Trials Crank Arms: Impact "Eiffel Tower"

Been thinking about getting longer crank arms for my trials uni; currently running 125’s. I have read a lot on here about how trials crank arms usually range from 137 - 150 and was wondering which length people suggest. I was leaning more towards 140’s but was wondering if I wanted to do some street/flatland tricks could/would I be able to do that stuff on this uni with longer crank arms?

From what I’ve seen on here I should be able to do street and flat land on a trials uni…how far off am I on this one?


You can definitely do street and flatland on a trials unicycle. I rode flatland on a Nimbus Trials Unicycle with 137mm cranks for quite a while and it was totally fine. That being said you can also ride trials with 125mm cranks. It really depends on which style you plan to ride more.

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People tend to preffer shorter cranks for street and flat and longer for trials.

I’ve seen people to both on 150’s and someone get enough speed to jump a 12 set w/ 145’s.

150’s…man that’s pretty long. So another question I had was, will I notice much of a difference if it got a pair of KH 137’s instead of my current 125’s? If so, is there really that big of a difference between 137’s and 140’s?

You should easily notice a difference between 125’s and 137’s. The difference between 137’s and 140’s is much smaller and probably won’t be noticeable.

WEEEELL then, guess I’m gonna have to go with the KH 137 moments. Are the Rollo Disks worth the money?

How much Q-factor a cranks has can make more of a difference than length. More = better control at slow to moderate speeds but more wobble at high speeds.

I don’t know if this is true or not but that wobble may affect riding really thin skinnies like a 2" round pipe. I can’t ride anything I’d consider skinny but for my riding I like lots of Q, I’ve never ridden a crank that I felt had too much.

Ventures have virtually no Q, Moments a bit more. Qu-Ax 10 sline cranks have a lot more Q (more than any other crank I’ve tried), so I would guess their ISIS cranks are similar, but I’d ask UDC.UK about those and the Eiffel Towers. The older KH-Onza cranks have more Q than the Moments, I think it’s less than the Qu-Ax 10 spline, but I’m not sure.