Tensioner Arm
EXPLODED VIEWS
Supre Drive Tensioner Arm
1. Tensioner arm
1.1 Tensioner arm pivot bearing
1.2 Retaining ring
1.3 Dust shield
1.4 Mounting spacer
1.5 Cable retention pin
2. Cable clamp bolt
2.1 Cable clamp washer
3. Tensioner pulley
3.1 Pulley spacers
3.2 Bearing
3.3 Pulley bolt
INSTALLATION
Installing the tensioner arm
- The Supre Tensioner Arm is only compatible with Supre-Drive-specific frames and T47 inboard bottom brackets.
- With the cranks and drive-side bottom bracket cup removed, clean the tensioner arm mounting surface (outer face at the end of the BB shell), and apply a thin layer of grease to it.
- Push the tensioner arm with the mounting ring (thin, plastic ring) onto the bottom bracket shell.
- Ensure that there's waterproof grease on the visible part of tensioner arm pivot bearing. Then, install the dust shield (which shields this bearing) and install the drive side bottom bracket cup to secure the tensioner arm in place.
- Rotate the tensioner arm around ensuring it rotates freely.
Installing the cable
- The Supre Cartridge, Supre Derailleur, and chain need to be installed before continuing with this step.
- Route the cable, from front to back, through the gap between the cable retention pin and the cable channel. Then from back to front through both the cable channels in the ribs of the tensioner arm. Finally wrap the cable down and around the tensioner arm body and under the cable clamp bolt.
- Make sure the cable is on the correct side of the cable clamp bolt and lying in the v-groove under the bolt
- With your rear wheel installed and the drivetrain in the highest gear, rotate the tensioner arm forward as far as possible, taking up all of the slack in the chain.
- Pull down on the tensioner cable to hold the tensioner arm in position with no slack in the chain. While pulling down with one hand, mark the cable with a permanent marker just below the cable clamp bolt.
- To let the tensioner arm rotate freely, remove the chain from the idler pulley or tensioner pulley, or remove the rear wheel. Pull the cable until the mark is 10mm down from the cable clamp bolt. Torque the cable clamp bolt to 3 Nm (fairly tight).
- It's important that the cable clamp bolt is fastened to the correct torque. Otherwise, it risks slipping, causing a loss of chain tension at least in the highest gear.
- Cut the cable around 2cm from the cable clamp bolt and install a ferrule.
SETUP/ADJUSTMENT
Adjust the cable tension
- If you shifting performance is poor in the highest or lowest gear, it may be necessary to check that your cable tension isn't incorrect from a mistake in assembly.
- Small cable adjustments will make a big difference in chain tension. Keep cable adjustments <5mm.
- If the chain is slack in the highest gear, check that the cable tension is not too low and pull a small amount of cable.
- If the derailleur struggles to shift out of the lowest gear, check that the cable tension is not too high and release a small amount of cable.
- Un-do the cable clamp bolt. Pull or release the appropriate length of cable. Re-fasten the cable clamp bolt.
- It's important that the cable clamp bolt is fastened to the correct torque. Otherwise, it risks slipping, causing a loss of chain tension at least in the highest gear.
Locking the tensioner arm
- Rotate the tensioner arm back roughly a quarter of a rotation.
- With your other hand reach under the tensioner arm and pull down on the spring hook, release the tensioner arm slowly while holding the spring so that the spring slides over the barrel bolt.
- Locking the tensioner arm is useful when removing the rear wheel or working on the drivetrain.
- To release, rotate the tensioner arm back slightly until you hear the spring "click" off of the pin bolt.
MAINTENANCE
Replacing the tensioner pulley
- Remove the tensioner pulley bolt.
- Replace the pulley or bearing as needed, and re-install the pulley assembly.
- A light light threadlocker should be used when re-installing the derailleur pulley bolt.
- The inner and outer pulley spacers are identical and can be installed on either side of the pulley. Also, the pulleys of the Supre Drive are symetric and can be installed in both orientations.
Replacing the tensioner arm bearing
- With the crankset and drive side bottom bracket removed, un-do the cable clamp bolt and un-thread the cable.
- Pull the tensioner arm off of the bottom bracket shell.
- Pull the tensioner arm evenly all around the entire circumference. Make sure it is pulled off straight to avoid damage.
- Remove the dust shield and the retaining ring. The retaining ring can be removed by using a small flat head screwdriver and carefully prying the end of the retaining ring out.
- Use an oversized headset cup removal tool (for example, Park Tool RT-2) to carefully knock the bearing out of the tensioner arm.
- A heat gun can be used to carefully heat up the tensioner arm around the bearing to make it easier to knock out.
- Lightly grease the new bearing and press it into the clean tensioner arm.
- The bearing can be pressed using an arbor press, a bearing press, or a vise. Be careful to press the bearing in straight.
- Re-install the tensioner arm.