Does it bolt up without an adapter
No. You have two choices, machine the forks or machine the calipers so that they centre over the disc (the bolting centres are OK).
I went some distance down this path and decided that I was not comfortable with machining either the fork legs or the calipers and I intended to make an adaptor to fit the 4-spots I bought.
Then I went a different way and am in the process of fitting a K100 front end to my R65 - although my early K-bike front end came fitted with the later Brembo 2-spot calipers (F09s?) the 4-Spots will bolt straight up unmodified, which sort of solves the problem - if in fact I can be bothered fitting them as the twin 2-spots provide all the braking you would ever want. It will come down to which off my collection of master cylinders is able to be rebuilt at the lowest cost - if 13mm then the 2-spots get the gig, the 13mm master cylinder needs a lot of work I will bore it out to take a 15 or 16mm piston and use the 4-spots.
