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Old 03-07-08, 07:35 PM   #1
Bohh
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Brake Body Loose

Hi all,

I'm putting some Ultegra Brakes on my bike and can't seem to prevent the brake body from sliding back and forth when I move them. Either by hand, (pushing them side to side with my finger) or pulling the level the whole body moves which in turn makes the brake arms change position. Am I supposed to really crank down on the nut that passes through the bike from behind until the brake body doesn't move? I'm afraid to do this because the fork and seat stays are carbon. Will I crush it?

Thanks,

-Mike
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Old 03-07-08, 07:37 PM   #2
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You're supposed to be able to move dual pivots by hand. As long as they're not moving when you're braking, you're fine. The best way to center these brakes it to move it by hand not via the centering screw.
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Old 03-07-08, 09:06 PM   #3
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Thanks for the reply. Thing is though that I center the pads by hand and when I press the brake level it pulls one of the pads against the rim so that even when I release the level one of the pads is still touching, while the other pad moves away. Making the bolt that passes through the seat stay and fork snug does not prevent this. I can make it tighter, I think, however as both parts are carbon I am afraid. Am I doing this right?

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-Mike
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Old 03-08-08, 08:15 AM   #4
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Maybe it's normal?
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Old 03-08-08, 08:28 AM   #5
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What I believe you've done in install "nutted" brakes on a frame intended for recessed brake bolts.

Older nutted brakes have a 6 mm bolt that goes through matching 6 mm holes in the fork crown and rear brake bridge and are retained with external nuts.

Newer recessed mounting brakes still have have 6 mm bolts but thay are shorter and do not extend all the way through the fork or rear bridge. They are retained by a recessed long nut that enters an 8 mm hole in the rear of the fork crown and the front of the brake bridge.

If you installed the older brakes on a new frame/fork, you have a 6 mm bolt sticking out of an 8 mm hole and the sloppy fit allows the brake bodies to move around.
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Old 03-08-08, 06:44 PM   #6
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I follow what your saying. However, I don't think I'm using the wrong nuts. There is a recess for the brake bolts on both the seat stay and fork and I am using a nut that looks similar to a bullet casing. When installed the nuts are recessed inside the frame/fork. I think it may be I'm not making them tight enough, but I just want to ensure that it is common that you really have to crank them down past snug.

Thanks,

-Mike
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Old 03-08-08, 09:18 PM   #7
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Quote:
Originally Posted by Bohh View Post
I follow what your saying. However, I don't think I'm using the wrong nuts. There is a recess for the brake bolts on both the seat stay and fork and I am using a nut that looks similar to a bullet casing. When installed the nuts are recessed inside the frame/fork. I think it may be I'm not making them tight enough, but I just want to ensure that it is common that you really have to crank them down past snug.

Thanks,

-Mike
OK, it does sound like you have the correct mounting hardware. However, the nuts shouldn't have to be tightened extremely tight. Firmly hand tight using a short 6 mm Allen key should be adequate.
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