steering response of 29ers- Mtbr.com
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  1. #1
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    steering response of 29ers

    i've been riding my giant 29er and it's felt slow in the steering. bars don't have much cut off from stock (salsa pro moto, i believe they're 17*) and wheels are stock(and heavy). how's the steering on you guys' 29ers. i did ride a friends fs 26er and it felt like it steered a lot quicker.

  2. #2
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    Quote Originally Posted by Cptn. Sense Of Direction
    i've been riding my giant 29er and it's felt slow in the steering. bars don't have much cut off from stock (salsa pro moto, i believe they're 17*) and wheels are stock(and heavy). how's the steering on you guys' 29ers. i did ride a friends fs 26er and it felt like it steered a lot quicker.
    A lot of variables influence "steering feel" HTA, fork offset, stem length, bar width.

  3. #3
    1*14*29*2.1 & 1*1*29*2.4
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    mine feels great, but everything else the same the 29er will proabbly be slower. Not enough to be important IMO. Minimise it with a light front wheel (just borrow one and see if it helps), try a shorter stem etc. A technique often mentioned is leaning the bike more and works for me. This way you don't need to steer so much and the handling is better anyway.

  4. #4
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    I used to have the same problem with mine. I put a 50mm Thompson Stem on it, now it feels like a completely different bike and handles how it should have from the start.

  5. #5
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    They do steer slower. You can alter the angles and stem lengths - but all things being equal, smaller wheels steer quicker. The question you should ask yourself is if it matters to you. Years of riding experience (over 30 if you must ask) have led to smoother riding through technical terrain. Smoother = faster, less flats & less crashes. The bigger wheels take smooth and kick it up a notch. There have been a few occasions where very quick handling & acceleration might have helped - but the balance more often tips towards the smooth confident ride of the big wheels.

    What I would like to see from the wheel industry: Published inertia values. The overall weight of a wheel is less important than how that weight is distributed. There is no getting past the fact that the weight on a larger wheel is spread further out from the axle than on a smaller wheel.

    Go here - use in the same weight rim, then use different inside & outside values for a good example of the difference : http://www.engineersedge.com/motors/...ght_radius.htm

  6. #6
    jms
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    Quote Originally Posted by Self Motivated
    They do steer slower.
    Not all of "them".

    Keep the wheelbase tight [42.5"], the head angle @ 72 degrees with a 44mm offset fork [Fox], keep the seat angle @ 73 degrees or less, don't make the top tube stupid long [24.25 e.l.], chainstays @ 17.5, BB height @ 12.5" and the bike handles "crisply" or better at low speed, and the gyroscopic effect of the large wheels takes care of the high speed stability.

    Just my opinion based on a year + of racing the "damn thing".

  7. #7
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    Please read again: All things being equal, they all steer slower.

    The original post is questioning whether or not 29'rs respond slow. Overall - this does depend on the angles and tube lengths that you refer to. But I guarantee if the same bicycle were fitted with 26" wheels - steering response would sharpen.

  8. #8
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    Yeah, I would say my 29'er steers a little slower than my 26" bikes did. But, and it is a huge BUT, I haven't sacrificed any agility. In fact, my 29'er is more agile under me than my 26" bikes of the past as I am able to ride some things that I was never able to ride on a 26" wheel and do it without drama on the 29'er. My 29'er when rolling at moderate to high speed requires more lean angle than a 26" bike on the exact same corners at the exact same speed holding the exact same line. Makes perfect sense that this is the case with a larger diameter wheel and tire. The 29'er feels like it 'carves' turns more so than the 26" bike.

    So yeah, I think it does steer slower, but I love how it does it.

  9. #9
    jms
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    My comprehensions fine

    Quote Originally Posted by Self Motivated
    Please read again: All things being equal, they all steer slower.
    My comprehensions fine, and I'm not trying to be a contentious dick, but, since the wheels are different sizes, "all things can't be equal", I believe that's where my issue begins, the term "all": I find stereotypes and global statements risky at best, and taste awful when I'm forced to eat my words.

    Bottom line, 29ers can be designed to handle "quick", it is a fallacy that they can't be. I choose not to promote that assumption - and I have a custom frame that refutes the notion. Your results and beliefs may be different.

