Designed exclusively for 26" , 27.5", and 700c bikes with disc brakes- Wide clearance posts space rack away from disc brake caliper- Fits frames with threaded rack mounting holes on the dropouts- Tubular 6061 aluminum with QuickTrack plate which accepts all MTX2.0 series trunk bags- Integrated spring clip is convenient for securing lighter weight cargo- Accepts all MTX trunk bags- 57lbs weight capacity- Not compatible with frames with asymmetrical chainstays