Bowman made aftermarket parts for BMW motorcycles. Light flywheels, deep oil pan, big pistons, car synchronizer, carb tune, carb-sync for various models of BMW.
I must add in that I worked on BMWs with some of these products. The aluminum flywheels were well known to have the S and TDC marks 40 degrees off of where they should be. The pistons were not known to work well, as they seated in poorly. These products didn’t have a good reputation.
