Does anyone know of a 125-135mm ISIS bike crank?

Sup homies, im building up a uni and i am trying to find the lightest stuff i can for it, uni cranks are tanks when it comes to weight, does anyone know of a crank that is either 125mm or 135mm or anywhere inbetween? Bike cranks tend to be very light compared to uni cranks.


Maybe the koxx-one ISIS light, it comes in 140. I don’t think bike cranks are all that short generally. Anyway, what are you making?

A unicycle.


I’ve heard of cranks being cut and welded with re-enforcment. I think it was done with 145 profiles and made to 125. Probably considerably weakened the cranks though. I never heard how well they held up. I’ll search around and come back if I see something.

Problem is most isis cranks are solid aluminum.

wouldn’t a suzue hub with some light track bike cranks be far lighter than any splined setup you could get for a uni? does it need to be super strong?

After a bunch of searching, this is all I came up with:

Too bad they won’t work for you. Sorry.

Yeah, Forgot to mention that was the one company i found. They are race bmx cranks however. I emailed the company and they said give it a shot because they are cheap, but they dont know how strong they are.

They might not be strong enough. What is the uni gonna be used for. Street I presume.

Trials mostly, some messing around with flatland and tricks.

The Sinz will more than likely not be that strong. They are “mini” bmx cranks…meaning they are designed to be used by young kids that are light, and don’t jump much. “Mini” stuff is usually designed to be as light as humanly possible…sub 10 Lb bikes are not unheard off…and durability is not a big concern. The one thing that would be a major problem is that built in spider for the chainwheel/sprocket…that would need to be ground off…hassle. Aren’t there some small QU-AX cranks on Germany)?

Come to think of it…PDC on the board knows someone that can machine extra threads into Kookas for adjustable lengths…I don’t see why they couldn’t take any aluminum crank(including isis), cut them off, and machine the threads at the length you want. I’m sure it wouldn’t be cheap…but it might be worth an IM to PDC.
If you’re willing to go that far you might just want to get a brand new Kris Holm Moment set-up in 125mm.

Good luck man…wish you luck.

Iv been podering trying the Sinz cranks, I can remove the spider with a mill. Im just worryed about snaping a crank off or bending it, However they are only 50 bucks. Lets raise the bar, Anyone know of a isis bike crank thats between 150-140?

140mm but I think lighter than KH.

Wow, Those are insanley light, lighter than the Sinz which are skinny race cranks. Does anyone know if these will hold up?

I told Marco to get Onza Tensile cranks because he was looking for the lightest uni available, but he was advised not to buy it because it hasn’t really been tested by anyone yet. So I don’t think anyone on the forum has any experience on this item.

And about short ISIS cranks, Qu-Ax has some but i don’t know how strong they are (they’re very short so I think they’re strong enough):


They are also some of the lightest cranks out there.

The second pair have a pretty strong design.

I wouldn’t worry too much about bending them…

It took a five foot drop to really do any big damage to Dumpweeds cotterless cranks, the really thin ones that come on lots of cheap unicycles.

I was talking with Sponge and Joe, and they said that those Onza Tensile cranks will be the same strength of the KH moments. They sound good to me. =p

Those quax cranks are horribly light, Anyone know if they are strong?