I am lurking around building an all-year/all-weather bike, based on the FR-603 frame.

It has room for wider tyres and mudguard studs, compared to a “pure” racing frame.

A Shimano 105 group-set with disk brakes seems to just have been released and perfectly fits my requirement. However as always, their seems to be a (small) fly in the soup.

The 105 group-set comes with flat-mounted brake-calipers (BR-RS505). Looking at the FR-603 frame, it has “studs” for the brake calipers, with at least to me are for post-mounted brake-calipers.

I asked one of the Chinese suppliers of FR-603 about this and he clams that the BR-RS505 would fit, so now I am slightly confused.

So the questions are


A. Is the FR-603 frame for flat- or postmounted brake calipers ?

B. Can the BR-RS505 brake calipers be used on the FR-603 frame with some from of adaptor ?

C. Can’t any post-mounted brake caliper (from MTB) not be used, if the FR-603 frame is for post-mount ?

D. And is such an adapoter is used, will the "move" the brake-caliber away so a bigger rotor-disc is needed ?

E.Anything else I should know about the FR-603 frame, please come forward...


English is not my native language, so if something is unclear I do apologize.


BR

Thomas