changed over. The industry now has something new to push. This will be the way for the next 6 years at least. Let lents make their bike. They're a small business and this is the only bike I've seen by them. There's one I saw last year at Creek. 

Anyway, this topic is pretty much dead... For another 6 months. That's when someone will come on here and ask "Why aren't there any 29er DH bikes" or "I'm 6-4 and need a 29" DH bike". 

Ttyl, Fahn


----------



## ColinL (Feb 9, 2012)

Rob-Bob said:


> 650 b seems to work just fine.. Just look at what all of the pro's are riding.


Because it's all of 4.5% bigger than 26". :lol:


----------



## Rob-Bob (Jun 11, 2004)

ColinL said:


> Because it's all of 4.5% bigger than 26". :lol:


Still bigger...And 650 b does make a noticeable difference..Some good some bad..


----------



## mojoronnie (Feb 26, 2012)

Rob-Bob said:


> 650 b seems to work just fine.. Just look at what all of the pro's are riding.


The pros ride what the manufacturer tells them to ride. If they had a choice, it wouldn't be 650b. Hang out in Whistler and check out what the local shredders are riding. 26 for a reason.


----------



## Rob-Bob (Jun 11, 2004)

mojoronnie said:


> The pros ride what the manufacturer tells them to ride. If they had a choice, it wouldn't be 650b. Hang out in Whistler and check out what the local shredders are riding. 26 for a reason.


Just wait and see what people are riding at whistler in another season or two..Once more people try the 650 B format and realise it's not that different from the 26" bikes more people will start buying them.


----------



## TheDwayyo (Dec 2, 2014)

mojoronnie said:


> The pros ride what the manufacturer tells them to ride. If they had a choice, it wouldn't be 650b. Hang out in Whistler and check out what the local shredders are riding. 26 for a reason.


That is such nonsense. The pros ride what they determine to be fastest. If what you say were true they'd all be on current production bikes, because that would boost sales. That's not the case though; they mostly ride pre-production prototypes or one-off custom versions of production bikes... Because their goal is to win, not sell bikes. (Though of course winning does sell bikes, but that's not the racer's direct concern.)



Rob-Bob said:


> Just wait and see what people are riding at whistler in another season or two..Once more people try the 650 B format and realise it's not that different from the 26" bikes more people will start buying them.


I agree, but that won't be proof of anything except a shift in what wheel sizes are most commonly available on the market.


----------



## mojoronnie (Feb 26, 2012)

TheDwayyo said:


> That is such nonsense. The pros ride what they determine to be fastest. If what you say were true they'd all be on current production bikes, because that would boost sales. That's not the case though; they mostly ride pre-production prototypes or one-off custom versions of production bikes... Because their goal is to win, not sell bikes. (Though of course winning does sell bikes, but that's not the racer's direct concern.)
> 
> I agree, but that won't be proof of anything except a shift in what wheel sizes are most commonly available on the market.


That's not true. The pros ride what their sponsors tell them to ride. If The manufacturer/sponsor sells 650b Dh bikes do you think they would like it, or allow for their rider to ride a 26" bike if the rider thought he was faster on it? Hell No. Thats not going to help sell their 2015 650b. Manufacturers are all about selling bikes first and foremost. The have race teams in order to promote and develop their product, and yes, winning is important because it gives them exposure, and sells more bikes at the end of the day and thats all that matters. If manufacturers are not selling bikes, then theres no money to pay racers to race. Motocross is the same way. Do you think KTM pays Dungey the big bucks to win races just for the sake of winning races? No way. They know by him winning they're going to sell lots of new KTMs. As for one offs, You're right. They are prototypes for future bikes. You will never be able to buy Dungeys actual race bike, but you will be able to buy a ktm with plenty of new features from his winning bike the following year. Riding up the chair at whistler crankworx I chatted with lots of the pros and they all said its a shame what the manufacturers have done to the 26" bike. Its still the fastest and most fun dh wheel size, but they can't ride it because they're getting paid to to ride what the manufactures wants to sell.


----------



## smilinsteve (Jul 21, 2009)

Poor pro riders riding slower bikes because the evil sponsors force them to! 

Now that is complete crap!


