Install A Rear Disc Break And Space It To The Rotor
Article By: Daniel Donley At Pandemonium Custom Choppers – www.pandemoniumc2.com
Originally Published In The November 2012 Issue Of Cycle Source Magazine
Last month, I showed you how to correctly space your rear wheel in the chassis of a bike with a drum brake. This month I am going to show you how I install a rear disc brake and correctly space it to the rotor.
Here, we have our brake caliper bracket, a set of measuring calipers, and a set of feeler gauges
I start by installing the brake rotor on the rim and torque it to factory specs. This will ensure the rotor is true to the rim.
Measure the thickness of your brake caliper bracket. Call this measurement “A.”
Get the feeler gauges out, and pick a few. I started with .020 gauges.
With your rim lying on the work bench, install the caliper bracket on to the rotor. Now start installing feeler gauges on each side of the brake pads until you have a very snug fit to the rotor. This is done to center the caliper to the rotor.
With your measuring calipers, take a measurement as shown — call this measurement “B.” With measurement “B” in hand, subtract it from “A” and this is the length of the wheel spacer you will need to make and/or buy at your local bike shop.
I have a small lathe in the shop, so I made this wheel-to-brake caliper bracket spacer.
With your new wheel spacer installed in the wheel, now is the time to fit it to the bike chassis.
Install all rear wheel spacers and the axle into the chassis. Position your brake in your desired position. For this application, I am after the six o’clock position. I use a combination square to make the brake 90 degrees to the build table.
Next, torque the rear axle to factory specs.
Now we can see that our “A” & “B” measurements are correct. You will see a nice even gap on each side of the rotor to the brake pads. This is exactly what you are after.
Last, I have to install the brake stay rod and Tig weld the mounting tabs to the chassis. This is pretty straightforward.
So there you have it: disc brake caliper installation. I think for next month I am going to find a brake caliper off something, and show you how to make your own mounting bracket and brake stay rod on the cheap. If you have any questions, feel free to give me a shout: 419-576- 6812.