The PM Bone allows mounting of a Rohloff Speedhub on frames (135mm, 142mm, 170mm, 177mm) with a direct post mount brake mount (for 160mm or 180mm discs). In order to derive the hogging moment of the hub over the PM Bone into the frame, a PM axle plate must be used.
The PM Bone is mounted between the frame and brake caliper and thus acts like a + 20mm adapter, which requires the use of each 20mm larger disc.
Examples of possible combinations:
- Frames with PM direct support for 160mm disc = PM Bone with 180mm 4-hole Rohloff brake disc.
- Frames with PM direct support for 180mm disc = PM Bone with 203mm 4-hole Rohloff brake disc.
- Frames with PM direct support for 140mm or 203mm disc = not compatible!