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New bigger wheels craze

Discussion in 'Downhill & Freeride' started by Kntr, Sep 19, 2012.

  1. Kntr

    Kntr Turbo Monkey

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    Ok, I'm hearing guys trying 26" rear wheels and 27.5" and 29" front wheels. What is up? Are people really trying this?
     

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  2. Sandwich

    Sandwich Pig my fish!
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    ha! not here, that's for sure.

    plus you have to have a pretty specific fork in order to be able to run a 650b, and an even more specific fork with less travel to run a 29er.

    I run a 650b trail bike now, after trying a 29er trailbike before. 650b feels like cheating without the sluggishness and design constraints of 29ers. It's only a lowly trailbike, but I'm hoping to take it to highland or burke mtn at some point.

    I expect it'll be a while before 650b catches on for DH, if it does. Most people don't want anything different unless it comes from their favorite manufacturer or teh carbonz. I don't think 29ers will ever be suitable for anything more than an experiment with a DH bike. The design constraints are just to great, even though I think you could eventually get the wheels to work.
     
  3. quintonspauldin

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  4. dfinn

    dfinn Turbo Monkey

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    but would you be riding that if they weren't giving it to you for free?
     
  5. Dogboy

    Dogboy Turbo Monkey

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    Between Eurobike and Interbike I've counted 17 companies doing 27.5" bikes for 2013. I'm sure I missed a few and there are lots of other companies that plan on doing bikes but haven't shown them yet. Yes, it is real.
     
  6. Pslide

    Pslide Turbo Monkey

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    I would think that's not a very bright idea. Different diameter wheels have different cornering radii for any given lean angle. You've got your front tire trying to do something different from the rear tire. In theory at least.

    There's a reason the original 69ers didn't catch on...
     
  7. chillindrdude

    chillindrdude Turbo Monkey

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    My next AM/enduro bike will be a full carbon 650B. Yeah i drank the koolaid..
     
  8. stumpjump

    stumpjump Monkey

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    F'in doctor Koolaid over here....
     
  9. gemini2k

    gemini2k Turbo Monkey

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    I feel like I've almost never heard anyone (who has a clue about life and/or bikes) "Gee, I wish my bike rolled over rocks better". But almost everyone says "I wish I could turn better" or "I wish I could muscle my bike around better". And 650b or whatever stupid big wheel trend is next does nothing to address any of the actual concerns of DH bikes.
     
  10. Sandwich

    Sandwich Pig my fish!
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    #10 -   Sep 19, 2012
    Last edited: Sep 19, 2012
  11. Carcinogen

    Carcinogen Chimp

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    What about the old bighits with 24/26 wheels? I don't seem to recall them cornering horribly, but I haven't spent much time on one in a while.
     
  12. tabletop84

    tabletop84 Monkey

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    Shouldn't at least the 40 and the 888 work with 650b? And a few existing frames should also work if you have variable chainstays and enough clearing space. You could even get the geo back to where it was with an angle set and offset bushings. The only question is if it's worth the effort.
     
  13. Sandwich

    Sandwich Pig my fish!
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    I still don't see how having a larger contact patch between your bike and the trail surface won't make you 'turn better'. Don't get me wrong, I think there needs to be a lot of D before big wheels hit DH bikes in force, but I still fail to see where having more traction is a bad thing. Bigger wheels allow for less travel allows for better sprinting allows for more reactive suspension tuning allows for higher air pressures allows for less rolling resistance.....

    I think the negatives are largely in the practical application, like finding a hub width that supports strong wheels, finding rims that balance strength and weight, finding tires that maximize the fundamentals of a larger contact patch, designing a bike that doesn't handle like a school bus....
     
  14. gemini2k

    gemini2k Turbo Monkey

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    Suspension linkage and geometry needs to be completely re-optimized. You also need to learn how to readjust to the new dynamics and geometry. I say no thanks to that.
     
  15. atrokz

    atrokz Turbo Monkey

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    umm hmmm....
     
  16. Sandwich

    Sandwich Pig my fish!
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    did you read anything I've said, ever?

    bigger contact patch from larger wheels good.

    long chainstays from larger wheels bad.

    It's going to take a lot of R+D, mostly D, to figure out how to compromise the two in order to get them to feel "natural". It doesn't have to feel like a 26" bike, just comfortable enough to be fast.

    650b is one compromise that I think has a lot of merit. It allows you to keep the short chainstays that keep a bike feeling "spritely" but gives you some benefit in wheel diameter.

    I personally don't have the cash to bother with a 29er DH bike experiment, but I'd love to try. In the meantime, you'll see more and more 650bDH bikes coming out, despite your objections.
     
  17. atrokz

    atrokz Turbo Monkey

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    My Objections? I wrote two non-words. hahahaha.

