BMW Airhead Clutch and Transmission Install - Custom BMW R90/6 Bobber

Feeling refreshed from my recent beach vacation (check out the video: • Video ) we dive back into the custom BMW R90/6 Bobber by installing the new clutch and the refinished transmission.
The clutch on airheads are more like an automotive clutch than the units you'd typically find on a motorcycle. Rather than a series of friction discs and metal discs held in a clutch basket, the airhead uses a dry clutch held between a pressure plate and thrust ring by a spring plate. It requires the use of a centering tool to ensure the transmission input spline engages easily during install. Rather than pay good money for a pre-made tool, the little benchtop lathe makes a part that serves the same purpose for the cost of a little 7/8" aluminum rod.
The transmission itself is a bit like an aircooled volkswagen's in that it's simply held in place by four bolts. Then it's simply a matter of bolting down the driveshaft.
While we're at it we throw in the starter motor and a few other little pieces. This video is short and sweet and shows the process.
Want to see more of the Custom BMW R90/6 Project I'm working on? Check out the playlist here:
• BMW R90/6 Custom build
I'm on Instagram @roodlum / roodlum
Parts made right here in Rochester, NY are available here:
shop.themotowo...

[@chrisblenkinsopp8588]

What was the thing you took out of the fridge? I presume that was to shrink it for a tight fit...

[@roodlum]

That's correct. That's a reed-valve style crankcase breather.

[@davidcooper729]

Thanks for all the videos, crazy helpful! I’m confused what to do with my breather. Can you explain what you did with yours?

[@roodlum]

Sure, I updated the breather to the later reed style valve. Not strictly necessary on a street bike but I figured I'd do it while the motor was apart. Supposedly it will mean less oil consumption at high RPM, and considering how oily the right head was compared to the left (the breather hose dumps to the right) I thought it would be a good idea to change the valve out.

[@441rider]

Cool vid, what were the tool specs for my lathe task? :)