[ByStickel]

I know I'm going to be eaten alive, but...

Provided wider hubs and decent rims and tires are produced, do you think 29er will establish itself as a viable platform for DH racing? Could it dominate, some day?

Why? or Why not?

Sign of the Apocalypse, or would people just adopt whatever worked best?

 

[jonKranked]

I rode them when they first came out for xc. Definitely more than just a novelty, and a lot of fun. Wasn't enough to make me run out and buy one though. I've ridden a few here and there since, and the idea has been lingering in the back of my mind for some time (I'm always looking for a new toy ) The technology has gotten better since its introduction, as well as the options. I know a few people have already toyed around with 29" dh bikes (bcd if I'm not mistaken made a few carbon ones). But I still think it might be a few years off for DH. Some questions remain for me... mainly if it will be possible to build a 29" DH wheel strong and light enough to handle downhill riding? (how ridiculous will the cost be, even for this sport?) Would the UCI ban them unless everyone chose to ride them? Would people still e-speculate about them?

I think they're still a few years out for widespread DH use; but then again a bunch of dh29'ers might be unveiled at Interbike.

 

[dropmachine]

probably catch on just as well as 24" DH'ers did.

 

[1453]

probably catch on just as well as 24" DH'ers did.

we need 22 inch DH bikes, it's obvious.

 

[MMike]

ask bcd...

 

[Pslide]

I got lambasted for suggesting this on littermag's chat once...

I reckon 29" will have too much of a compromise in terms of weight, strength, and packaging within the frame with proper geometry.

I think 650B size is much more likely. A better compromise of grip, rolling, weight, and strength. I think is a very viable idea. Just needs a suitable tire for someone to try it. It would take a pretty progressive tire company to invest in the molds, and I don't see it happening soon.

 

[ire]

I'm not going to say it isn't viable, or a good option, but I don't think it will catch on. My suspicion is that the gains would be small compared to the trade offs (wheel strength, tighter wheel clearance, etc).

 

[stumpjump]

If it ever would, rim strength would be perhaps one of the largest issues with the builds. 24in wheels had their time (i.e when they were on the specialized bighit back in its DH days) but I don't really forsee that happening for a long time.

 

[Banshee Rider]

I don't see it taking off any time soon. You're going to need a shift from the entire industry to make it worthwhile; frames, forks, wheels, and especially tires. It's taken forever for the 29 xc market to catch up in regards to trial-and-error geometry and component options, I can't imagine how long it'll take for them to convert a bunch downhillers who are impossible to please.

 

[Sandwich]

DH bikes are a little too close to being perfected to swap to 29ers...but perhaps a few years off. Manufacturers have a pretty good grip on geometry, BB height, CS length, suspension design....in the next 2 years I expect most bike to be pretty darn similar in geometry....so perhaps then you'll see big wheels come into play.

 

[boogenman]

The larger 29 wheels are a lot harder to get off the ground(jump, bunny hop) I do not think it will something that will work out to well for DH.

I am sure we will see some bikes with 29'ers to see if it will work then we will see those bikes fade away like 24's.

 

[Sandwich]

I rode my 24's last weekend...sigh...i'm so irrelevant. If only I painted myself monster green and let my unibrow grow out.

 

[OGRipper]

It's inevitable that people will continue to toy with the idea, but personally I am not too interested. One of the challenges is figuring out how to get long travel with a 29" wheel without it slamming into the frame or seat. (Remember how some folks went with 24" wheels for a while? That was partly because they were having a hard enough time getting long travel with 26" wheels.) So that's a limiting factor. Some people are sold on the added traction and ability to roll over bumps, so maybe we'll see some "69'er" set-ups with a 29" front and 26" rear - but assuming you've got similar front travel as current designs, you'll have a super tall front end. I think the bigger wheels have some potential for larger people, but for average and smaller folks, I find too much front wheel overlap and other compromises.

 

[jonKranked]

It's inevitable that people will continue to toy with the idea, but personally I am not too interested. One of the challenges is figuring out how to get long travel with a 29" wheel without it slamming into the frame or seat. (Remember how some folks went with 24" wheels for a while? That was partly because they were having a hard enough time getting long travel with 26" wheels.) So that's a limiting factor. Some people are sold on the added traction and ability to roll over bumps, so maybe we'll see some "69'er" set-ups with a 29" front and 26" rear - but assuming you've got similar front travel as current designs, you'll have a super tall front end. I think the bigger wheels have some potential for larger people, but for average and smaller folks, I find too much front wheel overlap and other compromises.

