Bent Rear Disc

Anyone ever repair a rear bent disc?



I crashe very bad in the rocks/trees last Sunday.(Cinco de Mayo...again!DAMNIT)

I had the front wheel kick up from one of thos sharp edged lunkers in a corner and the rear clipped it and sent the whole bike sideways in the air with me onboard. I did not even have time to put my foot down and landed in the rocks with the bike on top of me.

My Acerbis hand gaurd save the front brake lever but it seems the rr disc took a blow too. just noticed it is slighly tweeked.

Any suggestions?

Find a shop in your area that straightens street bike frames. They should be able to true your rotor. Might even do it while you wait. My buddy had two rotors straightened for about $30 on his street bike.


Hey Hucker,

Have some machinest skills from days past this is what I would do.

First check what the run out is "How far out of whack it really is" If it is under about .100 I think you could get it turned at a local machine shop or auto parts store that turns brake discs flywheels.

The .100 is just a guess don't know how much you can shave off of the disc and still have the range on the caliper piston.

P.S are you going to D land? I will still be looking for you if you come down to jericho.

Take er easy

Call Rocky Mountain MC. IF you need a new rotor, you can get a Titax unit for like 49 bucks. I had a bent rotor and the run out was only like .075, not a bunch, but that son of a hooligan would completey open the slave cylinder on one panic rev. There is nothing worse than having to pump up the rear brake on an entry. I wish I would have had the Rock Catalog then, it would have saved me a bunch.

Hey TRH, I have a bent rear rotor as well, I have the subframe and shock off right now and I just leaned directly over the top of the rotor and kept spinning the rear wheel until it hit the spot w/the bend. Put a crescent wrench on the rotor, pulled and tweaked until the rotor was close enough(straight) to allow the wheel to spin freely again. I'm sure a machinist shop or the purchase of a new rotor is in order but mine was stopping the rear wheel like the brakes were being applied, not it the Redneck way, but it worked for me. Good luck. Jason

I did what JasonKC did until I finally gave up and bought the new rotor.

Hey Thump, let us know how you solve this problem. I'd like to know if you find a shop that staighten's it for future reference.


Buy a new one or look for one on Ebay. I have seen them out there quite reasonably priced. I would not mess with it.

I bent the rotor on my '98 and tried the crescent wrench trick. No luck. I made an AutoCAD drawing of the thing (extremely accurate, like with dial micrometers and stuff) and had a local laser shop burn me one. Twenty bucks, I countersunk the holes and was good to go. I used A514 steel. May have been a little soft. It lasted for a long time and was still good when I got rid of the bike. Good luck.

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