----------



## mojoronnie (Feb 26, 2012)

smilinsteve said:


> Poor pro riders riding slower bikes because the evil sponsors force them to!
> 
> Now that is complete crap!


lol obviously you've bought into the 650b is faster bull sh*t bahahahahahahahahaha


----------



## smilinsteve (Jul 21, 2009)

mojoronnie said:


> lol obviously you've bought into the 650b is faster bull sh*t bahahahahahahahahaha


No sir. I think most downhillers ride 27.5 because they liked it or they are neutral about it. I think if a pro hated 27.5 he simply wouldn't use that size. I have read about riders sticking with 26, or switching back and forth without repercussions from the sponsor. I don't know how many pros still ride 26, but I have no doubt that they can. 
If there was a whole bunch of pros who hated 27.5 as you suggest I think that would drive the market, but that isn't the case.


----------



## mojoronnie (Feb 26, 2012)

smilinsteve said:


> No sir. I think most downhillers ride 27.5 because they liked it or they are neutral about it. I think if a pro hated 27.5 he simply wouldn't use that size. I have read about riders sticking with 26, or switching back and forth without repercussions from the sponsor. I don't know how many pros still ride 26, but I have no doubt that they can.
> If there was a whole bunch of pros who hated 27.5 as you suggest I think that would drive the market, but that isn't the case.[/QU
> 
> The manufacturer pays the rider to race their product. The rider doesn't have a choice.. the manufacturers have eliminated 26, not the riders.


----------



## NWS (Jun 30, 2010)

Pro tip: don't believe anything written in comic sans.


----------



## LarryFahn (Jul 19, 2005)

mojoronnie said:


> The manufacturer pays the rider to race their product. The rider doesn't have a choice.. the manufacturers have eliminated 26, not the riders.


"I think we want you to slow down your speeds. Here's a 27.5 bike. " says the ceo/team manager for the company.


----------



## mojoronnie (Feb 26, 2012)

LarryFahn said:


> "I think we want you to slow down your speeds. Here's a 27.5 bike. " says the ceo/team manager for the company.


obviously you have no clue why manufacturers supply bikes to teams. Think about it and maybe you will hear a ding ding along the way. But be careful not to hurt yourself while thinking


----------



## sandwich (Sep 24, 2005)

manufactures supply bikes to pros so they can sell those same bikes to customers. Nobody wants a pro racing and winning on a bike that normal people can't buy; that defeats the purpose of sponsorship.

As for viable 29er DH bikes, you could do the Lenz PBJ or grab an enduro 29er and hang a dorado set at 180mm on it. I've thought about doing that, but then I got a great deal on a real DH bike and the pike is a very very capable fork. Plus specialized doesn't recommend longer travel forks on the enduros. Otherwise not many people make longer travel 29ers, as the 650b "revolution" knocked 29ers out of favor.

As far as why the intense never took off, it was built before the minion DHF even existed in 29" format. I can only imagine how bad any bike would perform with inferior tires, when the option of real tires exists. I think we may see another 29er DH bike in the future, but most people have bought 650b hook line and sinker, and it would be tough to upset that marketing strategy.


----------



## ColinL (Feb 9, 2012)

sandwich said:


> I think we may see another 29er DH bike in the future, but most people have bought 650b hook line and sinker, and it would be tough to upset that marketing strategy.


there is only so much you can do with the suspension because of the length of the fork and corresponding bar height. (Check the bar, footpeg and seat height of a 450 motocross bike with it's 12" fork and compare that to a 8" DH MTB fork.)

working around those limits is the main reason why we still have 203mm forks on both 26 & 27.5 DH bikes, and why most of those bikes have 8" rear travel or two pivot locations for 8" and 10".

when you account for the larger diameter of a 29er wheel, something has to give.


----------



## Varaxis (Mar 16, 2010)

Don't forget that the UCI rules filter out a lot of "radical" designs.


----------



## mikesee (Aug 25, 2003)

Only two park days in thus far this year, but starting to ramp that up as a 2-week bender in Whistler approaches.
​


----------



## mmckechnie (Jul 12, 2010)

So Trek has been playing around with a prototype Session 29. I bet this would destroy the rougher world cup tracks.

