Disc brake advice-adapters, and WTB

[marciero]

Advice needed-I am trying to avoid trial and error by working out the adapter situation on a new drop-bar all road (with 6700 shifters). I have a flat mount fork and IS rear, and will go with mechanical (or maaybee cable-actuated hydro) and 160 rotors. So I will just get the flat mount brake (am thinking Spyre since I've used those on our tandem) for the front. The fork manufacturer says flat mounts often come with an adapter that is reversible for 140 or 160 rotors. So that seems straightforward. For the rear, I have seen the IS-to-post mount adapters for different rotor sizes, and according to LBS I would get the post mount version of the brake and use appropriate adapter. I have seen these adapters advertised for different rotor sizes, but is that standardized or would that also depend on the frame? Any other advice? Thanks. Here is the rear of the frame. WTB for brakes to suit.

[sales guy]

They offer adaptors in the normal sizes for the rotors you want. So just pick which rotor size and get that adaptor. The adaptor will have the rotor size listed on it.

Normal rotor size is 160mm front and rear. Some frames, depending on the tubing shape, mount position it might be a 140mm rear. For this frame, given the mount is on the seatstay and not the inside of the chainstay, you can use a 160mm rear.

So order up a post mount front and rear caliper and a 160mm adaptor. 160mm rotors and you'll be fine.

[marciero]

They offer adaptors in the normal sizes for the rotors you want. So just pick which rotor size and get that adaptor. The adaptor will have the rotor size listed on it.

Normal rotor size is 160mm front and rear. Some frames, depending on the tubing shape, mount position it might be a 140mm rear. For this frame, given the mount is on the seatstay and not the inside of the chainstay, you can use a 160mm rear.

So order up a post mount front and rear caliper and a 160mm adaptor. 160mm rotors and you'll be fine.

Thanks. But do you mean flat mount front since the fork is flat mount?

[sales guy]

Thanks. But do you mean flat mount front since the fork is flat mount?

Oops. Typing to fast there. If your fork is flat mount, order that and a 160mm mount. Looks like a large shim(a chunk of aluminum basically).

For the rear, order a ISO to post mount adaptor for 160mm rotors.

[marciero]

Perfect. Sounds simple enough.

[sales guy]

Perfect. Sounds simple enough.


It is. There are tons of helper out there too. Bikehugger has a great post from Mark V about brakes and adaptors.

Front:
flat mount caliper
160mm shim
160mm rotor

Rear:
ISO post mount caliper
160mm adaptor
160mm rotor

And no, it doesn't matter who's adaptor it is. Some fit a little better than others. But if you want to make sure just get the same brand as the brakes to make sure and make your life easier.