If you think about it, it only really adds 1.5" to the radius of the wheel, so I don't think clearance is going to as much of an issue as anticipated. I think my bigger concern is how the necessary geometry tweaks to a frame (longer chainstays) would affect handling, especially cornering.

I definitely agree, we're more likely to see a 69'er than a true 29'er, because this would help raise the front end a touch for descending, and help keep the bike slack. But then again some people might have to resort to using flat handlebars.

 

[LukeD]

If you think about it, it only really adds 1.5" to the radius of the wheel, so I don't think clearance is going to as much of an issue as anticipated. I think my bigger concern is how the necessary geometry tweaks to a frame (longer chainstays) would affect handling, especially cornering.

I definitely agree, we're more likely to see a 69'er than a true 29'er, because this would help raise the front end a touch for descending, and help keep the bike slack. But then again some people might have to resort to using flat handlebars.

if people are trying to get the lowest handlebar height now with low stack headsets, flat or low rise bars and even going as far as grinding out the bottom of boxxer crowns... i can't see the need of a 29er up front if it's going to raise the bar height.

 

[Sandwich]

then again some people might have to resort to using flat handlebars.

some people already do...

One of the things BCD noted was that less travel was actually required when using 29 inch wheels. You've got more traction, less rolling resistance, and theoretically more spoke deflection adding up to a reasonable amount of innate travel.

I personally don't think that they'll catch on, as the acceleration with proper DH tires would be pretty poor, plus things like turning, pinch flatting, etc.

When i slapped my 24's back on, I immediately noticed my bike get nimbler. I can't imagine going to a 29" front wheel on some of these east coast trails. The WFO courses would definitely make sense, however.

 

[pinkshirtphotos]

i dont really care for a dh 29er, i would like to see some dh influenced 29er tyres.... say 2.5 + with aggressive tread.

 

[OGRipper]

If you think about it, it only really adds 1.5" to the radius of the wheel...

Well, an extra 1.5" is pretty huge. Some frame designers would pretty much kill for that much extra room. And I agree with you about geometry, but it's sort of the same argument.

 

[nmr8]

If you think about it, it only really adds 1.5" to the radius of the wheel, so I don't think clearance is going to as much of an issue as anticipated. I think my bigger concern is how the necessary geometry tweaks to a frame (longer chainstays) would affect handling, especially cornering.

I definitely agree, we're more likely to see a 69'er than a true 29'er, because this would help raise the front end a touch for descending, and help keep the bike slack. But then again some people might have to resort to using flat handlebars.

i think that's how it'll happen first, 69er that is. i think the main problem is wheel strength, which i believe is going to require a wider front hub shell. if you make a custom front hub, a custom axle, and custom crowns you can overcome that while still using a stock fork. i think that's relatively doable. iirc bcds wheels were tacoing, not flat spotting, so existing rims should be strong enough, if they're better supported by greater spoke dish.

 

[jonKranked]

One of the things BCD noted was that less travel was actually required when using 29 inch wheels. You've got more traction, less rolling resistance, and theoretically more spoke deflection adding up to a reasonable amount of innate travel.

This is a very good point. I noticed that when I first rode a 29" hardtail, it was much more forgiving than a 26" hardtail, to the point if felt almost like a softtail...

O'Gripper - I agree, an inch and a half is quite a bit to have to add to your chainstays when you think about the overall numbers. But certain suspension designs - like high placed single pivots (with very rearward axle paths) - this wouldn't have as much of an overall impact as others (I think).

I think the big question is... given the amount of geometry modification necessary to accommodate the larger wheel - and its subsequent impact to handling - are riders going to be willing to deal with this to gain the benefits of a larger wheelset?

I think the best way to determine this is to build one and find out.

 

[OGRipper]

if you make a custom front hub, a custom axle, and custom crowns you can overcome that while still using a stock fork. i think that's relatively doable.

Not to be a pessimist but if everything else is wider I think you'd have a problem with the caliper location on a stock fork.