Mountain Bike Action Magazine | Spy Shot ? Trek?s New Prototype 29er Session DH Bike


----------



## Radioinactive (Aug 2, 2011)

LarryFahn said:


> In 2007 I took a group of buddy's DHing for their first time. All they did was complain about how small the wheels were and how weird 26" bikes felt. By the end of the day everyone was having a blast. One of my buddies bet me $20 that within 3 years everybody there (downhillers) would be on 29ers...
> 
> 8 years later and $20 richer!
> 
> ...


haha theyve been riding them for some time at "T". Mountain Bike Action Magazine | Spy Shot - Trek's New Prototype 29er Session DH Bike. i said it b4 ill say it again, 29er DH bikes are the future!


----------



## Lelandjt (Feb 22, 2008)

Varaxis said:


> Don't forget that the UCI rules filter out a lot of "radical" designs.


In what way? I've never seen a UCI MTB rule that limits equipement.


----------



## Lelandjt (Feb 22, 2008)

mmckechnie said:


> So Trek has been playing around with a prototype Session 29. I bet this would destroy the rougher world cup tracks.
> 
> Mountain Bike Action Magazine | Spy Shot ? Trek?s New Prototype 29er Session DH Bike
> 
> View attachment 1004475


So a 29" wheel and DH tire fit in a 27.5" Fox 40?


----------



## mmckechnie (Jul 12, 2010)

Lelandjt said:


> So a 29" wheel and DH tire fit in a 27.5" Fox 40?


I'm guessing Fox whipped up a prototype 29 40.


----------



## Lelandjt (Feb 22, 2008)

mmckechnie said:


> I'm guessing Fox whipped up a prototype 29 40.


Those are cast magnesium lowers. If Fox made that fork than it's nearly production ready. Nobody makes molds for a prototype.


----------



## Pau11y (Oct 15, 2004)

Lelandjt said:


> So a 29" wheel and DH tire fit in a 27.5" Fox 40?


Looking at the clearance, albeit a bit far away, it looks like it fits. Maybe Trek also shaved a bit of the underside of some of the arch? There was an old thread where folks did that to the 26er Fox 36 arch to get a bit more than ~3/16" clearance for a fat 27.5" tire...


----------



## mojoronnie (Feb 26, 2012)

29ers have no place in DH. The physics alone tell us that. This is ridiculous.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> 29ers have no place in DH. The physics alone tell us that. This is ridiculous.


While you were failing physics this week, I was out riding DH with friends, some on 27.5" and others on 29" wheels.

Open your mind--it's just a bike.


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> While you were failing physics this week, I was out riding DH with friends, some on 27.5" and others on 29" wheels.
> 
> Open your mind--it's just a bike.


I have opened my mind, that's what public forums are all about. Just because you don't agree with my opinion doesn't mean it's not valid. Did you not learn about rotating mass or did you ditch school that year? Ride what you like, but the physics don't lie.


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> I have opened my mind, that's what public forums are all about. Just because you don't agree with my opinion doesn't mean it's not valid. Did you not learn about rotating mass or did you ditch school that year? Ride what you like, but the physics don't lie.


You're right--we don't have to have matching opinions.

Read back through your posts, just in this thread. You have, in essence, flatly stated that it can't work, won't work, defies physics, is being forced on racers, etc... So your opinion is clear.

What you haven't provided are any sort of facts or evidence to back up this opinion. Maybe you could enlighten us on why what's already been done for years, and really well by many, is somehow actually impossible.


----------



## Le Duke (Mar 23, 2009)

People said the same thing about 29ers in WC XC 7+ years ago. "They'll never take off. They spin up too slow." And now, the vast majority of pro XC racers are on them. And 26" wheel bikes are essentially extinct in that arena.


----------



## sandwich (Sep 24, 2005)

I would like to know what physics are incompatible with downhill racing.

Carries more momentum
More Stable
Slows steering
Better rollover
Theoretically can be run with less travel
Flexible wheels can smooth out rough corners
Narrower contact patch could make for more position sensitive tires (pros lean their bikes, ams turn)

Outside of the initial sprint, what's the downer? Nobody has really ever done it because there were never good tires...now there are.


----------



## cerebroside (Jun 25, 2011)

sandwich said:


> I would like to know what physics are incompatible with downhill racing.
> 
> Carries more momentum
> More Stable
> ...


