1983 BMW R100RS Install Rear Brake System

Posted on August 8, 2020 by Brook Reams

I’m converting this RS model to a RT. The only difference in the brake system is the length of the hose from the front master cylinder to the front brake line splitter underneath the gas tank as the RT handlebars are wider so that hose is longer. The rear brake system is the same on both the RS and RT models

I previously rebuilt the two front and one rear calipers and rebuilt the rear master cylinder. The front master cylinder was so badly corroded that I replaced it along with the entire right handlebar perch. I also installed the three disk brake rotors on the newly powder coated wheels. You can read about how I did that work here.

Here is the documentation of how I install the rear brake system and a short video summary of the procedure.

34 BMW 1983 R100RS Install Rear Brake System

VIDEO: 1983 BMW R100RS/RT Install Rear Brake System

The master cylinder in on the right side while the rear brake caliper is on the left so there is a long steel brake line between the master cylinder and a bracket on the left, lower frame gusset where the flexible brake hose from the caliper attaches to the steel brake line. That’s a long run of brake line and I use my “Air Zapper” to help pull the air out of the line.

“Air Zapper” Vacuum Brake Bleeding Parts

I finished up bleeding the rear brake system by pumping the rear brake pedal and opening and closing the caliper bleed valve to get the last bit of air out of the system. I now have a solid rear brake all set to stop.

Rear Caliper Mounted And Ready To Stop

So next up is installing the front brake system.

1983 BMW R100RS/RT Install Electrical System

Posted on August 1, 2020 by Brook Reams

I’m converting this bike from and RS to an RT model, so there are some changes associated with the RT model, but the electrical system changes are limited to changes in cable lengths for the handlebar switches.

This document references other documents previously published as well as containing new material.

61 BMW 1983 R100RS/RT Install Electrical System

The idea is to consolidate information about how I install the electrical system on the bike in one place. I also include the results of my testing of the electrical system, the problems I found and how I fixed them. I hope this is helpful.

Here is the Table of Contents

1983 BMW R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

Posted on August 1, 2020 by Brook Reams

On this model/year bike, it’s critical to shim the oil filter canister correctly to avoid loss of oil to the engine. I show how I do that. I also show how I install the oil cooler, thermostat-oil filter cover, and the shims and o-rings to properly seal the cover and oil filter canister.

11 BMW 1983 R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

Here is a short video summary of how I do this work.

VIDEO: 1983 BMW R100RS Shim Oil Filter Canister, Install Oil Cooler & Filter

Here are some pictures of the work.

Oil Filter Parts Detail

Simple Spreadsheet To Determine The Required Number Of Shims

Cleaned Up Oil Cooler And Hoses

Oil Cooler Installed On Frame Tube

Oil Cooler Hoses Attached To Oil Filter Cover With Built In Oil Cooler Thermostat

Oil Cooler, Filter and Filter Cover Installed

1983 BMW R100RS/RT Install Transmission And Handlebar Perches, Switches & Cables

Posted on July 22, 2020 by Brook Reams

I installed the transmission in the frame, mounted it to the engine block, connected it to the drive shaft, assembled the clutch throw-out mechanism, attached the speedometer cable, the neutral switch wiring and the foot shift.

I also installed the handlebars, perches, switch assemblies and routed the cables. Since I am converting the RS to and RT configuration, the switch wiring and cables are RT length.

You can read about how I do this work here:

I also made a video summarizing the transmission installation.

VIDEO: 1983 BMW R100RS Install Transmission

Some pictures of the work.

Needs Gear Lube (Red Tape On Fill Plug)

Clutch Throw-out Mechanism Parts

Parts For Connecting Transmission Output Flange To Drive Shaft and Swing Arm

Rotating Input Shaft In Small Increments To Align Splines With Clutch Splines

Foot Shift Lever, Linkage and Left Foot Peg Installed

Right Handlebar Control Hardware

Left Perch, Cables And Switches Installed

Right Perch with Front Brake Master Cylinder and Parts

Right Perch, Cables & Switches Installed

Handlebar, Perches, Cables And Switches Installed

1983 BMW R100RS Rebuild Transmission

Posted on July 10, 2020 by Brook Reams

This is the second time I have worked on rebuilding an airhead transmission. That should make it clear that I am an amateur, not a professional, when it comes to doing this work. I would not attempt to rebuild a transmission unless I have access to experienced, long time, airhead mechanics. I’m very fortunate to have access to three of them. And, I plan to continue rebuilding transmissions on my own projects, so the considerable investment in tools will get amortized over the future projects.

NOTE:
I would not recommend that you rebuild your transmission unless you have completed multiple bike rebuilds, have invested in precision measurement tools and specialized transmission tools, and expect to rebuild multiple transmissions. The cost and risk are too high if you just plan to do one transmission. I would recommend you have your transmission rebuilt by a reputable builder such as Tom Cutter at Rubber Chicken Racing Garage in Pennsylvania, Matt Parkhouse ([email protected]) in Colorado, Bob Clement at Bob’s Motorwerks ([email protected]) in Montana, and Bud Proven at The Nickwackett Garage in Vermont.

This transmission has over 83,000 miles on it. That said, it was in good condition when I had the parts inspected by an airhead mechanic. So that’s a good thing.

I wrote five documents showing how I do the work.

And, I shot five YouTube videos summarizing the work in each document.