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Author Topic: Warped/Bent Brake Rotor  (Read 2267 times)

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Offline RKL

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Warped/Bent Brake Rotor
« on: September 29, 2008, 07:57:22 PM »
I ride a Gary Fisher with Avid hydraulic brakes.  I've apparently warped or bent the rear brake rotor.  The tire spins true - but a bend/warp in the rotor stops the wheel from spinning after a couple of rotations when spun pretty hard by hand.  Spinning the wheel slowly by hand - it looks like the bend or warp involves about a quarter to third of the circumference of the rotor.  Any chance my LBS might be able to do something to trim up the rotor or am I SOL & buying a new one??

On a separate issue, as a newer bike owner I'd like to become more familiar with the mechanics and maintenance of the bike.  Of some of the moutain bike maintenance/repair books that are out there, does anybody have a recommendation of one that might be good for somebody without a lot of mechanical experience?

Offline BillT

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Re: Warped/Bent Brake Rotor
« Reply #1 on: September 29, 2008, 08:14:57 PM »
You can try to true the rotor yourself by clamping down on the bent part with an adjustable crescent wrench and trying to bend it back straight.  Your LBS may also have a tool for getting them straight as well.  Worse comes worse, you buy a new rotor.
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Offline Jim DeLuca

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Re: Warped/Bent Brake Rotor
« Reply #2 on: September 29, 2008, 08:17:25 PM »
The lbs should be able to straighten it for you depending on how bad it is.  You can do it yourself, but I won't go there, as I have not seen how bad it is.  As far as basic maintenance goes, AJ's gave a clinic this year I believe, and from what I heard was very helpful.  Maybe we can get someone from the club to put on one.  

Offline BeerCan

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Re: Warped/Bent Brake Rotor
« Reply #3 on: September 29, 2008, 08:34:40 PM »
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Anthem1

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Re: Warped/Bent Brake Rotor
« Reply #4 on: September 29, 2008, 08:59:28 PM »
Park tools web site offers some great how to's :)

Offline slowfatguy

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Re: Warped/Bent Brake Rotor
« Reply #5 on: September 29, 2008, 10:46:56 PM »
just make sure there isn't any oil or grease on the tool you are using to straighten the rotor.
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Offline RKL

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Re: Warped/Bent Brake Rotor
« Reply #6 on: September 30, 2008, 07:02:03 PM »
Thanks for the advice - I'll give it a try.  I'm assuming since nothing but the rotor seems to be affected - if I'm careful, I shouldn't screw up anything else.  If I'm lucky, I'll get it straightened up.  If not, I'm contributing to the LBS.

Offline Gough

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Re: Warped/Bent Brake Rotor
« Reply #7 on: October 01, 2008, 08:39:32 AM »
i have tried to straiten one before with some ok results, still rubbed a bit. ended up buying a new one anyway. after you handle the rotor pick up a can of brake and parts cleaner, clean the rotor before you use it, even new ones. your skin has enough oil to possibly cause problems. more enviromentally friendly way to clean the rotor after you fix it would be alcohol or warm soapy water. the spray can is good to clean the caliper and pads with out disassembly.

most bike shops can give you advice on general upkeep on you bike, lubes, cable tweeks, brake adjustments. if you want to get more into the mechanics of it check out Park Tools, the shop i worked at in Canada offered Park Tool School, great program, started with basics and went as far as complete rebuilds and wheel building. there might be a shop around here that offers that.

Offline Robobiker

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Re: Warped/Bent Brake Rotor
« Reply #8 on: October 02, 2008, 11:02:23 AM »
Before you put a wrench to it try using your thumbs to gently push the edge back in line.  This technique may take several tries, but may avoid creasing the rotor or making the warp worse.
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Offline RKL

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Re: Warped/Bent Brake Rotor
« Reply #9 on: October 02, 2008, 05:01:46 PM »
I went to it w/ a wrench last night - was able to straighten out enough to keep it from stopping free spin of the wheel abruptly - but it still has a bit of a wobble and rubs slightly.  The good news is that it's more ridable and I didn't appear to make things worse (always a plus) - but ultimately I'll end up getting a new rotor.

Again - I appreciate all the advice.

Offline Alan

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Re: Warped/Bent Brake Rotor
« Reply #10 on: October 02, 2008, 06:45:26 PM »
Did you check to make sure all the bolts fastening the rotor to the hub are all torqued down to spec?  If one or more of those comes loose it could give the illusion of a warped rotor. 

Offline RKL

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Re: Warped/Bent Brake Rotor
« Reply #11 on: October 02, 2008, 08:15:42 PM »
I think everything is still tight.  The rotor had a scratch in it centered where the bend was & I had somebody knock me hard in the real wheel as we passed on a trail at the last club ride at Boyette.  I checked the wheel after the bump - but didn't notice the rotor.  I think it was not loose - just pushed in some.  The bike is also only about 6 months old - and hopeful not loosening up already.

 

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