CeramicSpeed releases the only 17-tooth pulley wheel system on the market, a real advancement for the cycling world. Developed and produced in Denmark, the new CeramicSpeed Oversized Pulley Wheel System starts the energy savings at 2.4 watts thanks to the 60 % lower friction achieved, compared to commonly used bearings on the market. The performance of the system is given by the size of the pulleys, the CeramicSpeed bearing quality and the design of the cage, all developed by CeramicSpeed and tested and proven by third party independent test lab Friction Facts. Tests have been made at 95 RPM in 53/12 gear, using a Reactive Torque Pulley Tester (RTPT). BIGGER - proven to be better!