Flat,Post,I.S.

The "BrakeMount" field tells you what system the frame has to allow installation of brakes. There are three systems with disk brakes, and two main systems with rim brakes.

1. Disk Brakes
    To mount the caliper onto the frame, there are three standards:
    
     Post mount
     Flat mount
     I.S. (International Standard)

   In general, each mounting system can take either mechanical or hydraulic calipers for that type. Eg: If you want hydraulic calipers, and your frame is post mount, then you need Post Mount hydraulic calipers. You can''t use flat mount calipers unless you had an adapter.
     See Introduction to Mounting.

2. Rim Brakes
    For rim brakes, the three main systems are:
     Above the fork (road bikes, original 10 speeds)
     Cantilever (touring bikes, starting in 1986, also Mtn bikes)
     Cross pull (V Brakes) starting in 1995