1977 R100RS Project: Check if Frame is Straight

Due to a lot of cracks in the top middle fairing panel that surrounds the headlight and the fact the upper fairing bracket had both tabs broken that secure the strap that bolts to the steering head, I wanted to check the frame to see if it is straight. I borrowed a frame jig from a long time BMW mechanic who is now retired and used it to see what’s up.  The good news is the frame is straight “enough” for my purposes. 🙂

You can read about how I did this work here.

Duane Auscherman has a nice page that describes a technique you can use to check if a frame is bent and it does not require this jig. I included a link to his web page in the above write-up.

Here are a few pictures of the frame jig in use.

Frame Jig

Frame Jig

Jig Orientation & Steering Head Bar

Jig Orientation & Steering Head Bar

Frame Jig Installed in Steering Head

Frame Jig Installed in Steering Head

Swing Arm Locating Pin Inserted In Rear of Jig

Swing Arm Locating Pin Inserted In Rear of Jig

Swing Arm Pin Centered In Right Swing Arm Bushing

Swing Arm Pin Centered In Right Swing Arm Bushing

Swing Arm Locating Pin Off Center in Right Swing Arm Bushing By 2-4 mm

Swing Arm Locating Pin Off Center in Left Swing Arm Bushing By 2-4 mm GOOD ENOUGH 🙂

2 thoughts on “1977 R100RS Project: Check if Frame is Straight

  1. Wow! Lucky you to have access to the frame jig. It would be interesting to just know the truth about the frame.

    Just a couple minutes ago I made a BIG mistake. I just finished repacking the wheel bearings on my rear wheel and while torqueing the bolts that hold the Hub and everything into place I had a thought … this should have “clicked” by now and with that, I broke a bolt off!!! I removed all the bolts but the one half that is still in the threads and must admit, I have never done something like this.

    Do you have a fix for this issue? The way it is manufactured it is not a drill it out kind of fix. How do I get the threaded bolt end out of the wheel hub? Is there a tool I must buy? Thanks for all your articles and advice.

    • Dale,

      I can feel your pain when something like this happens. I’ve not had this particular problem and at the moment, it’s hard to visualize this particular bolt as I don’t know what wheel you have. That said, I’d post this problem to the Micapeak airheads forum and see what the pros have to say.

      Best.
      Brook.

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