BMW does not make mistakes.
Yeah right!
Telescoping front end on /2s /5s /6s and /7s (not enough trail and will wobble without a steering damper at slow speed) Inferior damping to japanese and even Harley frontend at the time. Also the Earles (leading link) that the telescoping replaced is still the best front end built for hack use.
Front Disc brake, cable operated with master cyl. under tank. (/6 and /7) Honda brakes were much better.
One sided swing arm paralever used on R100 GS (drive shaft only lasted about 30K, but drive shaft in pre-paralever lasted forever)
Speedo driven off tranny and not front wheel. (if you change rear end ratio speedo incorrect)
Akroft Aluminum wheels to mount "tubeless tyres" Least bit of corrosion and they no longer seal at bead, best to use tube.
Non canceling turn signals, some even on same handle bar. (HD canceled and were on both bars in the 60s)
And what about BMW (/2) manual that tells motor oil cap. in Litres, Bevel drive oil cap. in pints, and drive shaft oil cap. in cups. Gas tank cap. is listed in Gallons (both US and Imp) also mentions some liquids in fluid ounces but is that for US or UK fl.oz. (the thing I really dislike about manual is it does not tell bikes weight in stones)