Originally Posted by cele0001
6 speed has 19 mm of spline length available. It does not use 6 mm, so only 13mm are actually carrying the load.
All of the old parts I have here show about 16mm of engagement, with 4mm unused spline in the hub. The R1100 5-speed has 18mm engagement.
FWIW the input shaft for the Hexhead has the identical profile with a 4mm longer clutch spline... but the rear end is too long with flutes that keep you from machining it to fit. So close...