Bent Rotor

**Ski Monkey** · 09-03-2004, 12:56 AM

JONG alert...

So, somehow my rotor got bent. No clue how, perhaps in transport, maybe it was the rock that dented my rim. Anyhow, what's a good way to straighten it out? When are you better off just buying a new rotor?

**snow_slider** · 09-03-2004, 06:15 AM

Depends on HOW bent it is.

If mine is tweaked, I just use two adjustable wrenches to work it back straight. Clamp the wrenches down on the rotor and GENTLY tug at them to straighten it out.

If your rotor is badly bent, then you will most likely need a new one. Definitely try to straighten it with a wrench first though.

**Mr. Altagirl** · 09-03-2004, 07:49 AM

I use a crescent wrench as well. Just go slow like truing a wheel and you should be able to get it straight again.

CS · 09-03-2004, 10:12 AM

Yeah, couple of crescent wrenches should work. You might want to warm it up with a torch to make it easier to bend. Be careful though.

**phUnk** · 09-03-2004, 11:39 AM

Originally posted by CS
Yeah, couple of crescent wrenches should work. You might want to warm it up with a torch to make it easier to bend. Be careful though.

MAKE SURE to put a rag over the rotor so the metal of the wrench doesn't touch the metal of the rotor directly. That keeps grease from the wrench from gooping up the rotor & then your pads.

I've straightened 3 rotors and never used a torch. They're only 2mm thick and it's kind of delicate work, so you don't really need to soften up the rotor to tweak it out. Plus, I wouldn't be stoked about pointing a torch at my spokes or hub, etc. (Summary: I heard that CS guy sucks, so don't listen to him.

)

**lph** · 09-03-2004, 11:40 AM

i have bent 3 this year and i am going to start carrying a spare.

anyways besides gently using crescent wrenches, can you guys give a little more details? i mean where do you grab the rotor, do you grab it near its center at the base of the arms? do you grab the actual braking surface? how do you tell when you have straight, by putting it back on the bike?

i have brought it in and had it done at the shop and they do a tremendous job, but it costs, i would like to start doing it on my own.

**lph** · 09-03-2004, 11:41 AM

so, phunk, you leave the rotor on the bike while you are working on it?

and yeah, i have ridden with CS, take everything he says with a grain of salt.

**phUnk** · 09-03-2004, 12:54 PM

Bent 3 rotors? Carry a spare rotor? In what, a titanium carrying case? Holy crap, those shop guys must love your jong ass!

Leave the rotor/brakes/your-pants on.

Rotate the wheel slowly and look through the brake caliper to see if the rotor rubs the left or the right side of the brake pad.

Rotate until you hear the "SHING!" that signals a bent spot scraping a brake pad.

Rotate the wheel back and forth in small increments, zeroing in on the center of the SHING. This is the most warped section of the rotor.

Rotate the wheel until that spot is accessible by wrench.

Put a clean rag or paper towel over the braking surface of the rotor.

Clamp an adjustable wrench over the paper towel braking surface of the rotor.

Using the wrench, push or pull the rotor in the direction you want it bent.

Work incrementally, checking your progress against the brake pads after each successive bend.

The SHING should get quieter/shorter after each iteration, until it goes away.

Now repeat this process for any other spots on that rotor that rub. You can use a sharpie marker to mark the spots that rub, or just use any markings/stickers on the rim as a reference.

If you bend/warp a rotor while riding, you can do this same procedure using just your hands and something clean to protect the rotor from your grimy hands/gloves. Get any grease/oil on that rotor and you'll probably finish the ride dragging your feet, Fred Flintstone style.

**jayfrizzo** · 09-03-2004, 01:04 PM

Originally posted by phUnk
Blah blah blah tedium blah.

Fuck that shit. Just bang the fuck out of it. Then drink a beer.

**phUnk** · 09-03-2004, 02:21 PM

Originally posted by jayfrizzo
Fuck that shit. Just bang the fuck out of it. Then drink a beer.

Said the guy who has to adjust his brakes every 30 minutes of riding. Bwa!

**homerjay** · 09-03-2004, 03:38 PM

I haven't found the rag/towel necessary, but everything else phunky said is right on the money.

**lph** · 09-03-2004, 05:43 PM

cool, thanks phunk.

i ride hard and ugly and tend to go out of my way to hit the most rocks i can in any one ride. tends to make for alot of bent rotors.

(and most recently a blown 5th element shock

)