How do I properly adjust my side-pull brake?

[todhunter]

Just put my Swingbike together last weekend and it has a Weinmann 810 side-pull caliper on the front. When riding the bike around the right side of the brake (viewed when seated on the bike) drags on the rim unless I reach down and pull everything to that side, then it's fine until I grab the brake again. I did some quick research earlier this week and I took the brake apart, cleaned everything up, then greased and reassembled and it still dragged. Next I tried taking it apart again and bending the spring arm out on the side that drags. It got a little better after bending it more and more, but it still doesn't release evenly and will sometimes drag.

Anyone got a tip or suggestion for getting the brake to not drag and/or release evenly?

 

[deorman]

Assemble and adjust the brake distance with the nut loose enough for the brake to swing from side to side. Using a "third hand" bicycle brake tool or the brake lever, close the brake on the rim. Make a pencil mark on the pivot and one in line with it on the frame bridge. Take apart the brake and use a big flat screwdriver in the spring slot to hold the marks inline as you tighten the nut. Reassemble and lever and release the brake. If the brake releases more on one side, turn the pivot towards the other, using the pencil marks to observe change.

 

[RustySprockets]

It isn't uncommon for caliper brakes to favor one side or the other. I simply loosen the mounting nut and shift the assembly slightly toward the side that drags, then tighten the nut and observe the result. You'll eventually find the sweet spot. Another thing to check is that the rim is properly centered in the fork.

 

[user 135]

Don't loosen anything. You just need to tweek the spring. The easiest way is to use a Offset Brake Wrench from Park Tool.
www.parktool.com/blog/repair-help/sidepull-brake-service

But you can also just take a flatblade screwdriver and hammer to adjust it. Place the screwdriver blade on the top side of the spring opposite the side that is dragging. Tap it a couple of times with the hammer.

 

[mikeeebikey]

Great post above.

 

[todhunter]

Thanks for the tips, guys! I will try some of these out tonight.

Another related question: Does anyone know the mounting bolt length on the rear Weinmann 810's? The reason I ask is that the caliper I have (pretty sure it's a front due to bolt length) has a mounting bolt so long the previous owner has stuffed large nuts in to act as spacers so that the real nut still has threads to bite down on. I'm wondering if I should actually be using a rear 810 up front...

Sorry for the crummy picture:

 

[RustySprockets]

Yup, that looks like a front unit, designed to pass through the much deeper fork crown rather than the brake bridge. Typically, this installation includes an unthreaded spacer with a curved face that matches the shape of the bridge and provides a flat shoulder for the locknut to seat against. You don't have that here. These parts can likely be made to function, but getting them to hold the adjustment could prove troublesome.

 

[todhunter]

So do you think a rear 810 will work better here?

 

[user 135]

Yes....use a front on the fork and a rear on the brake bridge. Make sure it has the curve faced spacers thought as it helps the calipers stay aligned.

 

[Sinner4]

Perfect, I think I have needed that tool about a 1000 times.

 

[alecw35]

weinmann and other brakes of a similar style had different length axles. Its fairly easy to take parts from other manufacturers and build them up together.
Weinmann being European will have a 6mm thread. Some brakes might not be metric, tho. Strumley Archer chrome steel brakes that are used on a lot of old Brittish bikes, spring to mind. Tho they are designed differently than the Weinmann sidepull brakes