Loose Crank...But Not

My KH26 feels like the left crank is loose. When I sit on the unicycle and rock back and forth, the crank on the left feels loose when the left foot is forward. When I put the right crank/pedal forward, it feels nice and tight. I have taken off the cranks and rotated them, checked the tightness of pedals, and tightened every bolt I can think of. How can I tell if it’s a problem in the hub or a bearing? I don’t want to buy a hub and invest in a wheel build unless I know that really is the problem. Any advice?

You can check if it’s a bearing fairly easily; just take off the frame and see if there’s any play in the bearing itself, or of the bearing on the axle.

The problem could easily be in your seat or seat post; thunks transfer through unicycle frames fairly well so you can’t always tell where it’s coming from.

That’s true. I tightened all seat bolts as well. I just find it weird that it only happens on one side. I’ll check the bearing when I get home.


I guess it’s not that :slight_smile:

What are the cranks you’re using? Maybe if they’re aluminum without steel inserts they’re worn out so they can’t be tightened anymore. That happened to my Nimbus Ventures.
Also it could be that the pedal bearings are shot. Happens a lot to me. Then they feel strange and have more play than usual.

It seems highly improbable that the hub would exhibit a problem on just one side.

How old are the pedals? They may be tight to the cranks, but have a bad bearing in the pedal itself. If you hold the crank with one hand and the pedal with the other, does the pedal wiggle on its axle?

It may be the bearing of the pedal thats broken.

The cranks are KH Moment. The little insert ring thing for the pedals are nice and snug. I’ll trade my pedals and see if that fixes the problem. I have the Animal Pedals. They are fairly new, but could be flawed. I’ll check it out tonight. Thanks for the suggestions.

Spin the seat in the frame and try riding it “backwards”, see if the problem remains but now is present on the opposite side.

Next try installing the “bad” crank without a spacer and see if it tightens up.

Once I had a definite “loose crank” on one side. I immediately jumped off the uni to check if the crank was tight. I didn’t find anything wrong, and sure enough the looseness was gone when I got back on.

Some time later, the same thing. I started to get a bit paranoid as it was a long walk back to the car.

Turns out it was my shoe tread. A piece of tread would rake itself one way over a pedal pin during a part of my revolution, then pop itself loose from the pin in another portion of my rotation. The result was a loose popping feeling with every rotation at the same point in my rotation.

Stranger things…

I never would have thought of that.

Something to keep in mind next time I get another “loose crank”.