Torque Anchoring

What you can expect to find on this page

The torque that occurs when driving with a SPEEDHUB must be absorbed using a support on the frame. Here we present the different variants of torque supports within our modular system.

Torque explained

With all gear hubs the axle tries to rotate whilst cycling. When cycling in a reduction gear, the axle attempts to rotate backwards. When cycling in an increasing gear, the axle attempts to rotate forwards. The force with which the axle tries to turn is refered to as torque. The amount of torque depends upon the force applied on the pedals and the gear selected. This torque must be anchored by some means to the frame in order to create forward drive.

On the simple three-speed hubs a flat sided axle is sufficient to secure the torque within the dropout. On a high performance internal gear hub like the Rohloff SPEEDHUB 500/14 the method of anchoring the torque must be considerably more stable due to the wide range of gear ratios.

The amount of torque produced is shown in the following table:

Backwards torque Rotation see picture below or next page, pictures 1, 2 and 3

When the rider applies 20kg onto the pedal, he produces a crank torque of 34Nm. In gear #8 this results in 6Nm torque on the torque arm (18% of crank torque). With the same crank torque of 34Nm in gear #1 this results in 33Nm torque on the torque arm (98% of crank torque). Gear #11 is the direct drive (1:1) the torque on the torque arm is always Zero.


Tritt der Fahrer mit 20 kg auf das Pedal, so erzeugt er ein Kurbeldrehmoment von 34 Nm. In Gang 8 beträgt das Stützmoment 18% des Kurbeldrehmomentes, also 6 Nm. Bei gleicher Pedallast und damit gleichem Kurbeldrehmoment von 34 Nm wächst das Stützmoment im ersten Gang auf 98%, also auf 33 Nm. Der 11. Gang ist der direkte Gang (1:1). Das Stützmoment ist gleich Null.

Rohloff SPEEDHUB 500/14 CC OEM mounted in a frame with adjustable Rohloff OEM dropouts

Depending on the type of frame one of three options can be used to secure the torque:
1) Standard axleplate with long torque arm
2) OEM axleplate
3) OEM2 axleplate
All three anchoring options ensure the axleplate is secured to the frame in two positions to prevents the axle from rotating. The first point A is the axle peg that is secured to the left side dropout. This is the same for all three options. The difference between the three options is point B. The hole pattern on the axleplates allow for individual adjustment of the gear mechs in steps of 30°, so that nearly every frame type can receive an optimum cable routing.

The long torque arm is bolted behind the axleplate. The narrow end B is secured to the frame by means of a clamp or a quick release block. The axle is prevented from turning through these two points. When removing the wheel, the torque arm must first be released from the frame at the narrow end B.

The mounting of hubs with an OEM axle plate is only possible on frames fitted with Rohloff OEM dropouts. The OEM axleplate sits in the dropout slot of the OEM dropout. The axle peg A slides in first followed by the support block B into the same slot. The dropout itself prevents these two parts from turning. When removing the wheel, the two parts fall out the dropout together once the axle has been loosened.

Mounting the SPEEDHUB 500/14 using an OEM2 axleplate is only permitted on frames with international standard (IS1999) disc brake mounts. The OEM2 axleplate sits with its axle peg A in the dropout. The axleplate seat B secures itself around the supporting peg of the Rohloff SPEEDBONE or MonkeyBone (when mounted on a bike with disc brakes) or around the support bolt fastened through the lower brake caliper mounting hole (when mounted on a bike with rim brakes). When removing the wheel, the axleplate falls away from the support bolt/Rohloff SPEEDBONE / MonkeyBone and out of the dropout once the axle is loosened..

Long torque arm

All Rohloff SPEEDHUB 500/14 versions not carrying the codes OEM or OEM2 come included with the long torque arm for supporting the torque. This must be mounted to the axle plate.

A Threaded bush
B Washer
C Mounting bolt
D Axle plate (CC or TS)
E Long torque arm

Push the threaded bushes through the torque arm from behind. Place a washer over each of the bushes and then the axle plate over these washers (pictures 1 and 2 show the TS version). Secure the two parts together with the mounting bolts. (M8x0.75 - 5mm allen key, tightening torque: 7Nm/61in.lbs.).

E Long torque arm
F Locating fork
G Securing pin with circlip
H Circlip

On the CC versions, the locating fork must also be attached to the torque arm. Place the forked end over the torque arm, push the securing pin through the two parts and secure the other end in place with the circlip. TS Versions must have a torque arm clamp mounted instead of the locating fork.


