CeramicSpeed has launched a new oversized pulley wheel (OSPW) RS derailleur pulley system today. The Danish brand says the OSPW has been 'lifted into the future' receiving innovative new tech features as well as a 'distinctly modern and angular design'. It will be compatible with Shimano and Sram road groupsets. It does also share some tech features with the OSPW X for the Sram Transmission MTB unit that was launched last Autumn.
The original OSPW (oversized pulley wheel system was launched back in 2015 and the brand unveiled its aero OSPW in June last year. OSPW systems have become a popular, if expensive way to improve drivetrain efficiency thanks to the larger derailleur pulley wheels themselves and ceramic bearings.
CeramicSpeed says the updated design of the OSPW RS allows it to blend seamlessly into the contemporary design trends of modern bikes and groupsets. The brand claims there are also now more customisation options available such as multiple logo and colour options as well as two different types of lower pulley which we unpack in the tech info below.
ADR and Alpha Disc features
Visually a key change to the OSPW RS is the solid lower pulley wheel or Alpha Disc as the brand has named it. This feature was first introduced on the OSPW X for Sram MTB drivetrains. CeramicSpeed says the cage of the derailleur has also been reinforced to provide more strength and durability and the OSPW will be available with small or large team edition logos and either five spoke pulley wheels in five colour options or the solid Alpha Disc wheel.
The Alpha Disc features a two-piece construction. A separate narrow wide tooth profile is made from a composite material which the brand says prolongs wear protection and reduces noise. The second piece is the solid aluminium disc that is said to eliminate the risk of objects or debris being stuck between the spokes of the pulley wheel while adding strength and stiffness.
CeramicSpeed has also developed what they call the ADR or Active Debris Remover feature. The brand says this is a patent pending feature that makes it virtually impossible for debris to enter the OSPW RS bearings. The ADR itself is a new dust cover which is anchored in a groove around the pulley wheel, enclosing the bearing itself. A 'bladed groove structure' surrounds the dust cover which the brand claims dynamically extracts debris from the pulley wheel whilst it's rotating.
CeramicSpeed says this feature has been developed with R&D departments and pro-off-road teams. It appears the Team Tormans cyclocross team were instrumental in developing the ADR and solid pulley wheel features.
Kobe Siemons, former head mechanic of the Tormans CX team (now with Soudal QuickStep) said:
"To optimize the current version of the OSPW, we started to think of solutions to let it perform even better in heavy mud. We gave feedback to the CeramicSpeed R&D Department – and asked them to work on a full disc design to avoid mud sticking to the pulley wheels and to perform better in heavier conditions."
It seems performance in muddier, tougher conditions was a factor in the new unit's development and the Alpha Disc sounds like it could be an option for gravel riders or cyclocross racers.
Siemons said "We used the first version of the full pulleys for one season, then we got an updated pulley wheel with a bigger bearing and caps with the “ADR function” to avoid grass and mud turning in the bearing and mud sticking to the pulley wheel. Till now we are still using these same prototype pulleys in the heaviest circumstances and “grass races”, because it makes a huge difference for our riders to ride their bikes without a hopping gear or bad-turning drivetrain".
We will add pricing info on the OSPW RS when we receive it.
