Just pulled a Dia Compe N500 front brake off a Raleigh Technium 440 so I can use it on my Gran Turismo. There are two nuts in the front -- one is the lock nut and the other (a much thinner nut) is for adjusting the spring tension (I think). first question: what kind of wrench do you use on the thinner nut? I don't have anything that thin. Second: how do you adjust the distance of the brake pads from the rims? When I try to center the brakes by holding them with my hand and tightening the nut on the back of the front bridge, the brakes end up with one side working fine and the other pad being too close to the rim. Thanks!

The two nuts adjust the play in the arms. The outer locks to the inner.

The distance of the brake pads to the rims is adjusted by tightening the cable, and slightly by an adjuster if one exists.

The brake shoes are centered on the rim with flats on the bolt with a cone wrench, if they exist, or by striking one side of the spring near the bolt with a punch and a hammer to move the entire brake if they don't.

The brakes should have a knurled knob where the cable attaches. Back the knob out a little to adjust the distance from the pad to the rim.

As dbakl wrote, the bolt usually has flats just in front of where it goes through the fork (or behind the brake bridge on the rear brake). My Campy brakes have a 13mm flat section there. I use a Park offset brake wrench OBW-1 to grab the flats and center the brakes. That rotates the entire assembly.

BTW, I don't think Park makes the OBW-1 now. It was perfect for the 80's Campy style sidepull brakes, but I guess they redesigned the tool for newer brake styles. A thin cone wrench will work, it's just not as convenient.

https://www.mrstevesbikerat.com/store..._22992159.html

-Kurt

Good find, Kurt. The park Tool site doesn't list them now.