Loose crank

Alas, one of the cranks on my 20" Miyata started to get a little loose.
Unfortunately, trying to tighten the nut that draws the crank tighter onto the
axle doesn’t work - it appears to be stripped (I know it is the axle and not the
nut, because I tried another nut and it still doesn’t tighten). I devised a
temporary solution by putting a washer under the nut - that moved the tensioned
area a little closer toward the end of the axle, apparently to a place where the
threads are better, and it seemed to tighten up.

Has anyone had this problem?

Is there a good/permanent solution?

Scott

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Jody, Vjera, Luke, Hope, Thad, and Simon Arnold: The local unicycling family in
Springfield, Oregon.
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RE: Loose crank

> doesn’t tighten). I devised a temporary solution by putting a washer under the
> nut - that moved the tensioned area a little closer toward the end of the
> axle, apparently to a place where the threads are better, and it seemed to
> tighten up.
>
> Is there a good/permanent solution?

It sounds like you are nearing the useful lifespan of this axle. Hopefully it is
not a new one. If being used for light riding, it might go a long time if you
loc-tite the crank and nut, but that would mean removing the crank again. There
is some wear and tear incurred every time the crank arm is removed, which
eventually leads to them wearing out. Especially if you’re using non-steel
cranks, and especially also if the unicycle is being used for any high-torque
riding, like MUni.

Fortunately new Miyata axles are very cheap. Unfortunately, rebuilding wheels is
a big pain…

Stay on top, John Foss, the Uni-Cyclone http://www.unicycling.com

“The hotel was great. You couldn’t trash the place.” - Andy Cotter, praising
the UNICON X Jing Yan hotel, which let us ride in the lobby and pretty much do
as we pleased.

Re: Loose crank

I think i may be able to help in this matter. I have spent many years as a cycle
mechanic, and have come across your problem many times. When a crank becomes
loose, the wobble on the axle. As cranks more often than not tend to be made
from aluminium, and axles are mad from a hardend steel, the crank wears and what
should be a nice square pattern in the end of a crank becomes rounded. Once a
crank has come loose, IT MUST BE TIGHTENED IMMEDIATELY!!!. otherwise irreprable
wear occurs, and the solution is a new crank.

I would imagine this is the problem in your case. It is certainly the first port
of call, and considrably cheaper than a new axle and wheel build…

Hope this helps

E.R.