I hope, that someone can help with that.can`t find in forums.
so, need to upgade rear breaks for `03-04 636. I want to use original break disc, but want to change calipper-with 4 pistons from front.and want to put it in place in original calipper!?how to do that?
OR...
leave original calipper and add front calipper for hand break.
and one more question: have someone tried to use thumb break for rear break??

 

today will try thumb break, but I think that it will be too weak