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Old 12-29-10, 09:59 PM   #1
chadwebster
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right way to adjust sidepull single pivot brakes ?

i have been centering my brake calipers but turning the pivot bolt as seen in the picture. My friend told me that i should be adjusting it by the nut by the spring in which case i would need to take the break off the bike. Who is right and if i am wrong, am i doing any damage? it seems like a PITA to remove the brakes just to center them when my way works fine004.jpg
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Old 12-29-10, 10:46 PM   #2
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Look behind the brake body and look for what appears to be 2 flat sides. This is where you use a 13mm cone wrench or a very narrow wrench to adjust the brake. The nut that the wrench is on (in the picture) is there to lock the other nut in place to keep the brake caliper together. Tighten the outer 2 nuts too much and the brake will not work properly. Too loose and the caliper body will have excess play
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Old 12-29-10, 10:54 PM   #3
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The nut you are turning in the photo is for adjusting the clearance between the brake arms. It is prevented from rotating on the pivot bolt by the lock nut being tightened against it. If you use it to center the caliper, you risk changing the arm clearance and possibly loosening the nuts on the pivot. The boss that holds the spring often has flats on it which can be turned with a cone wrench. If not, you can tap or lever the spring to center it.
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Old 12-29-10, 11:07 PM   #4
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Both posts above are correct. Tighten the brake on the frame and use the outer nut and locknut to reset the side play on the arms for the lease amount of play with nice action and make sure the two nuts are well locked to each other so they don't move.

Then loosen the mounting nut and center the brake use the flats on the mounting block.

Two added comments, friction where the legs of the springs meet the arms can cause changes in centering and make you crazy, so put a drop of thin oil back there on both arms. The other thing that can make you crazy is the tendency of the housing loop to push or pull the arms off center. Measure the housing loop (or slide it along the frame) for the most neutral length so it doesn't move the arms before centering.
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Old 12-29-10, 11:26 PM   #5
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And if you can't get at the flats, you can just pry out the spring and tweak it to centre in a pinch.
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Old 12-29-10, 11:31 PM   #6
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And if you can't get at the flats, you can just pry out the spring and tweak it to centre in a pinch.
if there are aren't flats, or you don't have the right tool to access them. Don't bend the spring, but improvise something that hooks under one side and allows you to lever the brake around using the bolt as a fulcrum. Loosen the mounting nut, and use your new lever to hold the brake centered while you tighten it
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Old 12-29-10, 11:42 PM   #7
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On cheap single pivot side pulls , we would use a brass punch
[softer than the spring steel, so no damage to the spring itself]
and tap on the doubled loop of the spring with a hammer,to slightly rotate the spring center carrier
that center bolt holds the brake to the frame on one side,
and has the 2 parts of the brake caliper on the other.
and tapping on it was sufficient to tweak the re centering back.

tightening the nut that holds it onto the frame has the tendency to rotate the bolt itself as you tighten it.
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Old 12-30-10, 12:09 AM   #8
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what if i loosened the recessed nut on the other side of the brake bridge, squeezed the brakes and then tightened the nut back up again?
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Old 12-30-10, 01:27 AM   #9
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Originally Posted by chadwebster View Post
what if i loosened the recessed nut on the other side of the brake bridge, squeezed the brakes and then tightened the nut back up again?
Ehhh.. This tends not to work for me. Because when you tighten the recessed, you'll end up twisting everything around and it'll be off center. What I do it jam one brake pad against the rim, so when you'll tighten the nut you'll balance that out and (hopefully) end up with centered calipers.
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Old 12-30-10, 10:52 AM   #10
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Recall seeing a star shaped spline substitute for the spring carrier flats on some Shimano made brakes ,
I suspect shimano made a proprietary service wrench, to fit that..
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Old 12-30-10, 11:10 AM   #11
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Oh and think about adding a star shaped grip washer between the brake and the frame .
Tullio Campagnolo made a special one [#2041] that was part of their side pull brake installation package,
ones from the hardware/auto parts store may do.. they have for me..

external star type..
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Old 12-30-10, 06:05 PM   #12
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thanks for the help guys, i just tore the brake calipers apart, cleaned, lubed and resembled with new brake cables and pads and everything is working great
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