Here is the progress on my R27. R26 or R27? What is the difference? These were the last of a long line of single cylinder motorcycles from BMW. All were shaft drive of course. The R26 had the motor mounted rigidly in the frame while the R27 was on rubber mounts. The R26 was made from 1955-1961 when it was superceded by the R27 which was made through 1967. To learn more about the R27 click here. Both models shared most of the sheet metal and front ends. The transmissions were the same but the engines were significantly different with differing castings, generator, crankshaft, piston and cylinder. Below is what I acquired. It had lain on its side in the weather for several years and as you can see it was really rough.

After a complete disassembly and bead blasting I was able to paint the frame and fenders. Pits in the frame and sheet metal were filled with Bondo prior to painting. The tank was too far gone but I found a good one on eBay. Some tires from JC Whitney, spokes from Buchanan's and the wheels were back in shape using the original alloy rims. Luckily I had a headlight. The air cleaner, battery box and tail light were picked up in BMW Junk Yard in Karlsruhe Germany during a recent business trip. A good seat (not shown) was obtained on eBay for $45 including shipping. The wheel hubs were good as were the rear drive and transmission. The motor, well that is a different story. I am trying to get it apart but I am in need of some special tools to open the bottom end. I did find a dynamo on eBay to replace the mass of rust you see on the front of the engine. What is amazing is that all parts are readily available for the R27 from a number of sources. Notice the joint between the drive shaft and the transmission. The 250's did not use a U joint between the transmission and the drive shaft like the big twins did. There are 2 round pegs on the transmission and two on the drive shaft.  The pegs fit into 4 holes in a thick rubber disk called a Hardy wheel. The rubber disk simply flexed as the alignment between the transmission and drive shaft changed.  Crude perhaps but my BMW Z3 roadster car uses the same arrangement.

I bit the bullet and bought new internals for the motor. Mike Porter pressed the crankshaft together to install a new rod and crank pin. A local bearing shop supplied new ball bearings for the crank and cam. Steve McClintock bored the cylinder for a new piston.  Amazingly the transmission was water-free and in good nick.  New rubber motor mounts and a Hardy wheel finished the engine installation. 

In April 2005 I was essentially finished. The bike won 2nd place in the Dauphin Island Show, Vintage European class. It runs well and I am breaking it in. Like most BMWs the pick up is not remarkable but once rolling it motors on down the road just fine.  I have taken it up to 60 MPH a few times and that should be a good cruise speed when it's broken in.