Crankshaft problem-need some help

OK, so I recently bought an avenir 20 inch mountain unicycle, my second unicycle, and I have been riding it and noticed a slight wobble in the right pedal, I grabbed a pedal from a bicycle and put it on, to see whether the wobbliness was in the pedal or the crankshaft, the problem persists.

So, I was going to take it apart, but on the avenir, the bolt on the crank shaft is sunk down and I cannot put a wrench in there, I am planning to ride this unicycle in a parade on Tuesday, and I am afraid that the wobbliness is stripping the thread on the shaft, as this is what happened to my last unicyle, although it was a generic chinese version.

so any suggestions or warnings or advice would be appreciated.


If I understand your problem your crank is loose. You should tighten the crank bolt/nut asap, and really not ride it until it is secure. Riding it loose will round out the flats on the crank, and that will ensure that it will never tighten correctly.

You need a 14mm socket wrench for a standard bolt/nut, or an 8mm Allen wrench if it’s a hex socket type bolt.

Don’t ride it until you get it tightened up; that will just make it worse, and possibly not tighten-able in the future. If you don’t have the appropriate tool, a bike shop may do it for you for free. Ask for 40 foot-pounds of torque. You could also buy a crank wrench, something every unicyclist with square taper cranks should have. Or stick with the 14mm socket, which is a little more useful for other stuff…