The world's fastest Pulley Wheel system just got faster. The OSPW Aero has a lifetime warranty and is wind tunnel tested to have 40% less friction compared to a standard shifter, making it perfect for single starts or triathlons.

The system features a 13-tooth upper pulley wheel and a 19-tooth lower pulley wheel, as well as coated CeramicSpeed bearings to provide the absolute best optimization of the rear derailleur.

Compatible up to a 32-tooth cassette