PM Bone (PM-PM Adapter)
The PM Bone enables a SPEEDHUB, fitted with a PM axleplate, to anchor its output torque to a frame equipped with Postmount direct brake mount. This torque anchoring system can only be used on 135mm, 142mm, 170mm and 177mm spaced frames with a direct mount for 160mm or 180mm brake rotors.
The PM axleplates which grip onto this PM Bone are available for both CC and A12 axle styles:
- Axleplate CC PM = for Rohloff SPEEDHUBs with a hollow quick release axle. These can be pre-fitted to new hubs or purchased separately to convert existing hubs.
- Axleplate A12 PM = for Rohloff SPEEDHUBs with an internally tapped axle for mounting in 12mm thru-axle frames.
These can be pre-fitted to new hubs or purchased separately to convert existing hubs.
The PM Bone Is mounted between the brake caliper and the frame itself. As such, the PM Bone acts as a +20mm adapter and thus will require a 20mm larger brake rotor.
- Frames with a Postmount designed to accept 160mm brake rotors will require a 180mm brake rotor when using the PM Bone.
- Frames with a Postmount designed to accept 180mm brake rotors will require a 203mm brake rotor when using the PM Bone.
- Frames with a Postmount designed to accept 203mm brake rotors are not compatible with the PM Bone.
Important compatibility check!:
As with all SPEEDHUB axleplates, a 40mm diameter flat surface surrounding the axle center is required. Further checks are necessary if used on frames where the brake mount is located on the chainstay. ATTENTION: Regardless of whether the Postmount is positioned on the chainstay or seatstay, the anchoring point of the PM Bone must always be located behind a vertical line through the axle center (on frames with vertical dropout slots). The SPEEDHUB will easily produce enough torque to lever its own axle out of the dropout slot, is this anchoring point is in front of the axle center.
Instructions for mounting the PM Bone ode PM axleplate (pdf)
PM Bone and PM Axleplates:
|PM Bone (28g)||8555|
|Axleplate CC PM (135mm/170mm)||8225|
|Set CC PM (PM Bone + Axleplate CC PM)||8563|
|Axleplate A12 PM (142mm/177mm)||8225|
|Set A12 PM (PM Bone + Axleplate A12 PM)||8564|
Further information over the Rohloff PM-Bone can be found under downloads.