Has anyone tried a 29er front on their DH??- Mtbr.com
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  1. #1
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    Has anyone tried a 29er front on their DH??

    I was curious if anyone has tried a beefed up 29er wheel on the front of their DH rig, kind of how they do it in Motocross with the 21" in front and 18/19" in the rear??

    Obviously it would change your head angle a few degrees, and you'd have to have a clearance forgiving fork.

    Post some pics or comments....

  2. #2
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    Didn't BCD play with this? 29er DH bikes.
    Nothing good here.

  3. #3
    Rb
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    No, and I never will.

  4. #4
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    Nmw
    Last edited by combatkimura; 12-14-2008 at 06:31 PM. Reason: It was not constructive to the thread

  5. #5
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    strong feelings there....i agree!!!!!
    Quote Originally Posted by [Orge
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    This problem could quite simply be solved if people would stop buying Konas.

  6. #6
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    i saw a while back on ridemonkey some dude dremeled his fox forty to fit a 29er wheel.what a retard he ruined a 1600$ fork so he could have more rotational weight and worse turning.

  7. #7
    StraightOuttaCompton
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    there aren't enough advantages to do it. Other than rolling over stuff, i can't think of one advantage. But if you are having hard times rolling over rocks, roots, etc., then go faster.
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  8. #8
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    Quote Originally Posted by matthew4president
    i saw a while back on ridemonkey some dude dremeled his fox forty to fit a 29er wheel.what a retard he ruined a 1600$ fork so he could have more rotational weight and worse turning.
    He also took 26th in Pro on a home built carbon DH bike at angle fire. He's also played with numerous setups for gearbox bikes, some of which are being used now days (although I'm not claiming he's the sole originator). The dude is a pioneer, a super nice guy, and there's no need to sh!t talk him.

    I'm not advocating everybody use a 29er wheel, but there are advantages and disadvantages. But seriously, if you don't believe me, why don't you go back to riding your 24 inch 2001 huck bike.

    Why are you so incredibly against things you don't understand? My god...

  9. #9
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    I know crazy idea's have never proved to possibly work, right? Like who in their right mind would put two shocks on the rear? That type of thinking would never lead to any innovations....

    If a benifit is "going over things" faster and more easily, who in their right mind looking to go faster and improve their sport would not try it. Props to the industry pioneers and those who are trying to think outside the box.

  10. #10
    StraightOuttaCompton
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    that is true, just they would have to find a way to make the wheels just as stiff without a weight penalty.
    HARDTAIL PRIDE- 09 Kona Five-0

  11. #11
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    if they can make bigger wheels bigger and same weight why carnt they just make 26" lighter and stronger? its the same principle
    Quote Originally Posted by [Orge
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    This problem could quite simply be solved if people would stop buying Konas.

  12. #12
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    Quote Originally Posted by Djponee
    there aren't enough advantages to do it. Other than rolling over stuff, i can't think of one advantage. But if you are having hard times rolling over rocks, roots, etc., then go faster.
    What about larger contact patch and increased traction? I guess if you're having trouble cornering you should go faster.

    Seems like people are pretty quick to bash ideas they haven't really thought about with any sort of depth.

    Here's Alex (aka BCD) on his 29er homebuilt carbon bike. What a dirt roadie. His wheel size has no inherent advantages and carbon should never be used on a downhill bike, amiriteguys?


  13. #13
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    Rigid 29ers are for roadies too! Oh no, looks like someone is gonna punch me in the nuts and knee me in the face.


  14. #14
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    Quote Originally Posted by nouseforaname
    Didn't BCD play with this? 29er DH bikes.
    Yep, looks that way: http://bcdracing.com/psycho-billy-cadillac/inedible.htm

    I think that a 29 on the front is so valid, I'll make a prediction that in a few years, most DH rigs will have 29" fronts. The physics all support it, and the common sense aspect makes sense too.

    I would be willing to say that the industry is not jumping all over it right now, because they need to get the design, R&D and tooling built up to make it happen. I bet they are doing a ton of in house testing though. Test it out on the cyclocross and xc people, see where problems lie, and integrate it into the rest within 3-5 years.

    Oh, and a larger brake rotor would also make sense to arise from the industry. 9-10 inch seems huge, but would make sense with a larger wheel/tire.