There is some nebulous strength disadvantage, though I have no idea if that's a big deal since broken rims don't seem to end many race runs. Would love to see someone quantify it.


----------



## mikesee (Aug 25, 2003)

Le Duke said:


> People said the same thing about 29ers in WC XC 7+ years ago. "They'll never take off. They spin up too slow." And now, the vast majority of pro XC racers are on them. And 26" wheel bikes are essentially extinct in that arena.


Well put. Eventually people will come to realize that the main impediment to 29" wheels in DH applications is not in any way technical or "physics" related at all--it's actually just closed minds.

You can perceive problems with anything you don't like, or don't want to like. But once you try it, and spend time on it, you realize that it doesn't merely work, it also has some serious advantages.


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> You're right--we don't have to have matching opinions.
> 
> Read back through your posts, just in this thread. You have, in essence, flatly stated that it can't work, won't work, defies physics, is being forced on racers, etc... So your opinion is clear.
> 
> What you haven't provided are any sort of facts or evidence to back up this opinion. Maybe you could enlighten us on why what's already been done for years, and really well by many, is somehow actually impossible.


I didn't say it can't work, any bike can be ridden down a mountain. I just don't think it's the right tool for the job.

Nothing affects performance like rotating mass. That being said, Why would you add weight to a wheel set when you don't have to?

1. Bigger wheels flex more, last thing you want when hauling ass is a flexible wheel set.

2. Bigger wheels don't stop nearly as well as a 26er. I use to run mavic 823's then switched to Deemax Ultimate. I shaved 1 lb of rolling mass, I could come into corners so much hotter, braking at the last minute. It's amazing how much performance you gain from a lighter, nimble wheels set. 29ers are the exact opposite. Heavier, more rotating mass which means you have to brake earlier, not nearly as nimble which slows your steering response.

3. 26ers run shorter rear stays, which in turn gives you a bike that accelerates faster, is way more snappy in the corners and your chances of getting bucked and going over the bars are far less.

4. 29ers dont handle nearly as well. Run a world cup course at pro speed. They split lots of trees. The last thing I need is a bike that takes longer to correct when I'm moving out. Smaller wheels just simply handle better.

5. Nothing jumps like a sixer!

6. Smaller wheels run lower bottom brackets. Dh is all about corner speed, nothing corners faster than a bike built with a low BB.

I could go on and on. If you like riding a 29" Dh bike then do so. But this is DH, not XC.
There are no benefits to riding those big, awkward wheels for Dh racing on a true DH course, not some weak peddle course with a DH label on it.


----------



## mojoronnie (Feb 26, 2012)

sandwich said:


> I would like to know what physics are incompatible with downhill racing.
> 
> Carries more momentum
> More Stable
> ...


OMG... I've heard it all. "Flexible wheels smooth out corners". "Slower Steering"??? lol That's the last thing you want. And btw, If you're not leaning your bike, you're not riding it!


----------



## mikesee (Aug 25, 2003)

mojoronnie said:


> I just don't think...


Thanks for chiming back in--you have effectively made my point for me. Many of your arguments are subjective, not based in science or 'physics', and the rest can be easily refuted: there are short-CS 29" bikes, and 29" rims and tires that are the same or lighter than equivalent 26", etc...

You don't have to like them or ride them, just stop claiming things ("There are no benefits", "Don't handle as well") that are untrue or unprovable.

Oh--and educate yourself before you foam off any further (hint: BB height is not a function of wheel size) because ignorance kills...


----------



## mojoronnie (Feb 26, 2012)

mikesee said:


> Thanks for chiming back in--you have effectively made my point for me. Many of your arguments are subjective, not based in science or 'physics', and the rest can be easily refuted: there are short-CS 29" bikes, and 29" rims and tires that are the same or lighter than equivalent 26", etc...
> 
> You don't have to like them or ride them, just stop claiming things ("There are no benefits", "Don't handle as well") that are untrue or unprovable.
> 
> Oh--and educate yourself before you foam off any further (hint: BB height is not a function of wheel size) because ignorance kills...


