older KH trials cranks stripped! need help!

I have had my KH trials unicycle for a number of years and have wound up with stripped cranks. When looking around trying to find new cranks all I could find were the new ISIS ones, and from what I have read I am unable to use these on an older model. Is there any hope or am I really going to have to buy a whole new unicycle because of a pair of stripped cranks?!?! This is really putting a damper on my riding time! Thanks for the help!

Phil B.

Any ideas?

Have you taken them to a LBS and get them retapped

If i remember right, you can just turn the whole crank around… the thread should go all way through and you can insert the pedal on the other side.

Mine have got a bit of Q factor so you can’t trurn them.

Might be worth a phone call to UDC they might have some in box somewhere even if they aren’t on the website. You could try a wanted ad, someone might have some spares (I do, but I’ve got 2 KH splined hubbed unis so I’m holding on to them :slight_smile: ). Even if you find some it might be cheaper to buy a new ISIS hub and rebuild the wheel.

I think Darren Bedford still has some of the old-style in stock.

I see that he has some. What type would I need or would work? ONZA, Moment, Sym?

If your hub is not ISIS it’s probably Onza (36-spline). If so, it probably says Onza or KH/Onza on it.

Or is it old enough to still have the 8 spline cranks & arms?

Other alternative: You can have a bike shop drill out the pedal hole, and they can re-tap it and stick a new insert in.


I would suggest looking for a new pair of cranks. Getting a pair of unicycle cranks tapped isnt such a good idea. The inserts are pretty soft and for bikes they work just fine as long as you are doing “easy” riding. I had a pair of cranks re-threaded and broke them the next day.

I can also imagine that the cost of the repair would only be slightly less than a pair of cranks.


If these are CrMo cranks you may be able to have the threads rebuilt with welding rod, re-drilling and tapping.

A more gentle repair could be some hard silver solder over the threads in the crank, and just to retap without the drilling. If you pair this up with a new pair of pedals with longer threads you may be into a workable fix. The threads on the steel cranks are pretty deep, so if it’s tapped from the back side the new threads will align perfectly with the old ones, and hopefully the new pedals will be in the original threads a bit.

That’s not true; the place that did it for you probably did it wrong! The inserts should be just as strong (or nearly so).

Actually, if you look at the KH alumn cranks, they all have inserts standard.


I am with Tholub…you probably want the Onza cranks. I have two unicycles (24 and 29) from that era and a set of pedal cranks in each size (125, 140, 150, and 165) to allow me the greatest flexibility. I like that generation because of the significant Q factor. If you like the way your unicycle operates now, it is worth the effort to find a set. They are around, I bought my 140s a couple of years ago after looking around a bit.

The place that threaded my cranks make there penny fartherings 100% from raw materilas. Pretty sure the guy did it right.

Also in KH cranks they have an entire two piece chromoly insert. Unless you have a bike shop that has these i highly doubt that is what you will get. Yes the KH thread inserts are the best there is. They also pretty expensive.

If you did take the cranks to a bike this is prolly what they will repair your cranks with


I have also re-threaded a pair of cranks for my friend. I can tell you from first hand experience that these things really arent that strong.

I have some pictures to see if this helps. I am not sure what the different cranks are or look like. I know these are 140 but thats about it. I took them off and flipped it around to see if that works and the pedals do not want to go in easy still. Its not the pedals because I took them right off my KH 26 inch muni (same model year as this). The pedals go in easy and straight on the muni but not on the trials even after I flipped it. I have no problem buying new cranks I just want to make sure they are the right kind. Thanks again for all the help and advice!



Oh, yes, those are the very old 8-splined ones. I’m not sure you’ll find any of those anywhere.

You could get a new hub and cranks and rebuild the wheel. I realize it would be a lot more work than just switching out cranks.

Are the bearings 42 mm diameter with a 100 mm spread? If so, any of the modern hubs would work.


The bearings are almost certainly 40mm, which means that you probably can’t find a hub in stock that’s trials-appropriate that will fit the frame.

You could get an ISIS hub and the 22x40mm bearings:

They don’t actually work very well but they’re probably OK for trials.


Okay… Well… Turns out who ever assembled my unicycle 9 years ago put the cranks on the wrong side! I have no idea how I never noticed this but I just flipped the cranks around put them on the right side and now they are working fine. Thanks for all the help everyone! You have now made me realize just how old and out of date my trials unicycle actually is ha.