Input Shaft Gear 17.5°, D=30mm - not available from BMW.
Originally, this part had a 15° gear cut. This was changed in 4/1982 to 17,5°. If your bike was manufactured after 4/1982, but before 3/1985 then this part is a direct replacement, however if your bike was manufactured before 4/1982 and never upgraded to the newer design, then you will also need to purchase a new 5th gear wheel that is also cut at 17,5°. Vehicle Manufacturer: BMWApplication: BMW Airhead Models with 5 speed gearbox.Make/Model: BMW R45, R60, R80, R100Model Years: 04/1982 - 03/1985Manufacturer #: 23 22 1 242 991(See APPLICATION TABLE tab below to verify vehicle fitment )