Make sure that both circlips sit correctly onto the securing pin.

OEM2 mounting

OEM2 mounting with a support bolt

The support bolt assembly for OEM2 mounting consists of a bolt (M6x16), a washer and a locknut. It is secured through the disc brake mounting  hole of the dropout from the inside (tightening torque: 8Nm/71in.lbs.).


Mounted support bolt, view from inside the frame.

Mounted support bolt, view from outside the Frame.

OEM2 mouting using a SPEEDBONE

OEM2 mouting using a Rohloff SPEEDBONE

The Rohloff SPEEDBONE is mounted from the outer side of the frame and secured through the disc brake mounts into the brake caliper (paying attention to the brake manufacturers tightening torques). The original caliper securing bolts will be too short to mount through the Rohloff SPEEDBONE and should, therefore, be replaced by the long Rohloff SPEEDBONE securing bolts.

Rohloff SPEEDBONE (Art. #8550) with securing bolts.

Mounted Rohloff SPEEDBONE, view from inside the frame.

Mounted Rohloff SPEEDBONE, view from outside the Frame.

OEM2 Mounting using a MonkeyBone

The MonkeyBone is secured to the inside of the disc-brake mounts on the dropout. The disc-brake caliper itself is then bolted down onto the MonkeyBone from above (uphold torque values from brake manufacturer). Not compatible with frames with disc brake caliper mounts positioned on the chainstays!

Monkey Bone Montage

Monkey Bone IS-PM Adapter for O.L.D. 135/142/148/170/177mm
(160mm = Art. #8553) (180mm = Art. #8554)
Monkey Bone IS-PM Adapter for Fatbike O.L.D. 190/197mm
(160mm = Art. #8553-10) (180mm = Art. #8554-10)

The Monkey Bone offers a simple method of anchoring the axle of the Rohloff SPEEDHUB 500/14 to a frame through the disc brake mount. In order to use the Monkey Bone, your SPEEDHUB 500/14 will need an OEM2 axleplate, your frame must have an International Standard disc brake interface, and your disc brake caliper must have a Postmount interface. The Monkey Bone is not compatible with IS direct-mount disc brake calipers or frames with Postmount disc brake interface.

Required Tools

  • 5mm Allen wrench
  • Torque wrench
  • T20 Torx wrench

Required Parts

  • Frame with IS51 disc caliper mount interface
  • Disc brake caliper with Postmount interface
  • Rohloff SPEEDHUB 500/15 with OEM2 axleplate
  • Monkey Bone/Monkey Bone-10
  • 2x M6x16mm bolts (sold separately; typically included with disc brake caliper)
  • 2x M6x18-20mm bolts (sold separately; typically included with disc brake caliper)
  • 2x M6x30mm bolts (included with Art. #8553-10 and Art. #8554-10)

Installation Instructions

  1. Ensure that you have the Monkey Bone that is appropriate for your disc rotor diameter (160mm or 180mm; 203mm rotors can be used with 180mm Monkey Bone and spacers (sold separately).
  2. Attach the Monkey Bone to the frame using two M6x18-20 bolts.  Ensure that slot for OEM2 axleplate faces the dropout. Tighten bolts to a torque of 6Nm/51 in-lbs.
  3. Connect disc brake caliper to Monkey Bone using two M6x16 bolts (for Fatbike M6 x 30mm). Leave bolts loose enough that caliper can slide side to side.
  4. Install wheel into dropout taking care to align slot in end of OEM2 axleplate with cutout in Monkey Bone and disc rotor between brake pads.
  5. Check position of EX shift arm with OEM2 axleplate engaged with slot in Monkey Bone; reposition axleplate as needed for desired cable routing using T20 Torx wrench (see Rohloff Owners Manual). Tighten axleplate screws to a torque of 3Nm/25 in-lbs.
  6. Fully seat axle in dropout before tightening quickrelease lever or axle nuts.  Threaded axle nut torque: 30 Nm/310 in-lbs; Pitlock or bolt-on skewer torque: 7 Nm/60 in-lbs.
  7. Follow brake manufacturer’s recommendation for setting brake caliper position. Tighten brake caliper bolts to a torque of 6Nm/51 in-lbs.