    Does anyone make a beefy 29" front w/ 20mm?

  15. #15
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    Quote Originally Posted by E_braker
    Yep, looks that way: http://bcdracing.com/psycho-billy-cadillac/inedible.htm

    I think that a 29 on the front is so valid, I'll make a prediction that in a few years, most DH rigs will have 29" fronts. The physics all support it, and the common sense aspect makes sense too.

    I would be willing to say that the industry is not jumping all over it right now, because they need to get the design, R&D and tooling built up to make it happen. I bet they are doing a ton of in house testing though. Test it out on the cyclocross and xc people, see where problems lie, and integrate it into the rest within 3-5 years.

    Oh, and a larger brake rotor would also make sense to arise from the industry. 9-10 inch seems huge, but would make sense with a larger wheel/tire.

    Does anyone make a beefy 29" front w/ 20mm?
    You could. Lace up a 29er rim to a 20mm hub.

    Anyway, there are disadvantages - wheel's aren't as stiff, they weigh more, and a bigger wheel is gonna need a bigger tire (more rotational weight). Changing the wheel's direction is harder as well. Really digging the bike over in corners is harder, and sizing is more difficult. I don't know if it's gonna sweep the industry, since strength and weight are quite significant, and its tough to sell bikes when sizing is extremely specific (with mtb's anyway, its why you see so many companies that sell a "small" and a "large" size for their DH bikes).

    I don't think its a dumb idea, its just not right for the trails I ride and the cost is prohibitive for now. I'd like to ride one though!

  16. #16
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    also, its not just wheels, we need the forks too

  17. #17
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    i think perhaps a 650b wheel on a DH bike would be a good option. Better bump and obstacle compliance but without the lethargic steering of a 29'er.
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  18. #18
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    What's next, skinnier tires? shaving legs?

  19. #19
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    errrrr NO!
    Quote Originally Posted by [Orge
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    This problem could quite simply be solved if people would stop buying Konas.

  20. #20
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    Quote Originally Posted by Luigiugueto
    What's next, skinnier tires? shaving legs?

    Semi slicks and sub 4 inch travel bikes

  21. #21
    SamIAm
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    if they made the spacing larger than 110mm* thats what it is, right? like say 135/150 then the wheel could have the same angles/dish etc as a 26.
    you could run a highpressure/smaller tire up front and it would still have a larger contact patch, so that shouldnt mess up traction, right?

    i dont think i could ever see a 29rear tho, i dont think there would be a feasable way to make it fit with proper geo unless it was made just for peaty-sized peeps, and then it would just get alot heavier to keep it the same strength, you would need to increase spacing, 180m+, then wider cranks, etc....just doesnt add up.
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  22. #22
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    Having a 29er xc bike and riding downhill I can say there are definate advantages to the 29er "fad" (its not going away imo) the contact patch ,the wheel arc, the slow turning that is associated with 29ers comes from early versions without corrected geometry. They turn killer and hold a line very well. And on an XC or even a trail AM type bike I think a 29 would be the ticket. I would not want to trade my 26 inch DH in though. Wheel strength/stiffness is an issue for sure. I could only imagine trying to sprint or even pedal a 29 DH rig with a 4 ply tire. There is no doubt 29ers role over obstacles with a noticable difference, but most 29 tires are smaller xc type. Compare your big 2.75 or larger DH tire and your overall wheel dia is not that different. Not to mention how much longer those chainstays will have to get. Thats my 2 cents

  23. #23
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    Quote Originally Posted by Ojai Bicyclist
    Rigid 29ers are for roadies too! Oh no, looks like someone is gonna punch me in the nuts and knee me in the face.

    I would and could roll that on a carbon road bike.

    I know I'm a little harsh with my words but there are just things that don't make sense. A big noodle of a wheel with higher rotational weight and gyroscopic forces doesn't make sense on today's tight and technical DH courses. If all races are moved to long fireroads with large radius sweeping turns then I could see people using 29" wheels but until that happens...nope.

    I'm all for innovation and progress but 29" wheels an a DH bike just doesn't make sense to me. 26" seems to be pretty damn perfect.

    Ojai, let me know where to meet you for that one-two combo .