    No worries either way.

  10. #10
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    Quote Originally Posted by dirtfall
    I used to have the same problem with mine. I put a 50mm Thompson Stem on it, now it feels like a completely different bike and handles how it should have from the start.

    That has to be total BS! That is all in your mind, not in what a simple stem will do!
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  11. #11
    Naturally Organic
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    Doesn't matter.

    You will never ride a 29er & 26er at the exact same time (unless you are a circus freak and/or uber talented...no offense to circus freaks). What does matter is overall ride quality. 29er FTW! If you have a favorite trail, ride it with both. IMO, after doing so, the benefits far outweigh any drawbacks. If you were to do a side by side comparison, yeah, the 26er may win a few columns, but the overall champion, IMO, for most trails and riding conditions, would be the 29er (all things being as equal as possible). To any flamers, I know, I know, there are some trails and rides where the 26er may be advantageous, but for me, they are far and few between.

    Edit: No offense to the uber talented, either...

  12. #12
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    Quote Originally Posted by jms
    My comprehensions fine, and I'm not trying to be a contentious dick, but, since the wheels are different sizes, "all things can't be equal", I believe that's where my issue begins, the term "all": I find stereotypes and global statements risky at best, and taste awful when I'm forced to eat my words.

    Bottom line, 29ers can be designed to handle "quick", it is a fallacy that they can't be. I choose not to promote that assumption - and I have a custom frame that refutes the notion. Your results and beliefs may be different.

    No worries either way.
    The other guy is correct. If you only change wheel size, smaller wheels will handle quicker with the same geometry. A bike with 29" wheels and 26" geometry will handle awful. Same with BMX 20" vs Cruiser.
    Worked at Trek/Fisher dealer 2008-2013. Only a little biased.

  13. #13
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    My two 29ers feel "slower" than my multiple 26" bikes. I don't ride the 26" bikes anymore so I personally am not too concerned about it.

  14. #14
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    Quote Originally Posted by jms

    No worries either way.

    Agreed! But to be a contentious dick (this is getting more like an MIT forum - read one of those for a laugh sometime) - no custom frame in world can overcome the difference in greater angular momentum / inertia and it's resultant torque values (or steering input force required in this example).

    As the laws of physics prevail - I feel a certain freedom in contributing to these generalizations.

    Before someone posts it: DUDES JUST CHILL & RIDE WHAT YOU LIKE!

    PS - I really like my 29r's.

  15. #15
    craigsj
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    Quote Originally Posted by Self Motivated
    no custom frame in world can overcome the difference in greater angular momentum / inertia and it's resultant torque values (or steering input force required in this example).
    That claim is trivially true but so what? You haven't made the case that differences in angular momentum actually matter. How much difference is there? How does that burden the rider? How does that effect steering "quickness"? It should be clear that this is very much application-specific.

    Quote Originally Posted by Self Motivated
    As the laws of physics prevail - I feel a certain freedom in contributing to these generalizations.
    What law of physics tells you that this matters? Which ones prevailed?

    In order to claim that larger wheeled bikes steer slower, you need to show some aspect of the bike's overall geometry that must be different and that unavoidably has that effect. No one has done so here. Larger wheels place more restrictions on how small a bike can be. As long as we are talking about large enough frames, I don't think that generalization is valid.

  16. #16
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    Sure, I guess the bigger wheels handle "slower", but I think a better statement would be "different". As I've transitioned from 26" to 650B to 29" I've had to alter my riding style a bit to take advantage of the different. With the bigger wheels I've had to use some of my rode bike handling skills. I realize that some will say that riding a rode bike doesn't require handling skills, but there are techniques that translate very well. I apex the corners more and, as others have pointed out, lean the bike more. At higher speeds it is easier to counter steer so in sweeping turns you can cary more speed. The point that I have trouble is only on very tight, rutted, uphill switchbacks. If I allow myself to be forced to follow the outside line then I find myself climbing the side of the mountain coming out.

    Sure, ride a favorite trail and you'll notice a difference, but you may also find yourself prejudiced by the lines you've always taken on a 26er. Try a totally novel trail. You won't have any preconceived notions of what lines to take. Flow with the bike. You'll then really appreciate the difference. Vive le difference.

