Tacx T4095 Gear Rollers Ceramic - Sram Sram Race for Force, Rival and Red Smooth running jockey wheels - The Tacx jockey wheels are manufactured from a resin composite that is very resistant to wear and equipped with quality precision bearings. - Thanks to the closed bearings they will not get stuck, show play or squeak. - For extreme circumstances, such as mountain biking or cyclo-cross, Tacx have jockey wheels equipped with stainless steel bearings. - Top of the bill are the wheels with ceramic bearings. They run extremely smoothly for the highest performance.