  24. #24
    gnar, brah
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    It will never happen. 29ers are allergic to berms.

    I have tried this as scientifically as I could. I had a 20" BMX bike, two different 26" dj/slopestyle bikes, my rigid 29er, and a buddy's pump track, complete with lights for all-night "experimentation".

    The results? 20" did the best job of going where you pointed it, predictable steering, but required outrageous effort to pump the terrain. Even just two or three laps was exhausting, and the uphill section very difficult to ride smooth. When it was going good it felt like a damn slot car.

    The 29er was very fast around the track, but was almost impossible to pump the terrain, speed was derived from the cranks only, which is not the way DH races are won. Berms were the most problematic, as the 29er does not like to get sideways. My reasoning is the axles are higher, so the CG is higher, and aggressive cornering suffers.

    The 26 inch bikes were the perfect compromise of pumpability, speed, and handling. They were the fastest and most fun bikes to ride on the pump track. This applies on DH trails too. I took my 29er down the mountain on a DH trail...not recommended. Don't get me wrong, they are great bikes with their own virtues, but they were built for a different type of shredding.
    Trestle Bike Park

  25. #25
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    Quote Originally Posted by Andrewpalooza
    It will never happen. 29ers are allergic to berms.

    I have tried this as scientifically as I could. I had a 20" BMX bike, two different 26" dj/slopestyle bikes, my rigid 29er, and a buddy's pump track, complete with lights for all-night "experimentation".

    The results? 20" did the best job of going where you pointed it, predictable steering, but required outrageous effort to pump the terrain. Even just two or three laps was exhausting, and the uphill section very difficult to ride smooth. When it was going good it felt like a damn slot car.

    The 29er was very fast around the track, but was almost impossible to pump the terrain, speed was derived from the cranks only, which is not the way DH races are won. Berms were the most problematic, as the 29er does not like to get sideways. My reasoning is the axles are higher, so the CG is higher, and aggressive cornering suffers.

    The 26 inch bikes were the perfect compromise of pumpability, speed, and handling. They were the fastest and most fun bikes to ride on the pump track. This applies on DH trails too. I took my 29er down the mountain on a DH trail...not recommended. Don't get me wrong, they are great bikes with their own virtues, but they were built for a different type of shredding.
    So let me get this straight:

    Since 29ers don't work as well on pump tracks, and your rigid 29er doesn't like DH trails, DH 29ers will never work?

    I understand what you're saying (to a point) but it seems like the only real way to tell if 29ers are viable would be to build a 29er DH bike.

  26. #26
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    Didn't we go through this exact thing several years back with 24" wheels? That was the "Next Big Thing" circa 2000...
    Desert Sunset Calls/Upward, Pain, Perseverance/Welcome Solitude

  27. #27
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    Quote Originally Posted by Ojai Bicyclist
    Rigid 29ers are for roadies too! Oh no, looks like someone is gonna punch me in the nuts and knee me in the face.

    what alot of people don't realize is that the bike in the pic is a fixed gear and he is riding up the wall backwards. Insane brutha.

  28. #28
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    think how far freeride and downhill bikes and parts have gone in 10 years. hard to tell what the next 10 may bring

    :P

  29. #29
    gnar, brah
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    Quote Originally Posted by Ojai Bicyclist
    So let me get this straight:

    Since 29ers don't work as well on pump tracks, and your rigid 29er doesn't like DH trails, DH 29ers will never work?

    I understand what you're saying (to a point) but it seems like the only real way to tell if 29ers are viable would be to build a 29er DH bike.
    I'm jumping to conclusions a bit, sure, but the differences in the character or essence of the bike between 26 and 29 leave me with a feeling that the 26 is just an inherently better tool for the job. If you could build a strong enough wheel, I think a 29er might be faster through rock gardens, but I just don't feel that I like the characteristics of the bigger wheel in faster, bermed-out trails, especially with jumps. I've never ridden a 29er DH bike, because only one or two exist, but I don't think I'd like it.
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  30. #30
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    you know what, this is a SPANDEX moment, and i am really drunk so stop riding 29" because it will make you gay like the ****** on Sopranos season 6

  31. #31
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    It is impossible to do a real test because there are no existing DH 2ply tires to test with.

