Forum menu
Building my first road bike in 20 years and struggling 🙁 I can build mtb's with my eyes shut but this road bike has been a struggle. Think I've sorted everything but the brakes which are giving me trouble. rear brake caliper keeps twisting/turning around so the brakes rub on one side. I mount it up on the frame with the caliper squeezed by hand, blocks on the rim, do the mounting nut up absurdly tight, set the blocks, set the gap and clamp the cable, operate 10 times, adjust the fine set up, operate some more and...it starts to twist around the mount! Been round that loop several times now and got frustrated so now asking for help.
nearly done apart from the brakes and a few little bits (near a steerer bung...hope head doctor was too large for the carbon steerer, needs front tyre and bar tape...then ride!)
[img] 
[/img]
You need to ad some more tension to the return spring in the caliper. On the side that is rubbing, hook a screwdriver (preferably the proper tool, but I am presuming you don't have one) into the 'loop' of the spring. Now bend the 'loop' upwards until the caliper returns evenly on both sides. You can just see the bottom of the 'loops' i am talking about in the photo [img] 
[/img]
Oh and this is the actual tool I was talking about, the area on the left hand side fits into both loops at the same time, then you can move the tool either up or down to add/remove tension
http://www.parktool.com/product/offset-brake-wrench-obw-3
calipers are shimano 105.
there is an adjustment screw that swinga the caliper around, I adjust it, operate the brake and it goes out more, adjust, operate , further out...
hence the frustration
do the mounting nut up absurdly tight,
Wrong, that'll clamp all the brakes mechanisms up. Don't know what torque settings you require, but just tight enough to stop them being movable by hand.
Ah ok if they do not have exposed spring loops, can you access the actual return spring? i.e. the arm of the spring that gives the brake tension
Ah, is that the problem then?
photo in a second.
there is one spring, not 2 by the looks
ah photo uploaded
[img] 
[/img]
the screw on the top on the side opposite the spring adjusts the tilt/twist. however, the spring side moves in and rubs on the wheel after a few operations of the brake, again and again and..