  17. #17
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    Quote Originally Posted by Blazerwolf
    That has to be total BS! That is all in your mind, not in what a simple stem will do!

    Think you are wrong a shorter a stem will help speed the steering just like narrower bars - try it if you are a skeptic .

  18. #18
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    I think a lot of the "slow" feeling stems back to feeling like you're "in" the bike rather than "on" the bike. The bottom bracket of 29ers is ALWAYS below the axle height whereas a 26er will be much closer to it. You'll always feel more on edge when you sit higher up which contributes to the "quick" handling of the 26er.

  19. #19
    saddlemeat
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    Light wheels are quicker handling than heavy wheels. Size usually matters but in this case I doubt it. If I knew enough physics I could prove it.
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  20. #20
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    Quote Originally Posted by Self Motivated
    What I would like to see from the wheel industry: Published inertia values. The overall weight of a wheel is less important than how that weight is distributed. There is no getting past the fact that the weight on a larger wheel is spread further out from the axle than on a smaller wheel.
    I don't think that's going to help, if for no other reason than that the tires on any given wheel will have more effect on the moment of inertia than anything about the wheel itself, which probably means that even a light 29 wheel will have a higher moment of inertia than a heavy 26 wheel.

    My (semi-professional) breakdown of the situation: The moment of inertia may affect acceleration to some significant degree, but the effect on turning is likely to be small in comparison with friction with the ground. The fact that the 29 wheel has greater friction with the ground might come into play, as well as the peculiarities of frame geometry and other occult subjects, but the moment of inertia of the wheel itself should be relatively unimportant.

    A completely different factor might be the extent to which you must lean in order to compensate for a curve; the taller wheels imply an overall higher center of gravity, so you might have to lean further in a given curve at a given speed.

  21. #21
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    Here's a couple of thoughts:

    1- The Giant's come with Kenda Karma's correct? Maybe that tire isn't connecting for you and you're lacking some feedback.

    2- How often do you ride a road bike? Me, fairly often. That steers quick. When I get on my 29er, it feels huge and burly - just a matter of perspective. 5 minutes in and it's like an old leather glove - it just fits. I classify the handling (on my Karate Monkey) as intuitive. Not quick, not slow, but easy to point it exactly where I want to go.

    3- Does the handling of your bike induce fear or hold you back? Does it prevent you from accuracy on the trail? If not, than it's probably really neutral, which can be a good thing in the long term.
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  22. #22
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    Quote Originally Posted by Self Motivated
    They do steer slower.
    No - not all 29ers, because there are of course differences in the frame/fork geometry.
    My Karate Monkey steers much quicker than my old 26" did.
    A Speci 29er I tried, steered definitely slower than my KM.

  23. #23
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    Quote Originally Posted by jms
    ...and the bike handles "crisply" or better at low speed, and the gyroscopic effect of the large wheels takes care of the high speed stability.
    This is excactly what I feel on my Karate Monkey. At low speed I can drive extreme small circles - but at high speed it runs thru the forest like a freight train

  24. #24
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    What tire are you running ???

    Try a Bonty 29-3 2.25 the tread pattern really quickened my steering up speed and response wise.

    The shorter stem only quickens up the steering, because there is less weight on the front wheel the same less weight will make the front end go all over the place when it gets muddy.

  25. #25
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    Wide bars

    I think the general trend for the wide bars is a problem for 29ers. Took off the 27 or 28" riser that came on my bike and went back to a standard 580mm, and all the sudden I had my cross country bike back. Don't need a big bar for control with the big wheels, let them do their work. Wide bars are good for big tall guys who need to breathe and climb better. And man, those Giants come with Barbells! Cool bikes, but man, I can't help but think how much better it would handle with a more standard bar. Still not going to be as fast, since when you turn you break the opposite way first, and it feels a little sluggish then, but it is still a clean, gliding ride that doesn't fall off in the rough. After I ride my 26er, my 29er actually feels like it accelerates in the roughs and I appreciate that!

  26. #26
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    I have to agree with this because....

    Quote Originally Posted by jms
    Not all of "them".

