Bicycle Mechanics - Shimano brake adjustment.

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View Full Version : Shimano brake adjustment.


Bobsled
12-20-01, 11:04 PM
New to shimano so I need help with this one. Park makes an offset adjustment wrench for Campy brakes so that when they're all tighten down and they end up being offset (closer to one side of the rim than the other) you just take your offset wrench and center the brake calipers without having to loosen it because the force of tightening them almost always leaves them un-centered. Anyway, my question is can you do this with shimano brakes (ultegra) too and who makes a tool for this (already visited Parktool.com and couldn't find any)?


Geronimo
12-21-01, 02:05 AM
are they the Ultegra dual pivot brakes? the set screw on top of the middle piece of arm (hard to describe) will adjust the spring tension and help to center the brake arms. You can also take them loose and do the gross centering, retighten, and use the set screw to fine tune. Shimano's Euro site has much better tech info than the US site.

http://www.shimano-europe.com/cycling/phpimages/productserie/service_pdf/BR-770065005500%20%28EN%29.pdf

see step 4

hope this helps

RainmanP
12-22-01, 11:37 AM
Bobsled,
I am nut sure about Ultegra, but I'll tell you about my two different sets of different vintage 105 brakes. One set, that are, I believe, 8-speed, has the screw I think Geronimo is describing. A small philips head screw out at the corner on the opposite side from where the brake cable attaches. That is the fine centering adjustment. The other set on a 12 speed from the late 80s has kind of a conical 12 mm hex (outide hex, not Allen head). This is the head of the mounting bolt, but is only an incidental part of the mounting system. According to older repair manuals you use it to adjust the centering by putting a wrench on it and turning the whole mechanism by rotating the bolt. Easy does it, you only need to move it a little. With this setup you don't need to loosen the mounting bolt. I'm not sure if I am doing a good job of describing it. Let me know if you think you have this type of setup and need more guidance. This type can be confusing because the single mounting bolt, a nut and a treaded sleeve type of mounting nut are actually fulfilling three different functions - appropriate tension controlling the brake arm pivot, centering, and mounting the brake mechanism. Each function needs proper adjustment for the brakes to work well.

Mike and others, have I described this more or less correctly? I only recently began to understand how this type of brake mechanism goes together and works, and I'm still not sure I fully understand.
Regards,
Raymond


Bobsled
12-22-01, 06:03 PM
Thanks guys. I'm not sure if it's dual pivot. It's a 2001 model so I would think it is (isn't that the only way they make them?). Anyway, they have (adjustment) screws everywhere. I'll try your recommendations then read the owner's manual if those fail. The shop I bought the bike from was good enough to hand them all over to me.

Bike Spokesman
12-26-01, 06:28 PM
A 2001 brake will definately be dual pivot, and if you look at the third piece in the brake construction from above, the adjustment screw should be right on the middle peice.

Good luck

Bobsled
12-27-01, 10:49 PM
BS,

That did the trick. Thanks all.