Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-31-10, 08:59 PM   #1
auchencrow 
Senior Member
Thread Starter
 
auchencrow's Avatar
 
Join Date: Apr 2009
Location: Detroit
Bikes:
Posts: 10,330
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Centering side-pull brakes

Iíve done this many times, but I still canít seem to get it right (perfect) Ė i.e., centering brakes with any side pull caliper that does not have a secondary mechanical centering device.

Case in point: I just upped the spoke tension on a rear wheel (to obviate an annoying creak), and after re-truing the rim, I can only effect about a 1 micron gap between the left brake shoe and the rim, with about 7/32Ē gap to rim at the right side.

- Iíd like to even this up, but after using my 3rd hand tool and resetting the caliper at the brake bridge , I just get the same result, at least once I squeeze the brake lever. - Ditto for trying to budge the caliper spring over.

Is there some special trick to centering these things? The caliper at hand is a Weinmann 605, but Iíve had the same issue with other side pull brakes as well.
__________________
- Auchen
auchencrow is offline   Reply With Quote
Old 07-31-10, 09:06 PM   #2
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Bikes:
Posts: 7,912
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Quote:
Originally Posted by auchencrow View Post

Is there some special trick to centering these things? The caliper at hand is a Weinmann 605, but I’ve had the same issue with other side pull brakes as well.
First things first: make sure the brake cable and housing is the correct length, i.e. it doesn't apply any rotation to the caliper.

With those particular calipers: http://velobase.com/velobase.com/Vie...1-ad1bd9de6a06 , there's a special wrench that grabs the exposed hex-shaped portion of the center bolt to make for easier centering. Since I bet you don't have that wrench, try loosening the caliper, pulling the left shoe all the way over, then tightening the caliper again. Squeeze the brake lever a couple times and see where the caliper centers itself. Repeat until you're satisfied or insane, whichever comes first.

With very cheap calipers, we used to get them snug and then use a punch on the spring close to the center bolt. This is a rough method of rotating the center bolt, and it tends to bend the spring. However, sometimes it's the only method that works.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline   Reply With Quote
Old 07-31-10, 11:55 PM   #3
auchencrow 
Senior Member
Thread Starter
 
auchencrow's Avatar
 
Join Date: Apr 2009
Location: Detroit
Bikes:
Posts: 10,330
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Thank you Jeff - I thought the center hex thing might do something, but you are right - I did not know what, and I have no such tool.

I have tried loosening the caliper and pulling the left shoe all the way over. It never seems to slake off any of that extreme bias after squeezing the brake lever. I've had other calipers do this, but this particular caliper seems even more difficult. - I think my only other option may be to bend the spring a little, but this is a little touchy I'm sure.
__________________
- Auchen
auchencrow is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:35 AM.