    Keep the wheelbase tight [42.5"], the head angle @ 72 degrees with a 44mm offset fork [Fox], keep the seat angle @ 73 degrees or less, don't make the top tube stupid long [24.25 e.l.], chainstays @ 17.5, BB height @ 12.5" and the bike handles "crisply" or better at low speed, and the gyroscopic effect of the large wheels takes care of the high speed stability.

    Just my opinion based on a year + of racing the "damn thing".
    living in the NE and after riding all over the country I realized that where I live and ride is much tighter than just about anywhere else that I have been. So I had Ted Wojcik build me a 29er frame designed for where I live and ride. Point and shoot steering is a must here. My frame has a lot in common with the design suggestions mentioned above. You would have to ride it to believe how quickly it steers while still being very stable. For reference, all I rode were steel ht 26ers with racing geometry prior to this (2 Voodoo Bizango's, a Norco Team issue, a Custom Curtlo 24hr, a Jamis Dragon). None of them have anything on my Ted, its a much faster bike as well.
    Last edited by edouble; 08-18-2010 at 06:23 AM.
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  27. #27
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    Quote Originally Posted by codejack
    I don't think that's going to help, if for no other reason than that the tires on any given wheel will have more effect on the moment of inertia than anything about the wheel itself, which probably means that even a light 29 wheel will have a higher moment of inertia than a heavy 26 wheel.

    My (semi-professional) breakdown of the situation: The moment of inertia may affect acceleration to some significant degree, but the effect on turning is likely to be small in comparison with friction with the ground. The fact that the 29 wheel has greater friction with the ground might come into play, as well as the peculiarities of frame geometry and other occult subjects, but the moment of inertia of the wheel itself should be relatively unimportant.

    A completely different factor might be the extent to which you must lean in order to compensate for a curve; the taller wheels imply an overall higher center of gravity, so you might have to lean further in a given curve at a given speed.
    I like this. Nobody has mentioned that the contact patch is bigger (longer) than that of a 26". Ima n00b so Im not gonna try to argue w/ you guys, but I thought this would be a considerable factor. Ive been enjoying this thread since I took my new 29er out for the first time the other day and noticed a little slower handling characteristic.

  28. #28
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    Quote Originally Posted by Self Motivated
    What I would like to see from the wheel industry: Published inertia values. The overall weight of a wheel is less important than how that weight is distributed. There is no getting past the fact that the weight on a larger wheel is spread further out from the axle than on a smaller wheel.
    I'm not entirely sure that's true. It's undoubtedly true for a free spinning flywheel (or a wheel that's slipping) but, I believe, not for a wheel in contact with the ground. In that case only the total mass counts.

    There's wiki article here which seems to back me up... http://en.wikipedia.org/wiki/Bicycle_performance

    I'm quite happy to admit I could easily be wrong. It would be nice to hear what some of the more techy posters think.

  29. #29
    craigsj
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    Quote Originally Posted by nuffink
    I'm not entirely sure that's true. It's undoubtedly true for a free spinning flywheel (or a wheel that's slipping) but, I believe, not for a wheel in contact with the ground. In that case only the total mass counts.

    There's wiki article here which seems to back me up... http://en.wikipedia.org/wiki/Bicycle_performance

    I'm quite happy to admit I could easily be wrong. It would be nice to hear what some of the more techy posters think.
    You are right. A larger wheel has a higher mass moment of inertia but it spins slower and the two cancel out. All that matters is the overall weight and the distribution of that weight as a percentage of overall wheel diameter.

    I ran some fairly careful estimations of road and MTB wheels of different sizes and the weight distribution didn't change much. All were within a few percentage points centered around 70%. That may be somewhat different for outliers, like DH wheels, but I doubt it.

    Because wheels of similar construction have a similiar distribution of weight, all that matters is how much weight there is. A 29er wheel that is lighter than a 26er wheel has less rotational inertia despite people's intuition to the contrary.

  30. #30
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    I swap between 26" okay RQ 2.4 and a 29" Ardent 2.4 depending on what I'm riding and despite the 1.5ish degree angle change I really don't notice a speed difference.

    But with 29-3's fitted, it steers much faster and more direct and the FR3's it really is hard to turn and the opposite.

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