It seems that every cool aftermarket handlebar out there is for 7/8″ bikes. BMW has a slightly smaller handlebar measured at 22mm diameter.
PURISTS BEWARE (I’ve been criticized for the following procedure before).
All it takes to solve the issue is a Dremel and some grinding bits.
Also, please note that i have already ground down the handlebar mount clamps to fit nicely over the 7/8 bars.

Tools for the job.