    Alex/BCD dremeled the lowers of his 40 to fit the 29"wheel. That is not so ridiculous because cost on a set of lowers is under 200 bucks. Guy is a forward thinking genius touching subjects that scare most people and then guinea pigging that **** himself and getting decent race results. Props to him.

  32. #32
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    Quote Originally Posted by William42
    He also took 26th in Pro on a home built carbon DH bike at angle fire.

    Why are you so incredibly against things you don't understand? My god...
    I don't care how nice a guy he is or how fast he goes down hills. What he did to that 40 was downright dangerous. Cut off half the arch! The best bit is, the back of the arch is webbed, and by cutting off the flange at the bottom he made some huge stress risers. Read somewhere he is selling these 'modded' 40's, I really hope someone isn't injured when one fails 'cos he'll get raped.

  33. #33
    Ricky DH
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    Quote Originally Posted by kenneththecurtain
    I don't care how nice a guy he is or how fast he goes down hills. What he did to that 40 was downright dangerous. Cut off half the arch! The best bit is, the back of the arch is webbed, and by cutting off the flange at the bottom he made some huge stress risers. Read somewhere he is selling these 'modded' 40's, I really hope someone isn't injured when one fails 'cos he'll get raped.

    Fox just come out with a "memo" stating that people shouldn't be doing that to the 40 forks.

  34. #34
    Ricky DH
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    Oh, here we go. From the Fox web-site.

    WARNING

    It has come to the attention of FOX Racing Shox that certain individuals and / or entities are modifying FOX forks to accommodate mountain bike wheel sizes other than those having 26 inch nominal diameter. One such modification includes removing material from the lower leg cross bridge in order to fit a 29 inch tire in the fork. Such modification will ultimately separate the lower fork legs at the cross bridge (i.e. the weakened cross bridge will fracture) and may cause bicycle instability and crash that result in SERIOUS INJURY OR DEATH.

    DO NOT MODIFY OR MISAPPLY FOX FORKS

    NEVER REMOVE MATERIAL from any portion of a FOX fork. USE ONLY 26 INCH WHEELS with FOX 32*, 36 and 40 bicycle suspension forks. Those FOX forks are designed and tested for use ONLY with 26 inch Mountain Bike wheels / tires. Use of FOX forks with any wheel other than 26 inches and/or alteration or modification of any FOX fork will subject the FOX fork to loads and forces it has not been designed or certified to meet and will void all warranties. The FOX 32*, 36 and 40 models meet CEN and ASTM testing standards ONLY when used with 26 inch wheels / tires and are not recommended or approved by FOX Factory, Inc. for use with wheels larger or smaller than 26 inches, either as original equipment or aftermarket.

    DO NOT RIDE ON MODIFIED OR MISAPPLIED FOX FORKS

    Proper forks are critical to proper bicycle handling and stability. Improper function or failure of a bicycle fork while riding can cause a bicycle to become uncontrollable and result in a crash. Use of FOX 32*, 36 or 40 forks with wheels larger or smaller than 26 inches, or any other modification, may cause crashes that result in SERIOUS INJURY OR DEATH. Never ride a bicycle that is, or appears to be, fitted with a FOX 32*, 36 or 40 fork that has been modified and / or fitted with any wheel larger or smaller in nominal diameter than 26 inches.

    * DO USE THE RIGHT FORK FOR THE JOB

    For those of you who want to ride on 29 inch front wheels with suspension, FOX offers the 32 F29 fork designed specifically for 29 inch wheels. The F29 is available in 80mm, 100mm or 120mm travel configurations and is ideal for tall wheel applications. The F29 is the only FOX fork available for use with 29 inch wheels and is clearly labeled "F29" on the right leg. The F29 should be used only with 29 inch wheels. As with all FOX forks, do not modify or misapply, or ride on improperly applied or modified FOX F29 forks.

    DO CONTACT FOX

    Do not modify any portion of a FOX fork and do not purchase or use any fork that appears to have been modified. Any FOX 32*, 36 or 40 model fork that appears to accommodate a tire larger than 26 inches in nominal diameter, such as 650b or 29 inch, should be avoided. If any doubt exists as to the originality or proper application of a FOX fork please contact a FOX representative.

    Thank you,
    FOX Racing Shox

  35. #35
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    Nsfd
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