Brakes question

pedalbasher

I have bought a titanium frameset which accepts post-mount disc brakes (front and rear).

I have also bought a replacement front fork (because I wanted thru axle rather than QR) and the new fork is set up for flat-mount disc.

I've also bought a full Ultegra hydro groupset which includes flat-mount calipers.

Am I right in thinking I can run an Ultegra flat-mount brake at the front, and I'd have to buy a post-mount caliper such as the Shimano BR-RS785 caliper at the rear?

I appreciate that flat-mount is becoming the norm, but my OCD means I would prefer to run the same brakes front and rear. Can I therefore buy an adaptor to use a post-mount caliper at the front, and then run BR-RS785s both front and rear? Then I could just sell the Ultegra calipers as a set. Is this a silly idea?

Thanks

dj58

Or do it the other way round, flat mount caliper to post mount frame adaptor.
https://www.assolutions.ca/flat-mount-c ... ter-guide/

cycleclinic

Run flat front and post rear. Adapters like those listed if not made properly could brake rubbing. It would be difficult to face that adatper.

pedalbasher

Thanks both.

I think i'd prefer to run post front and rear rather than flat front and post rear with mis-matching calipers. I dont mind the post mount look and im sure it will add to the retro appeal of the bike in years to come with no performance compromise

Having said that, those ASS adapters look good! @thecycleclinic I didnt understand your msg properly - are you saying the ASS adapters linked by @DJ58 cause rubbing? What do you mean when you say "it would be difficult to face that adapter"?

Thanks again.

Alejandrosdog

pedalbasher wrote:

Thanks both.

I think i'd prefer to run post front and rear rather than flat front and post rear with mis-matching calipers. I dont mind the post mount look and im sure it will add to the retro appeal of the bike in years to come with no performance compromise

Having said that, those ASS adapters look good! @thecycleclinic I didnt understand your msg properly - are you saying the ASS adapters linked by @DJ58 cause rubbing? What do you mean when you say "it would be difficult to face that adapter"?

Thanks again.

Cycleclinic was referring to the process of grinding a bike mount to ensure absolutely flat and parallel surfaces on which to mount the brake caliper.

This is sometimes necessary to rectify some manufacturing defects or remove paint or other material that might affect the mount surface.

The procedure is simple but requires an expensive tool (several hundred pounds) .

Facing the mounts can rectify rubbing and sometimes noisy brakes when all else seems not to work. If your local shop has the tool, make sure the enthusiastic saturday boy does not use it.

pedalbasher

Thanks. I think I'm going to give the adaptor a go - frame is high end titanium so hopefully there should be little chance of defects or paint/ other materials on the mounting surface.