Finding Crank parts -koxx reinforced

So a friend gave me a unicycle, and It’s all together, but it has 140mm KOXX reinforced cranks.

At the end of the cranks, where the pedal threads into the arm, there is a threaded adapter of sorts. On one side it is there, but on the other side it is missing. (I’ve attached a picture of the cranks as they should be)

the piece looks like it goes from a 1" down to the 1/2", and can be removed with a pin spanner.

I’ve been looking around for a replacement part, or even what the name of this part is called.

Can anyone help?


Follow my tutorial, the ring isn’t necessary anymore once you’ve done that. I have done it on several cranks, I’ve had 2 inserts to come out again at the moment, about 4 years after the repairs.


I don’t have the tools or technical expertise to do the thing in the video. Is there anywhere that I might find these parts? They’re called crank inserts, I think?

The thing you are looking for is called a crank insert, and it is almost impossible to find as a spare. It sucks, but you’ll probably be best of just buying a new set of cranks.

If you already lost the ring at the back, all you need is a pedal wrench. Have you ever put glue on something? It’s basicaly the same thing, except the glue is stronger.

Koxx one died years ago, and I’m not sure if they used the same inserts as KH or not. It’s easier than expected. The parts will be very hard to find, and to install it, you’ll need to have a pedal wrench and a Pin Spanner.