Centering Side-Pull Brakes
 

http://bikeforums.net/attachment.php...hmentid=330525

I'm a complete noob when it comes to bicycles and I'm having trouble centering these side-pull brakes.

I tried playing around with the lock nut up front and I ended up snapping these little plastic spools off of the spring, and the ends of the spring came out of the arms. I was able to pinch the ends of the spring together and place them within the arms. I definitely learned my lesson and won't try to repair anything I'm completely clueless about. However, I'm wondering, were these small plastic spools that slid onto the spring and made direct contact with the arms essential for the brake to function safely?

Also, how do I go about centering these side-pull brakes?

I know that my lack of knowledge and terminology in regards to bicycles are going to make my post difficult to understand. Sorry in advance :lol:

Mounting bolt tight?, you can loosen it and by holding them centered as re-tightened, re center the brake..



+ adding a star washer digging into the fork and the center bolt on the front side should keep it centered.



my guess the plastic pieces were bushings so springs slide ..

but my old side pull brakes dont use them , so it has to be a guess ..

There are several ways to center side-pull brakes. Probably the easiest to explain, and a very old method, is to use a hammer and flat punch or similar, explained at: http://davesbikeblog.squarespace.com...ll-brakes.html.

Most mid-level or better side pull calipers have wrench flats on the pivot bolt to accept a cone wrench for centering the caliper:

http://www.os2.dhs.org/~john/brake-center1.jpg

http://www.os2.dhs.org/~john/brake-center2.jpg

The plastic sleeves on the spring aren't critical to the brakes operation, but they make it much easier to keep centered.

As brakes open an close the spring slides up and down the arm slightly. Friction between the spring and arm doesn't effect braking at all because it always self centers against the rim, but it will affect how they open. A little bit of friction is enough to cause the opposite arm to open more.

Keep the place where the spring oiled and they'll be fine, but it'll attract diet. The plastic sleeves allow sliding without attracting dirt.

Yes, that's why I said there are several methods, but given the OP's equipment I doubt very much that his calipers have centering flats.

before you adjust your berake
make sure the axle is firmly and fully seated in the dropouts

if the axle is not ompletely int he dropouts
then the wheel will be in crooked
and every brake adjustment you make will be referenced to the croked wheel
then when you remove and reinstall the wheel
the brakes will be crooked again

The front lock nut holds the arms together and is not to be used to centre the brakes... after setting the brake in place by tightening the rear nut you can use the hammer / punch method for brakes with no wrench flats to get the brake into proper alignment.

This method was extremely simple and very effective!

Thank you everybody for your contributions.

Half the work on keeping sidepulls centered on a frame should to make sure that your brake cable routing and length will excert the least amount of pulling or pushing loads on the caliper when the handlebar is turned through it's maximum angles fron=m the frame....but some brake calipers do seem to resist centering despite any sort of adjustment you may do to it or the cables (I remember Weinmann sidepull brakes used to be stubborn for me back in the 80's. I pretty much had to adjust them for dentering after every ride.). But do check your cable length and routing very careful, and you will be at least half way to getting your brakes to remain centered on you bike...

These are old single pivot brakes. it just takes experience to get better at it. I tried 2 teethed washers, between the fork, and rear brake bridge and the nuts/washers. Someone here once mentioned that. When I tighten the brakes. I put a dime or washer under the brake pads, before putting the third hand on the calipers. Also Sheldonbrown.com // Chris

As long as people are mentioning other methods there is one that does indeed involve the front nuts. One locks the two front nuts together firmly, making sure that the pivot is properly adjusted. Then you put one wrench on the rear nut and the other on the locknut if moving the caliper clockwise and on the pivot adjusting nut if moving counterclockwise. Allows very accurate adjustment to where you want the caliper to sit.

Thank you for this.