Permissible with CC/TS axle

Non-permissible with CC/TS axle

[Übersetzung nötig] Hinweis

Kombinationen für Bremsscheibe 200mm/203mm:

Bremsscheibe 200mm: Monkeybone 180 mit Adapter PM - PM+20
Bremsscheibe 203mm: Monkeybone 180 mit Adapter PM - PM+23

Alle Adapter müssen für Verwendung am Hinterrad dieses Rahmens geeignet sein.


[Translate to en:] Bei Montage an Steckachsrahmen mit A12-OEM2 Achsplatte muß die Position des Abstützpunktes nicht beachtet werden.


Use of the Monkey Bone (both CC & TS Axles) with certain frames could result in the wheel being levered out of the dropout while pedaling due to the forces exerted by the Rohloff SPEEDHUB 500/14 onto the frame. The reaction force in the lowest gears can lever the axle down and out of the dropout slot if the anchoring point of the OEM2 axleplate is located in front of a parallel line through the dropout slot. The Monkey Bone and OEM2 axleplate combination is not permissible for use on such Frames.

Use of the Monkey Bone and OEM2 axle plate is entirely at the user’s own risk. The forces applied to the disc brake mount by the Rohloff SPEEDHUB 500/14 can damage some Frames.  Please contact your frame manufacturer to determine whether this setup is appropriate for your frame and whether it affects your frame warranty.

PM Bone Montage

PM Bone (Art.#8555)
PM axleplate (CC PM =Art.#8225), A12 PM (Art.#8558)

The Rohloff PM Axleplate in combination with the PM Bone offers an alternative method of anchoring the hub torque to frames with a 135mm, 142mm, 170mm or 177mm spacing. The PM Axleplate/PM Bone combination is recommended when mounting a SPEEDHUB in all frames with an integrated Postmount direct calliper mount. The threaded holes of the direct calliper mount will be used to secure the PM Bone.

Three different mounting options are available:

  1. Mounting to frames where the (PM) direct brake caliper mount is on the seat-stay.
  2. Mounting to frames where the (PM) direct brake caliper mount is  on the chain-stay.
  3. Mounting on frames where an International Standard (IS) brake caliper mount is  on the Chainstay.

Possible combinations:

PMdirect  140mm = Not compatible!

PM direct 160mm = 180mm rotor required!
PM direct 180mm = 203mm rotor required! 

PM direct  203mm = Not compatible!


The PM Bone (Art.#8555) must be mounted under directly under the disc brake calliper. This acts an adapter and thus ist use will require the a larger brake rotor:

PM Bone - Mounting preconditions

The axle area of the Rohloff PM Axleplate must lie flush against the dropout material.

The axleplate may under no circumstances collide with weld-beads or proud standing frame tubes.

Safe use of the PM Bone/PM axleplate is only possible if these two preconditions are satisfied.


The various different standards & production tolerances of the Postmount caliper mount will result in the PM Bone loacting peg resting at different heights within the PM axleplate fork.

  • Frames using a 160mm direct postmount must result in a gap of min. 0.3mm between the plate & bone (use spacers if necessary).
  • Frames using a 180mm direct postmount must result in a gap of max. 7mm between the plate and bone.

Get in touch with Rohloff service should issues arise when mounting the two PM components.


Neither the PM Bone nor PM axleplate are authorized or tested for tandem use!

Mounting to frames where the PM direct brake caliper is located on the seat-stay.

Mounting to frames where the PM direct brake caliper is located on the chain-stay.


Use of the PM Bone/PM axleplate is only permitted in dropouts where the PM Bone anchoring point falls behind an imaginary line drawn through the dropout slot itself. The correct location of the anchoring point is vital to ensure the axle cannot lever itself out of the dropout and thus to avoid potential accidents and injuries!

Mounting on frames with an IS brake caliper mount located on the Chainstay:

An IS/PM adapter is secured to the IS calliper mount as usual. The Rohloff PM Bone (Art.#8555) is then mounted to this and the calliper then bolted to the IS/PM adapter through the PM Bone.


Possible combinations:
IS frame  160mm + IS/PM Adapter 160mm + PM Bone = 180mm rotor required
IS frame  180mm + IS/PM Adapter 180mm + PM Bone = 203mm rotor required

Table: Amount of torque

Torque in percent of crank torque with a 42/16 sprocket ratio. The rows "forward" and "backward" explain in which direction the torque rotates.

Gear 1 2 3 4 5 6 7 8 9 10 11 12 13 14
% 98 82 68 55 44 34 25 18 11 5 0 5 9 12