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Front Brake problems...

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Old 13-07.-2004, 12:46 AM   #1
TrekDedicated
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Default Front Brake problems...

I was in an accident in which my front wheel was jammed extremely hard. Now only the left side of the brake pulls to the tire. The right side barely moves... How do I adjust this?

-also-

It may be due to the brake(s), but when I spin the wheel, after 2/3 revolutions, the brake pads grip the rims and stop the wheel..
Could it be a bent rim or what?

Thank you!
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Old 13-07.-2004, 04:50 PM   #2
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Default Re: Front Brake problems...

Quote:
Originally Posted by TrekDedicated
...only the left side of the brake pulls to the tire. The right side barely moves... How do I adjust this?
First check that everything moves freely if you wiggle it by hand, if it doesnt you need to cure whatever that's jammed first.
There is a small screw down by the brake boss which sets the return spring preload. If that doesn't help you need to loosen the brake arm to do a bigger preload adjustment. At the base of the brake boss there's usually a small plate with 3 holes in it, and the return spring is anchored in one of those. By moving the preload spring to another hole you can make a coarse preload adjustment. Some suspension forks use a boss with only one hole in it, then the whole boss needs to be turned to adjust the preload.

Quote:
Originally Posted by TrekDedicated
It may be due to the brake(s), but when I spin the wheel, after 2/3 revolutions, the brake pads grip the rims and stop the wheel..
Could it be a bent rim or what?

It sounds like it, but a bent rim shouldn't contact both brake pads simultaneously. Slacken the brake, spin the wheel and check if sideways distance fork-rim changes during rotation, if it does, then your wheel is bent.
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Old 14-07.-2004, 07:54 AM   #3
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Default Re: Front Brake problems...

Quote:
Originally Posted by dabac
It sounds like it, but a bent rim shouldn't contact both brake pads simultaneously. Slacken the brake, spin the wheel and check if sideways distance fork-rim changes during rotation, if it does, then your wheel is bent.


actually, if the rim receives a hard enough blow, the sidewalls will actually flatten outwards.

for example, they will start out like this: |__|
and end up like this: \__/

i've seen it a few times while working at the local bike shop. this could cause the brakes to be grabbing the rim at that one point. if only one pad grabs the rim at that point, the wheel needs to be laterally trued. you're local shop can do it.
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Old 14-07.-2004, 08:28 PM   #4
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Default Re: Front Brake problems...

Quote:
Originally Posted by Greg-O
actually, if the rim receives a hard enough blow, the sidewalls will actually flatten outwards.

You're right, I've had it too on a couple of occasions. But I've never seen it bad enough to stop a spinning wheel after only 2-3 revolutions, so I didn't think about it this time.
The problem I usually associate with that kind of deformation is pulsating brakes.
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Old 19-07.-2004, 02:10 AM   #5
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Default Re: Front Brake problems...

Quote:
Originally Posted by dabac
You're right, I've had it too on a couple of occasions. But I've never seen it bad enough to stop a spinning wheel after only 2-3 revolutions, so I didn't think about it this time.
The problem I usually associate with that kind of deformation is pulsating brakes.


ah, very true. i wish he would respond and tell us how he's doing!
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Old 20-07.-2004, 04:46 AM   #6
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Default Re: Front Brake problems...

Quote:
Originally Posted by Greg-O
ah, very true. i wish he would respond and tell us how he's doing!


I took it to the bike shop, they said it was really screwed up...

Thanks for all your replies!
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Old 20-07.-2004, 03:54 PM   #7
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Default Re: Front Brake problems...

Quote:
..they said it was really screwed up...


That doesn't really tell us anything, we want details!

Hope you get it fixed though.
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Old 21-07.-2004, 10:56 PM   #8
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Default Re: Front Brake problems...

They didn't tell me.

But I think it was b/c the cable was very loose/worn and the spring needed to be put back (that dog hit it hard)
I now have like 5 inches of cable extra on my front brake.
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Old 22-07.-2004, 12:01 AM   #9
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Default Re: Front Brake problems...

Quote:
Originally Posted by TrekDedicated

But I think it was b/c the cable was very loose/...I now have like 5 inches of cable extra on my front brake.


If it was a simple case of cable slippage, didn't you notice that your brake lever was bottoming out against the handlebar?
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