I just switched my 125mm down to 102mm for the idea of more speed-
I haven’t had a chance to test them out yet but will be going out tomorrow for a good run!
Are the cranks to short for the 29? Will they have enough torque? Just don’t want to go and break something if it is unnecessary.
Thanks
Whether they’ve got enough torque depends on your level of skill and how steep the terrain you’re riding.
If you’re comfortable on your 29er and you’re riding on reasonably level ground with a decent quality surface then you should definitely find that the torque level is reasonable. You should still be careful though, because changing crank lengths can cause you to UPD more (and in interesting ways) - at 29er speeds, this is worth bearing in mind.
If you were doing offroad or lots of really steep stuff, you probably wouldn’t want to go that short (again, depending on personal preference).
I rode my 29er with 90mm cranks for a short while but found it uncomfortable to have cranks that short, although it did give me better sprinting speeds. I’m currently on 127mm cranks, which I find are good for going moderately fast on road or off.
I dont think it will be that bad, if you just use it for riding places it will allow you to cruise at a higher speed, which will be good. I have 125’s on mine now, and i like them, but I have ordered in some 114ml’s and will post up how they feel when i get them.
I crashed with 102s on a 27 (slightly taller than 700C) last year but I was relatively inexperienced and really pushing myself.
If you have ridden 127s for a long time it shouldn’t be to big of a switch.
I am thinking that I am going to give 114s a try on my 36er now that I have ridden quite a bit more but I am not sure if I would ever go back down to 102.
125s to 102s is a pretty big jump, but I wouldn’t hesitate trying 102s on a 29er. Just take it easy at first.
You should definitely try the 114s, maybe shorter. The 36er hadn’t really come alive for me until recently when I switched to 110s from 127s.
I probably will end up going down to 102s on my 36 but probably not for a while. 127 do feel sort of long sometimes if on a 60km+ ride.
When I put the 102s on my road skinny I was barely comfortable with 127s.
I also had lead weights on my wheel but that is a different story 
102s should be fine for an experienced 29er rider.
Are all of you using riding on pavement or off road with these crank sizes? Sounds a little short to me for off road. I’m riding with 152s on my 29" and use it equally off road and on.
I was wondering if off road I could get more leverage on the up hill with longer cranks but didn’t to switch yet until I get an alternate uni probably a Coker.
Yeah Ive been considering going for 4" cranks on my 29er but im not going to right now…Tell me how they feel compared to 5".
Hey and were you at OUI 07? You won the BC WHeel? Bought a KH20?
I was the only small kid in the sport categorie…
Isaac
I think the results may depend substantially on your choice of tyre (and yes, intended usage!)…
Last year I was doing a lot of road riding on a 29er with a 2.35" Big Apple tyre. I started with 127s, changed to 114s and found this a big improvement - essentially no loss in control, but easier to spin, only downside was it wasn’t quite as good off-road, but probably better overall / as an all-rounder. I then had to change to 102s (I bent a 114 in a silly accident involving catching the QR handle of the seatpost clamp in my shorts…!!!), and…well, possibly better as a long-distance (40mpd) road machine, indeed I hit some fairly decent speeds, but substantially harder to control, couldn’t idle (had to hop at traffic lights), and couldn’t handle anything more than verylight* off-road, preferably gently downhill.
This year, tho, after a long time riding a 26, I’m using a Nimbus 29er XC with 29*1.95 Kenda Klaw tyre. This weighs approx 700g to the Big Apple’s 950-1000g, and with 102s again, the difference is enormous. I guess it probably doesn’t hold it’s speed quite as well in some situations, but on the whole it’s enormously better: much more manageable/controllable, much more manoeuverable, can get up to speed much more quickly (i.e. acceleration/deceleration), idling not a problem, surprisingly capable off-road (nothing very heavy, but canal towpaths, mud, many poorly-surfaced “bike paths”, trials, etc. etc.). I suspect that whereas 114s seemed “the right length” for the Big Apple, 102s are “the right length” [for me] for the Klaw as an all-rounder, and as such it’s a much better uni; however, the effect of the change in tyre is such that I’m even tempted to try 90mm cranks - for more speed on-road, even if I doubt that’ll be as good all-round…
Alan
I just switched my tire as well to the Kendra Klaw-so it looks like I am in the same scenario as you-
I will be doing mostly road riding-maybe a little off road, but nothing crazy at all!
Thanks for all the info
102s are the best! i have them on my 29 and it just powns
No-I couldnt make it out to OUI But wish I could have though!
But I must know you-as we do go to the same unicycle club 
lol
I ride a KH 20-I have been going out to the club on thursdays mostly-but after the Christmas break I will be going out monday and thursdays