Darryl.Richman's picture

I am still in Germany. I've made a couple visits already, as you know from my last post.

Yesterday I was in the Allgäu, which is a lovely area of rolling dales that runs from the Austrian border and Mad King Ludwig's famous Neuschwanstein dream castle in the south, north to Ulm. It is Germany's breadbasket, with lots of agriculture and little development. The A7 autobahn, which runs down the western edge, was only just finished a few years ago.

On the eastern side of the Allgäu is the small town of Krumbach; and a tiny hamlet north of Krumbach is Oberegg, where Dreher Oldtimerteile is located. Philipp Dreher is a BMW enthusiast whose main business is farm equipment, though he has in the last few years acquired laser cutting equipment and now makes a variety of sheet metal products. When Joseph Kast retired from selling vintage BMW parts, Philipp bought his business, and now prewar BMW parts fill the shelves in the last few rows of his warehouse.

My big scores were a spare clutch plate, a set of roller bearings for the steering head (to replace the loose ball bearings that are surely still inside my steering head), a complete set of spare gaskets and some carburetor jets. These parts were generously donated to Team Boxer Rebellion in exchange for space on the side of my Sprinter van as TBR travels to the east coast and back again to San Francisco.

Vist my website to see the growing list of donors to Team Boxer Rebellion, and to see how you can participate! You'll see that several well known and regarded vendors and service providers are helping me, and I urge you to support them as well.

I had word back from Uli Döderlein of Bayrische Magnet Zünder about the spare Bosch D2A magneto I left with him. Sadly, just about everything I didn't replace before needs replacing. These are, naturally enough, the most expensive pieces: a new generator armature, a new magneto coil, a new cam ring and a new condenser, not to mention a handful of specialty screws and other bits and pieces. This will not be cheap, but I have total faith in Uli's ability.



andres  / grabacion's picture

yo quiseiera tener una de estas jjaaaaaaaaaaaaa gracias

Ich suche Teilen...

Jim Hansen's picture

"...lovely area of rolling dales..."

It's a tough life, but someone's gotta do it.

Not that the bike market

castors's picture

Not that the bike market isn't zooming along itself. Ron Christensen, of Mid-America Auctions, whose Las Vegas sale every January moves 400 to 500 bikes in a single weekend, reports that sales have nearly doubled since 2000.

Final Drive Repair

Marc St-Pierre's picture

Darryl; just to back-track a bit; how did you end up repairing the final drive? Was there any modification to the original design, like a spot weld to hold it in place, or even a machined keyway and key?

Old apprentice machinist's joke: Question: What's a keyway? Answer: About an ounce, ha, ha... (Feel free to groan.)


Final Drive Repair

Jim Hansen's picture

I'm also very curious about the final drive repair. Relying on an interference fit for an area with such heavy loads seems kind of shaky. Was this a BMW design error, or did the final drive just need a tighter fit? I can't sleep at night, thinking, wondering, pondering about this...

Interference fits

Darryl.Richman's picture

BMW has long relied on these in a number of critical places. Some joints in the drivetrain are made with tapers, such as the flywheel to the crankshaft and the output flange to the end of the output shaft in the transmission. But the crankshaft is pressed together with just interference fits between each web and the crank pins; there are four of these fits. The cardan brake drum is press fit to the drive shaft. In the final drive, on a stock solo machine, the pinion is pressed onto the drive shaft, and the ring gear carrier is pressed onto the short shaft that drives the rear wheel. It drives the wheel with a hub that is pressed on, and into which four dogs are pressed.

Clearly BMW felt that an interference fit was entirely sufficient, not only for the 12 hp of an R52, but the 24 hp of an R63. Because this bike is 85 years old, I suspect that the fits may not be as tight as they once were, since they have probably all been pressed apart and back together more than once.

--Darryl Richman
"Bling is not made in Germany" --OTL, 12/05

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