    The reason they handle like busses is there is more at play where handling is concerned, than just a long chainstay. They have a higher tip in point to achieve the same lean angle, have more wheel flex, are heavier, and as a result have a higher gyroscopic force. These minor details all play into why 29's are 'slower' to corner. Also why a 20" BMX will out corner a 24" bike, which is easier to spin and turn than a 26" bike, and so forth and so forth. This in undebatable unless your business card says 'head of marketing' on it.....

    But, they DO roll faster and smoother, which is why I think a team like Scott is trying out 650B's. This is something that makes sense for faster courses, and I'm also interested in where this heads and what teams will try it out. I mean, we've been hearing rumours for a few seasons now that Special-ed/monster was testing 29's, as well as other teams, but nothing has come from it, and that may be because 29's just don't cut it. But 650b *could* be the best comprimise. Time, and results, will tell.
     
  18. boogenman

    boogenman Turbo Monkey

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    I was going to say that this thread is going to go full retard as soon as tabletop84 posts but he beat me to it.
     
  19. boogenman

    boogenman Turbo Monkey

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    KHS, Scott and Intense have all shown off 650b DH bikes. I am sure a handfull of the top WC guys will be tooling around on 650b DH bikes in the off season to see if they are worth it.
     
  20. RoboS

    RoboS Chimp

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    "bigger contact patch from larger wheels good."

    Wrong. Contact patch is given by tire pressure, not by wheel size. Wheel size can alter shape of the patch. For 29" wheel it's longer and narrower, but the patch area is the same.
     
  21. Sandwich

    Sandwich Pig my fish!
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    I honestly wonder if it'll be worth a damn, and I think it'll be pretty telling if they decide to stick with them. People are still gobbling up $4000 DH frames year after year. The comparison between a 2001 DH bike and a 2011 DH bike are relatively minor in specifications (aluminum, coil sprung, 8-9" of travel) but the refinements have been huge. I don't know if the "different wheels to sell more bikes" argument holds in the world of DH, where every year we have a different head angle and suspension patent. If those guys still use 26" to race, then eff it!
     
  22. rockofullr

    rockofullr confused

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    AW YEAH!
     
  23. Kntr

    Kntr Turbo Monkey

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    The intent of this thread was different front and rear wheels sizes not the dreaded 29r and 650 and 27.5 and and and and...

    I read on another forum that a few guys have been running 26/29 and 26/27.5 combos and liking it. I had a 24/26 Big Hit back in the day and liked it. Heck I even ran dual 24s and 3.0s for a bit.

    Im sure no one that has tried the 26/29 or 26/27.5 combo will speak up now. :)
     
  24. tabletop84

    tabletop84 Monkey

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  25. Sandwich

    Sandwich Pig my fish!
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    You are correct, but that's not necessarily a bad thing. Less rolling resistance and better braking, for one. It also opens up some possibility of more strategic tire design, with specific knobs and channels for cornering vs. straight line. Again, R+D to prove whether it's worth a damn or if it's MTBR-speak.

    I ran a 24/26 back in the day on my brooklyn and it worked OK. I had a lot of problems with "wheel flop", but the avy fork I had carried a ton of offset (+65?). I didn't notice a dramatic change in cornering strategy when switching from equal sized wheels to different ones, although there did seem to be a large rearward weight shift. I don't know that I would bother with it again if I had my druthers.

    I don't think you'll see any kind of valid info anytime soon though. There are no DH rims on the market for 650b, and no dedicated DH tires. The only thing that comes close is a stan's flow or P35, in 650b or 29er. Then there's the lack of any tire remotely DH worthy. I have a pair of neverrolls, but they're kevlar beaded. I can't see why anybody would give up a tire like a DHF in 2ply for a single ply neve, for anything besides "I wonder what would happen if..." experiments.
     
  26. Pslide

    Pslide Turbo Monkey

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    There's some bad info in this thread, but this horse is so dead...
     
  27. motomike

    motomike Turbo Monkey

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    All I know is that I rode a Yeti SB95 this morning and it did not suck. First time I can actually say that with a 29er. It wasn't mine and I'm sticking with my SB66, but dang it felt good!
     
  28. marshalolson

    marshalolson Turbo Monkey

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    the miss-matched wheel thing never really caught on in XC land either. see trek 69 and carver bikes.
     
  29. time-bomb

    time-bomb Monkey

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    I've run 24/26 before but only on my "mini-dh" bike (7" rear + 6.25" single crown fork). It wasn't practical for general trail riding and it wasn't practical for full on DH either. It was very specialized (but not a Specialized). It was awesome for fast flowy DH tracks that didn't have a lot of big chunk. It lowered the BB and slackened out the bike and that was huge because I didn't have the option of running an angle set on that frame either. I will say that going from 26/26 on that bike to 24/26 it made it feel smaller and more playful. It was a lot of fun to ride in the 24/26 set up when the right opportunity arose. It will work for some people in certain circumstances but probably not practical for "all of the time" (but then again, that depends on the bike).
     
