CeramicSpeed Oversized Pulley Wheel System - Limited Giro D'Italia - Shimano Dura-Ace 9100 Standard Bearing

With the advent Shimano Dura-Ace 9100 mechanical and 9150 electronic, the most common rear derailleurs used by pros, it was essential that CeramicSpeed develop a new Oversized Ceramic Pulley Wheel System (OSPWS) for the derailleur. As you can imagine, CeramicSpeed has done everything possible to reduce frictional drag to as close to zero as is possible. They started with pulley size. They determined that the best solution was a 13-tooth upper pulley and a 19-tooth lower. This way, you can install cassettes up to 32-teeth on your rear wheel and still take advantage of these pulleys. The result is a 30% drop in mechanical friction and three to five times longer lifetime than the standard Shimano pulley setup. The pulleys are fabricated out of aluminum and have spokes supporting the teeth rather than solid aluminum, which both reduces weight and reduces muck buildup in dirty conditions. But this isn’t merely about reducing friction. It’s about improving performance everywhere possible. Th