Correcting a deformed rim

paulbnix

A friend had an incident that resulted in his front wheel having a wobble of about 2cm. He managed to cycle home with the brake caliper released.
I had a play with the wheel to see if I could straighten it. I managed to reduce the wobble to about 2mm but the difference in spoke tensions was too much.
The wheel should have about 80-90 kgf - they actually varied from 150 down to 50.
Is there anything else that could be done to rescue the rim?

bbrap

I'm no expert but if it requires that much tension difference I would suggest the rim has been pushed past the point of elastic deformation and is not suitable for repair. You may be able to straighten it with a bit of brute force on the rim but I doubt it will be able to retain a circular shape for long once being ridden.

cycleclinic

If you cannot even the tensions out and keep the wheel straight then the rkm is bent. 2cm though is not alot. When building a new wheel i get all the nipples to the end of the threads. Typically there is 1 to 2cm of wobble in the wheel. The rim is not permentaly deformed. By evening out tensions the resulting wheel is round and straight to 0.2mm. I therefore think tensions can be evened out this requires a truing jig though. It is hard to do this with the wheel in the fork.

Given younhave a tension guage you may have a jig and you may know how to even out tensions and keep the wheel straight in case it is bent.

The Rookie

I'd slacken them all off and start truing from fresh, while 2cm can be a buckled rim (depending on the nature of the distortion) it wouldn't normally be.

paulbnix

I have decided the rim is toast.
I first evened all the tensions then tried to take the buckle out which is how I ended up with 150 and 50 on adjacent spokes.
After I removed the rim it won't lie flat.

ugo.santalucia

yep, it's one for the local recycling centre. If you have a metal dealer and the rim has no eyelets, you might get 20 pence for it