Author Topic: another questionable rim: rideable or not?  (Read 319 times)

another questionable rim: rideable or not?
« on: January 27, 2019, 02:22:41 pm »
This happened when I was riding along a dark cycle path one evening. Commuter with Strobe light was coming the other way so I couldn't see a thing, and ended up doing my rim into some cracks in the asphalt. The rim has a series of scratches from the side of the crevice I fell into and out is noticeable when I brake.

Ride it or replace?

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Re: another questionable rim: rideable or not?
« Reply #1 on: January 27, 2019, 03:10:16 pm »
ooh that's both unfortunate and nasty.  The shallower  scratches should largely buff out with a bit of wet and dry but there are more significant deformations that are probably causing the brake to be 'pulsy'; the brake blocks are certainly not making uniform contact with the rim any more.

Some gross deformations of the rim can be manipulated but smaller dents are very tricky -or impossible-  to get rid of.  If this is a front rim then if you have to brake at the resonant speed (when the forks are twanging back and forth in unison with the wheel speed) then this puts unusually high fatigue loadings into the fork and frame. If it is a rear wheel it is probably less of a worry.

I think you would be unlucky to have the rim itself fail (unless some of those scratches are actually cracks) but what the pulsing will do and what any reduction in brake power  may do are probably of greater concern.

cheers

Re: another questionable rim: rideable or not?
« Reply #2 on: January 28, 2019, 08:47:11 am »
Thanks - interesting.
I rode 100km on it on the night.  I knew something was wrong with the wheel from the braking but thought it was a spoke, but I checked them and they all felt ok.  When I saw it in the daylight the next day, I decided I didn't want to ride on it again and swapped the wheel out.  I was concerned about the rim becoming fragile as well as impared braking.  It looks like that was the right decision: I'll get a new rim.