650b MTBs revisited...

[rice rocket]

I know this comes up every couple months...

I'm a small rider, 5'6, and I've got a Trek 29er singlespeed right now, and I have some issues with wheel flop at low speeds. If I add more than a little bit of steering, I get wheel flop, or what is known as "chopper flop", since it's common with chopper motorcycles with really shallow head tubes. I don't understand the physics of it entirely, but basically the bike literally falls over.

I only have about a year of MTB riding experience, but this seems to be an issue that I feel is holding me back. Will I get faster on technical trails (of which there are many in my immediate area) to that point that this becomes irrelevant?

Are other 29er frames less prone to wheel flop? I know Trek touts their G2 geometry (shallow headtubes, more fork rake/less mechanical trail, short chainstays) as better handling at low speeds, but I'm not feeling that.

Is 650b the answer? I don't know much about them except whatever marketing speak has been associated with them. "Handles like a 26, clears obstacles like a 29" is usually what's stated. Does that mean less wheel flop? Riding singlespeed, being able to clear stuff easily would definitely be a plus.

Sorry, I've got a million questions, with little basis for comparison.

[juanj]

I am by no means an expert, but I've been riding mountain bikes for a long time, and I'm short like you.

The answer to your first question is yes, you will improve your skills and become faster, and the problems you are having with wheel flop will diminish.

But the question still remains, are you better off with a smaller wheeled bike, such as a 650b? I think yes, for shorter people, the 650b makes sense. Many people will tell you that shorter bikers can ride 29ers, and they will point to recent world cup victories had by women (some of the shorter than you) on large wheeled bikes. While this may in fact be true for a few riders, it still does not mean that either they or you might not be better off on a smaller wheeled bike, such as a 650b.

[EnginCycle]

I have owned and built bikes in all three platforms. I think the majority of the issues you are describing are G2 issues. I don't personally like the geometry but I think it has a place.

I am currently ridding a 650b hardtail with a 1x10 set up and it is a good trail bike (XC). I still feel the 29R climbs better in the super technical stuff and gets over logs better. The climbing is in part from the ability to run even lower air pressure. My 650b wheels are around 20-25psi and the 29R can go as low as 15psi but I mostly ride at 18 or 20psi. That extra grip really helps and the larger foot print. EVERYONE has an opinion on this topic. Mine is based on real world experience riding all three wheel sizes. I prefer larger wheels that are attached to a bike that fits you and has good balance. Short chainstays are not an answer. Having your weight balanced and equal weight distribution within the wheelbase is much more important.

I could go on and on but IMO the bike is part of the problem not the wheelsize (part not all).

-Drew

[Liv2RideHard]

I prefer larger wheels that are attached to a bike that fits you and has good balance. Short chainstays are not an answer. Having your weight balanced and equal weight distribution within the wheelbase is much more important.

-Drew

Drew gets it. Take this advice.

Drew BTW...I really really admire your work man. One day...

Guy

[HenryA]

I agree with most of what Drew wrote, but I will add that the 650B size MTB will answer your question about slow speed handing. A properly built 650 won't feel ponderous at all.

[sevencyclist]

I faced similar question you had about the bike. I eventually went with 26" hardtail for my height of 5'7 1/2". I know the larger wheel sizes will help to go over logs and rocks as well as maintaining speed on rollers, but my primary goal is to just ride for fun, so speed is not as much of concern for me as having something that feels right. In addition, my main weakness is in having enough power for sustained climb, and if the lighter and smaller wheels help me spin up that long hill, the better it would be. I also wanted to avoid toe overlap, so 26" was just easier to achieve that.

I think I would have gone with 650B for perfect balance between 29" and 26", but I went with 26" because I was afraid of lack of choices for tires. As I understand, the 650B choices will greatly increase over the next few years, so less of a concern now than even one year ago.

I think if you go with many of the good builders to design a bike specifically for you, all wheel sizes will feel right. If you were any shorter, then at some point the standover height might become an issue with the larger wheels(29").

[Jawn P]

I have owned and built bikes in all three platforms. I think the majority of the issues you are describing are G2 issues. I don't personally like the geometry but I think it has a place.

Could you expand on this a little more? I'm considering a high zoot trek next year and am iffy on the G2. Where do you feel its place is?

[EnginCycle]

Could you expand on this a little more? I'm considering a high zoot trek next year and am iffy on the G2. Where do you feel its place is?

They allow people with little technical skill to ride over logs, get through rock gardens and essentially ride at a very slow speed and not get out of control (mostly descending). I think it is OK in open terrain but not so hot in tight singletrack. The design requires little to no rider input. If you like to ride with a little body english G2 is not for you.

[Jawn P]

Thanks for the feedback. I'm looking for a full tilt XC rig, so certainly not for me!

[Liv2RideHard]

Thanks for the feedback. I'm looking for a full tilt XC rig, so certainly not for me!

If you are considering a high end Trek...consider something handbuilt. Work with a builder and have it made to fit you. Nothing beats a machine built for your measurements and riding style/preferences. It is the way to go. Just go browse Drew's work and some of the others out there...beautiful stuff built by dudes who totally get it.

Guy

[Jawn P]

If you are considering a high end Trek...consider something handbuilt. Work with a builder and have it made to fit you. Nothing beats a machine built for your measurements and riding style/preferences. It is the way to go. Just go browse Drew's work and some of the others out there...beautiful stuff built by dudes who totally get it.

Guy

You're preachin' to the choir on handbuilt - Rody at Groovy is local and I ogle his stuff all the time!. It's a team bike for next year, so in order to sell my soul for a cheap price, the choices are Felt or Trek :banana:

[rice rocket]

Thanks for everyone's input!

I am somewhat invested into the 29er platform (well, wheels and tires only really), so being able to stay with a 29er would be advantageous there. It always puzzles me how some (well, lets say 50%) of off-the-shelf brands don't offer a 29er in small, and others will say it works great. So what is the actual limitation/tradeoff being made that some mfgs see as not worth pursuing? I've read that 29ers will never be able to get more than 120mm of travel, but that's not really limitation for XC.

[beungood]

I was in the same position as you but in looking around I didn't see too many around,Couldn't find many shops that stocked the 650B. My LBS suggested going with the 29r. Recently I saw a MTb running the LBS's handbuilt wheels and he said he had them special ordered for him.