Tag Archives: 1973 BMW R75/5 Rebuild Blogs

1973 BMW R75/5 Rebuild: Install and Align Front Forks

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So, now I’m ready to install the front forks and align them. You can read about how I did that work here.

Earlier, I rebuilt the front forks, refinished the sliders and replaced the steering head bearings. I also polished the steering damper knob and added a modern BMW emblem to the center of the knob. You can read about how I did that here:

It took me awhile (about 2 weeks) to complete the fork tube alignment process. I had to adjust the forks to get them parallel in both the X and Y Planes. And then they went out of parallel as I assembled the upper top brace and the headlight ears.  Some investigation showed that the rubber gaskets on the headlight ears changed the alignment of the upper brace. Small changes create misalignment, so patience is a virtue.

I’m pleased with the final product both in looks and improved alignment.

Here are a couple pictures from the write-up.

Steering Head after New Bearings Installed

Steering Head after New Bearings Installed

Fork Sliders, Top is Right Side, Bottom is Left Side with Axle Clamp Allen Head Screw

Fork Sliders, Top is Right Side, Bottom is Left Side with Axle Clamp Allen Head Screw

Forks Mounted and Lower Sliders Removed

Forks Mounted and Lower Sliders Removed

Positioning Glass on Fork Tubes

Positioning Glass on Fork Tubes for Y-Plane Alignment

Fork Alignment in Y-Direction

Fork Alignment in Y-Direction

X-Plane Measurement at Bottom of Tube

Fork Alignment in X-Direction

Clamping Forks Below Yolk to Adjust X-Plane Alignment

Clamping Forks Below Yolk to Adjust X-Plane Alignment

Lowers with Fork Brace Installed

Lower Slider with Fork Brace Installed

Steering Head Grunge & Damper

Original Steering Head Grunge and Scratched Damper Knob

Polished Damper Knob, Emblem and Polished Upper Brace

Polished Damper Knob, Emblem and Polished Upper Brace

Finished Upper Fork Brace with Damper and Handlebar Mounts

Finished Upper Fork Brace with Damper and Handlebar Mounts

Finished Upper Fork Brace with Damper and Handlebar Mounts

Finished Upper Fork Brace with Damper and Handlebar Mounts

1973 BMW R75/5 Rebuild: Some Refinishing Information

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I’ve had several questions and Email about how I refinish the rough aluminum casting on the engine, transmission and rear drive and also some questions on how I got the carburetors to look shiny and new again.

NOTE: Refinishing is not rebuilding. Refinishing is restoring the surface of parts to “like new” condition. You are removing crud, stains, grime, dirt, grease, bugs, corrosion, tar, mud and old gasket sealer that have frequently been baked on for 10, 20, 30 or more years. It takes PATIENCE. It is applied Zen Smile

So, I put this together to illustrate some of the techniques I use on this project:

And, some After pics from the write-up:

Polished Hubcaps

Polished Hubcaps

New Rubber, New Spokes & Polished Wheels

New Rubber, New Spokes & Polished Wheels

Polished Engine

Refinished Engine Case and Timing Cover

Refinished Left Side

Refinished Transmission

Cleaned and Polished, Outside View

Cleaned and Polished, Outside View

Powder Coated Right Control Perch with Polished Lever

Powder Coated Right Control Perch with Polished Lever

1973 BMW R75/5 Rebuild: Installing Rear Sub-Frame, Shocks, Key Lock, Seat Latch

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This bit of work finishes up the rear end until I install the fenders and seat. Those will wait for me to strip and paint the body work.

Here is a write-up on this work.

The key lock and seat latch can be confusing to get in, so I took some extra pictures of the assembly process.

Here’s a couple pictures from the write-up.

Rear Frame

Rear Sub-Frame, Upside Down

Marking on Right Shock Pre-Load Adjuster

Marking on Right Shock Pre-Load Adjuster

Securing Shocks by Lower Shackle

Securing Shocks by Lower Shackle

Right Side Sub-Frame Bolts Installed

Right Side Sub-Frame Bolts Installed

Seat Latch and Lock Hardware

Key Lock and Seat Latch Hardware

Attaching Lock Retaining Ring with Screw

Attaching Lock Retaining Ring with Screw

Here is the rear end of the bike when I disassembled it.

Rear End Disassembly

Rear End Disassembly

Supporting the bike before rear end and swing arm removal

Rear End Dissassembly

And how it looks now. Major improvement 🙂

Rear Shocks Installed

Final Product

Lock & Grab Handle

Key Lock and Grab Handle Installed

1973 BMW R75/5 Rebuild: Rear Brake Installation

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Well, I now have the rear brakes installed and am working on getting the rear sub-frame on the bike. When I get that done, I’m going to move on to the front forks and steering.

Here is the write-up on installing the rear brakes, rear brake pedal and mounting the polished rear wheel with the new stainless steel spokes and the powder coated battery box:

Here’s how the bike looks at this point.

Rear Brake Pedal and Wheel Installed

Rear Brake Pedal and Wheel Installed

Final Result

Final Result

1973 BMW R75/5 Rebuild: Install Swing Arm and Rear Drive

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After I got the engine and transmission installed in the frame, it’s time to add the swing arm and the rear drive. Here is the write-up I did for this part of the project.

And, you can find the write-ups for the engine and transmission installation work here:

Here are some of the pictures from the write-up.

Rear of Transmission & Drive Shaft Coupling (Upper Right)

Rear of Transmission with Drive Shaft Coupling (Upper Right) and Frame Protection

Powder Coated Swing Arm with Drive Shaft Inside

Powder Coated Swing Arm with Drive Shaft Inside

Swing Arm Pivot Pins, Lock Nuts and Plastic Caps

Swing Arm Pivot Pins, Lock Nuts and Plastic Caps

Swing Arm Boot - "OB" EN (Top) on Round Section

Swing Arm Boot – “OB” EN (Top) on Round Section

Measuring Swing Arm Gap to Center the Swing Arm

Measuring Swing Arm Gap to Center the Swing Arm

Sitting on Rear Tire to Tighen Drive Shaft Bolts

Sitting on Rear Tire to Tighen Drive Shaft Bolts

Swing Arm and Rear Drive Installed

Swing Arm and Rear Drive Installed