  30. Huck Banzai

    Huck Banzai Turbo Monkey

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    How is that correct? if a 26 and a 29 have the same width tread on them, how is the 29" contact not bigger? Same width, longer patch.

    What am I missing?
     
  31. no skid marks

    no skid marks Monkey

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    Double 24 was mad fun, taught me heaps fast. 24/26 and I'd imagine any other combo is/feels kooky. Front wheel feels all flip floppy, and rear axle tries to match the fronts height when descending or breaking, making it want to overtake the front any way it can. That's what it felt like to me anyway.

    29er will be a thinner longer contact patch for the same pressure(and tire build).
     
  32. Huck Banzai

    Huck Banzai Turbo Monkey

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    Again, if the tire casing/tread is the same width, how is it physically possible that it have a thinner contact patch? Longer? yes, thinner? how does increasing the diameter have any subtracting effect on the width of the contact patch. That just doesn't make sense to me.

    Not based on what tires you have available, but assuming same details excepting diameter.
     
    #32 -   Sep 19, 2012
    Last edited: Sep 19, 2012
  33. Sandwich

    Sandwich Pig my fish!
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    http://forums.mtbr.com/29er-bikes/summary-26-vs-29-contact-patch-pinch-flats-143544.html

    I didn't buy it at first either, but I guess it's true. Still though, there are other advantages. Less rolling resistance with equal pressure. You could lower the pressure and get significantly more contact patch with equivalent rolling resistance. Less tire deflection could change the way tires are built (and therefore their weight). I believe you could design a more specific tire for an intended purpose.

    I'm not saying that it'll be worth it in the end, but I definitely think it would be an interesting experiment, and I think with the right mindset, one closer in line with BCD's than the pinkbikers of late, you could come up with some fast results. I don't think you can slap 29" wheels on a 951 and start winning races, but with enough capital and time, somebody like Scott or Trek could design some pretty interesting stuff.

    Keep in mind that no matter what, manufacturers still win, whether you buy 26" DHFs and 823s or flow 650bs and some strangely named schwalbe tire.
     
  34. kidwoo

    kidwoo Celebrating No-Pants Day

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    mmmmmm.....not really.

    They maintain momentum better. Not exactly the same thing. They accelerate slower (along the lines of everything you just said about 20" vs. 24" when dirtjumping).

    I've been riding a 29er trail bike for a while now (no I didn't buy it) and here's the one single raddest, most awesomest, bitchinest thing ever that no one seems to mention.

    You know jeeps? Like old CJ style? Short wheelbases = better equivalent clearance

    bigwheel.jpg

    Unfortunately, everything else about them completely sucks but that part is rad :D


    You guys talking 'more traction' yadda yadda.......have you actually ridden these things? The tire selection is absolute shlt! How in the world would you know about traction unless you're normally riding something horrible like maxxis ardents on your comparison smaller wheeled bike? I can't stay on the damn trail with the current selection of 'aggresive treads' available for 29" wheels.

    edit: whoa....jesus put slashes in my post every time there's an apostrophe....weird.
     
    #34 -   Sep 19, 2012
    Last edited: Sep 19, 2012
  35. Udi

    Udi RM Chief Ornithologist: “I Brake for Birds”

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    He's mad that Gwin crashed, feel his wrath.
     
  36. kidwoo

    kidwoo Celebrating No-Pants Day

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    shlt I thought he MADE him crash for insubordination of some sort
     
    #36 -   Sep 20, 2012
    Last edited: Sep 20, 2012
  37. Huck Banzai

    Huck Banzai Turbo Monkey

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    I high center my V10 all the time, but fortunately I have a hi-lift jack, so no 29's required.
     
  38. no skid marks

    no skid marks Monkey

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    The full width of the tyre doesn't touch the ground at once. Only say 1/3rd is touching the ground at one time, unless you run 5 PSI. The tyre will deform due to the weight on it at contact with the ground the same amount, on a bigger wheel, the tyre can more easily deform length wise, so there's less width put down. I'm sure tyre casing make up could change this to an extent, but that's an unknown quantity for now.
    Tyres are still pretty round shaped underneath where they touch the ground, unless of cause the air pressure is low enough for the whole width of the tyre to touch at once.
    Rim width may also make a difference to contact patch, but also probably a trivial amount.
     
    #38 -   Sep 20, 2012
    Last edited: Sep 20, 2012
  39. atrokz

    atrokz Turbo Monkey

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    Yea that's pretty much what I mean. They 'roll better' could be construed as 'rolls over things better'. So, yea. :thumb: