This is one of those things I try to do to every BMW motorcycle I rebuild.
This area is cracked on nearly every frame I tear down. It is the rear foot brake area which also is the muffler / silencer hanger, and where the passenger foot pegs attach. This frame is a 1978 BMW R100s. If you are considering rear sets on your bike that attach to this section, then I HIGHLY RECOMMEND doing this procedure.
cracked tab near rear foot brake pivot hole on BMW airhead framecracked tab near rear foot brake pivot hole
cracked tab near rear foot brake pivot hole on BMW airhead frame
New piece of metal to weld onto the old cracked section to reinforce the area making it MUCH stronger and no longer prone to cracking.
Welded metal onto the rear foot brake section of a BMW R100S
Finished powder coated frame with the welded metal. This area is out of sight to most people unless they take the rear tire off.
I can’t remember the condition of this final drive when I assembled my 77 R100s back in 2003. When I had my rear tire replaced recently, I noticed how terrible the splines are. The splines on the wheel are better then the final drive but they will need replacing someday too.
I found this drive with the same ratio and cleaned it up and replaced the spline. Now it is time to swap the drives.
While it is apart, I am taking the opportunity to pull the tranny back and lube the clutch splines as well.
Back to Beemers…
I’m working on a project bike for a friend and had the items powder coated satin black. I’m very excited to see how this bike will turn out.
And yes, I have a very messy garage/workbench at the moment.
I removed the wheel bearings and the races with lots of heat, and the help of a press.
Then went to the powder coat shop and gave them the masking instructions.
Here are some photos of the install.
Not pictured is the process of checking and testing the bearings in the race to make sure they spin smoothly.
If not, clean them, re-test, and clean them again, etc…
Then grease ’em good!
Also not pictured is the process of cleaning the inside of the hub REALLY well. Especially since they were sand blasted.
And.. then there is the process of pre-loading the bearings, freezing them for a day, heating the hub and then ‘plop’, you are done.
Bearings from when I pulled them from the hub.
Preloaded bearing stack. I have a piece of steel pipe that I put on the other side of the stack with the axle to help with the preload.
A nice propping set up for when it is all heated. These are damaged cork Yoga blocks that a yoga company couldn’t sell. I happily found a home for them in my garage and they come in handy!
Frozen bearing stack and axle dropped into that toasty hot hub.