And JK, most high single pivots eventually swing back toward the front. So for example clearance is an issue on a bullit. Maybe something with a real rearward path like a Canfield, but then you need to deal with all the chain growth.

 

[bikenweed]

A large part of downhill is in acceleration and de-acceleration, two areas in which larger wheels perform poorly.

A 69er setup (29 up front) might be nice on fast, wide open courses, but I really doubt it'll be a significant advantage when compared to the loss in acceleration. Minaar tested a 69er setup for Honda, but they stuck with the 26er set up. If it was going to be a significant advantage, they probably would have carried through with the idea.

 

[trailhacker]

Not to be a pessimist but if everything else is wider I think you'd have a problem with the caliper location on a stock fork.

When he said "custom crowns" I took it to mean wider so you could use the same caliper. This could work with an inverted fork, but a standard fork you would have to cut your arch.
I thought he was talking about an inverted fork?

I thought BCD was using a White Bros fork but I don't think he was doing anything custom as far as hub spacing.

 

[sanjuro]

The larger 29 wheels are a lot harder to get off the ground(jump, bunny hop) I do not think it will something that will work out to well for DH.

I am sure we will see some bikes with 29'ers to see if it will work then we will see those bikes fade away like 24's.

I agree. Also the standover and bb height will be higher, another negative.

 

[nmr8]

When he said "custom crowns" I took it to mean wider so you could use the same caliper. This could work with an inverted fork, but a standard fork you would have to cut your arch.
I thought he was talking about an inverted fork?

I thought BCD was using a White Bros fork but I don't think he was doing anything custom as far as hub spacing.

you would definitely have to do more work than just custom crowns to widen the hub spacing, and running an inverted fork would surely be the easiest point to start from.

which makes me think, i wonder if the damping on a 40 would work upside down.. maybe you could make an inverted fork out of it.... cut the drop outs off the casting, and cut the arch off the casting too, then machine two crowns to clamp the lowers, and machine a clamp on dropout for the stanchions. ...voila Fox Dorado..

just broke a rib, i'm a little from the pills.

it makes sense to me, that 29er wheels would have a real advantage on some DH sections, it's just a matter of time before people start experimenting with them more and start to solve the problems.

 

[trailhacker]

I agree. Also the standover and bb height will be higher, another negative.

I can see the stand-over maybe being a lttle different in the headtube area but why would it need to be higher the further back you got?

My only experience with 29r's is my GF has been riding one (Kona HT) since she bought it last fall (has only ridden her Turner 5-spot once all year!) and the owner of the shop has let me ride his around the shop and for short sections when we are out riding (FS and HT). But he will let me take it anytime I want as long as he isn't riding it.
With that in mind, I never noticed a higher BB height? I thought the idea with the 29's is to maintain the geometry as much as possible but compensate for the bigger wheels?

 

[jncarpenter]

With that in mind, I never noticed a higher BB height? I thought the idea with the 29's is to maintain the geometry as much as possible but compensate for the bigger wheels?

Yeah, that was an errant remark. The wheel size has no bearing what-so-ever on bb height.

 

[demo 9]

i personally think that the 26 standard will stay, think about how hard that would be to change... and how many 26ers are rollin out there

 

[dhkid]

isn't there a rule that the uci has about both wheels having to be the same size?

making 69'ers not legal?

could be wrong.

 

[BikerBoy28]

Is 29er Dh inevitable?

 

[DirtyMike]

Personally, to keep the bar height correct on a 59er bike, using normal 7 or 8 in travel forks, you are going to have a rediculously slack bike. I mean being made for this setup, the bike is going to be SLACK.... but hey, it might work for some, but not be something that takes hold. I think its great that some people are out there making customs etups to give it a try, but it just isnt something I see holding up as a possible new standard. xc hardtail and short suspension setups, great they ride awesome, and feel good, but for True DH, I just dont see it being a viable option, not without reinventing the bicycle all together with a whole new set of standard for building a Bicycle.

 

[buckoW]

Weren't people running the stems under the crowns for a lower bar height with the 29" wheels. I don't think bar height or HA will be a problem but it is more adding 1.5" to your chainstays that will be tough. Rims are already fragile enough for a 500 to 600 gram rim so why would we want more rotational weight and increased fragility?