I've spent about 30 minutes searching the threads in this forum for the answer to this:

Does the RacingBrake rear brake kit for the FD fit with stock wheels?

I've seen in the past some posts indicating that some modification to the calipers may be necessary, but can't seem to find them now. The thread on the RacingBrake kit is quite long...

If I can get an answer here, the next person with this question will find this thread useful as well.

 

afgmoto1978 tells me that not only does the rear kit not fit under stock wheels, it doesn't fit under some 17" wheels.

 

That is correct. I've had problems fitting 17" RPF1's over the RB rear BBK.