700c crank length

I am thinking very cautiously of swapping the cranks on my 29er from 150 to 125. However, I have a couple of questions.
1 - will freemounting be more difficult?
2 - when I am on my way home from my usual ride the surface slopes gently for about 3 miles. While I am riding on this slope my right shoulder ‘leads’ and the wheel occasionally brushes my right leg. Will this get worse or better or have no effect?

Thanks in advance,

I’m currently borrowing (and soon have to return :frowning: ) a 29" wheel with 125’s. I can’t really see myself using 150s, because then it would be terribly annoying to get around!

I live in newfoundland, which is a pretty hilly place, and on occasion I need to pull up on the seat to get some more leverage out of the wheel. You should be fine with some practice though.

Freemounting will be harder also, if only because you’ve got less leverage on the wheel to get yourself going (this is of course assuming that you don’t rolling mount right now).

Your legs should brush the wheel less, I would think, since they won’t be moving around as much.

I would say go for it, my 29er is a valid method of transportation, I find myself overtaking joggers on it, which is definitely respectable when I have a relaxed amount of time to get somewhere. It’ll just take a little while to break the cranks in until your brain gets used to them.

good luck!

125s should be no problem. You might even find that they make freemounting a little easier as the wheel is less twitchy. (I use a static mount with just a slight push on the uni which makes the back pedal rise slightly to form a step.)

I bought my 28 with 110s and was able to idle it on a smooth surface straight away. I now ride mixed terrain on 102s, and only have problems on steep hills. Obviously, preference and experience come into it, but I’m sure that you will not regret swapping your 150s for 125s.

You get to raise the seat an inch too, which make the unicycle more elegant. :sunglasses:

I’ve used both 125’s and 150’s on my 29-er, and posted several threads comparing them- a relevant one is here-


IMO there are several factors involved,possibly the most relevant being how regular you’re riding- for me, using 125’s needs regular riding to give reasonable control for riding in places where there are pedestrians or cars, whereas 150’s give sufficient control for if you have periods of not riding.

I also suspect that leg length is a factor, with shorter riders doing better with shorter cranks and taller ones doing better with 150’s.

It’s harder to do rollback mounts with shorter cranks but not much harder to do static mounts. Rollback mounts are perfectly possible on 125s.

It’ll feel weird for a couple of hours because your legs are only going round in little circles, but you’ll get used to it.

I don’t think it makes much difference to the squirlyness on angled surfaces. I found that a combination of having a slightly higher pressure in the tyre and getting used to riding on angled surfaces helps combat that and I don’t get that any more.


Thanks for that.
I may try the 125s, I can always swap them back. The LBS probably thinks I’m bonkers anyway. (they didn’t stock any front lights that would fit on my seatpost)


PS onewheeldave, do you spin anything else?

Yes, poi, meteors and various juggly type things; why do you ask?

I ride a 29er with 102s. It’s just a tiny bit tricky to mount.

I always say that you have to mount it like you mean it. Always assume you’re going to make it – full of confidence and sans all doubt – and you always will!

on my 28 i have 89’s and its acually kinda tricky to freemount… i have like 9/10 ratio… i miss everyonce in a while, idling is no where in sight… but i just cant get enough of the speed. i fell like with 125s id feel to slow… buts id be able to idle and stuff…


Don’t know really, I just had a feeling, maybe I’ve ‘seen’ you on another forum - Home of Poi or Fire Toys or something, or on a video. Fire definately springs to mind in relation to it.
What d’you think?
(PS I spin too - poi, swinging clubs, fire, staff etc)


oops, I think i’ve thread jacked myself.

Wow, riding with 109’s and 85’s and things. I feel like a right woos, being cautious about 125’s. Hang on though, I am a right woos. so that’s ok then.


(PS I don’t know how to spell woos, but I mean wimp, woos just seems to describe me better. Sorry)


It’s Wus, at least here in the great white north! And your not a Wus!! No one who masters a uni can be considered to be a wus!

I think you will be very pleased with 125’s. Like any change in your uni set up, you will need time to get used to them, but not much!

I use 125’s and find the rollback mount very comfortable. It just takes a bit higher of a hop is all. And I think it is easier to idle with the shorter cranks (and you don’t feel like your knees are going to kick yourself in the chest)!

Steep hills take a bit of getting used to. Not going up, but going downhill. The momentum of the 29 inch wheel takes a bit more to control, but you get used to it very quickly!

Give it a bit of time and 125’s will feel very natural.

I use 125’s on all my uni’s except my 20" freestyle on which I use 110"s.


Errrm, I think it may be Wuss here in the great grey middle.

Go for the 125s Cath. It isn’t any more difficult to mount, just different, so your brain and legs will need time to adjust. If you do a running mount, because you have less leverage on the cranks, the momentum in the wheel has more effect in “lifting” you up to seat height. The bigger and heavier the wheel, the more this effect will work to your advantage. If you rollback mount then you will initially find it more difficult to control the speed and distance of the rollback bit.

Because your riding will become smoother with shorter cranks, you may find that you are less likely to have problems with leg-strike on an adverse road camber. More speed will help too :wink:



Smoother is great.
Bigger hop on rollback mount is manageable.
Ok, soon as I come back from my hols, I’m changing the cranks.
Thanks for your imput folks.

Probably HOP, i post there a lot- I’ve also put several vids up on the net, some of which involved fire,so it could have been those.

I believe some one on this board was working on poi spinning whilst unicycling (one of the joes I think) and got to the stage of behind-back-weave while on one wheel.

Now there’s an idea.
My fav spinny thing is swinging clubs.
I wonder if it would be easier than juggling on a uni?


Doing a normal weave with poi on a uni while riding along is easy, probably a bit easier than juggling 3 balls. Doing it while idling is a bit weird, you have to be able to do poi with your arms more than your body if you see what I mean.

Most poi things I can do on flat ground I can do on a uni. There’s a few moves where the wheel gets in the way and doing behind the back weave while idling I haven’t got down. I can only do that while riding along.

It’s just occured to me that doing a leg wrap on a unicycle would be cool. You could do it out of one foot idling. I also kind of wondered about doing wraps around the seat tube, but I’m not sure if I can do that in a way that won’t burn my legs off.

I’ve attempted to swing clubs on a uni, but I’m rubbish at club swinging. It was not really much harder than doing them on the ground, but I don’t know any clever moves with clubs.


ok, LBS have swapped my cranks today.
I haven’t had much time to practice due to ‘life’ getting in the way. However, early indications are good. It doesn’t feel that different to ride but slightly more agile. Slightly more difficult to feemount, but I managed twice.
Hopefully I will have a bit of time to get used to them before the winter closes in.
Thanks everyone.

Cathwood, I like reading your posts because your enjoyment of riding shines through what you write.

You will have no difficulty getting used to the 125s. All it takes is self belief and a bit of practice. Just ride that sea front and enjoy the experience. In a year’s time, you will wonder why you had doubts.


Thanks Mikefule.
But self belief, that’s sooooo hard.