also leaves the question.....WHY?
because I want to? they were universally regarded as a crap brake that overheated at the drop of a hat
by the majority, but properley maintained were adequateand were a right pain in the arse to maintain (wheel out etc to change pads and allow at least an hour for the job)
given yes, they a re a pain when compared with fork mounted callipers that only require two bolts.... an hour, no way. wheel off and cover open in an extra 10 ...15 max minutes
this isn't just idle speculation, i used to work in a secondhand bike shop in the 80s and i don't think i ever heard the mechanic swear that long or loud at any other bike, and he was good at swearing too.
another way of looking at it is.....how many bikes are still using this system?
this appeals to me, theyre different
incidentally they ripped the idea off Lambretta who hold the record for the first disc brake fitted to a two wheeled vehicle (1962 i think - TV200/GT200) lambretta had a lot less problems as they were dealing with much lower speeds/weights/braking forces