Just go ride your wagon wheels. I'd love to ride with you sometime. Not sure what you're excuse will be when you get dropped by those tiny obsolete 26" wheels. Uh oh. That sure would suck! Hehe


----------



## NWS (Jun 30, 2010)

Exactly correct. Physics also tells us that 24" wheels would be even better. That'd be like taking all of the advantages of 26" wheels and making them even more advantageous. Because physics.


----------



## Mudguard (Apr 14, 2009)

A factory backed rider might get away with racing a DH bike with 29" but consumers would destroy the wheels on no time. 
Unless the widen the flanges somehow and then it might get close to a 26. As for the different size wheels, wheel there's obviously a sweet spot. A 30" might roll over everything but it's the bugger that's perched on top of it that the bike still has to fit. Same going the other way 20" wheels are incredibly strong, yet will get caught up in a lot of junk. So there is a sweet spot. 
I was reading an article discussing how much stronger a non disc wheel was compared to the wheels wet have now.


----------



## Radioinactive (Aug 2, 2011)

mojoronnie said:


> Just go ride your wagon wheels. I'd love to ride with you sometime. Not sure what you're excuse will be when you get dropped by those tiny obsolete 26" wheels. Uh oh. That sure would suck! Hehe


quit making yourself out to be a jerk. I dont know if you're just ignorant or a troll but you're TRYING to argue with mountain bike legend Mike Curiak. the dude will surely drop you so you might wanna chill out! Like what the hell hahaa????


----------



## mojoronnie (Feb 26, 2012)

Radioinactive said:


> quit making yourself out to be a jerk. I dont know if you're just ignorant or a troll but you're TRYING to argue with mountain bike legend Mike Curiak. the dude will surely drop you so you might wanna chill out! Like what the hell hahaa????


I'm pretty sure I'm not getting dropped I'll leave it at that though. 29ers still suck and don't belong in dh.


----------



## NWS (Jun 30, 2010)

> Pick a wheel size a be a dick about it.


It's not just a good idea, it's the law.


----------



## mikesee (Aug 25, 2003)

Vital MTB Bike of the day for 8/11/2015.


----------



## mikesee (Aug 25, 2003)

Mudguard25 said:


> A factory backed rider might get away with racing a DH bike with 29" but consumers would destroy the wheels on no time.


People have been claiming that for a decade+, but it just isn't happening. Sure, wheels (of any size) can be killed, and the lighter they are the more likely this is to happen. But they just aren't being wadded up and destroyed the way people have suggested.

Unless you mean dents and flatspots--which are a function of the rim, tire, and tire pressure, but have little to nothing to do with diameter.


----------



## sandwich (Sep 24, 2005)

is there a dedicated DH casing 29er tire? I thought the DHF was like 1.5ply. Very hard to compare apples to apples when most people don't make similar equipment.

Either way I'd be all over a 29er DH bike if I didn't have a very nice 26" DH bike.


----------



## mikesee (Aug 25, 2003)

sandwich said:


> is there a dedicated DH casing 29er tire?


Minion DHF 29 x 2.5 is available in a single ply tubeless ready casing, and a dual ply DH tubeless ready casing.


----------



## Jayem (Jul 16, 2005)

sandwich said:


> is there a dedicated DH casing 29er tire? I thought the DHF was like 1.5ply. Very hard to compare apples to apples when most people don't make similar equipment.
> 
> Either way I'd be all over a 29er DH bike if I didn't have a very nice 26" DH bike.


Minion DHF/DHR 2.5s are plenty tough for DHing. Plenty of DHers don't use the old crazy stiff/strong Intense DH tires from 5-10 years ago, I'd say those are a rarity anymore. The Maxxis casings are the same as what you'd get with the 26" version.

The DHF rocks just as much on a 29er setup as it does 26.

These minions aren't like the old circa 2005 large-volume 26er tires that started showing up with paper-thin casings, I ripped a few of those and realized that a bigger tire DOES have to weigh more. I kind of liken that old phenomenon to current issues with people trying to run 17psi and shattering carbon rims. 600g 2.3" tires just aren't going to work in nasty terrain.

There is NO comparison to the butcher/purgatory combo my E29 came with, those tires are skinny for 2.3 and the sidewalls are thin. I would not recommend serious DH on them. Those are more "all day/big ride" tires.


----------

