When absoluteBLACK first released the HOLLOWcage Oversized Derailleur Pulley Cage for Shimano, we have to admit, we were skeptics. Thankfully, throwing the cage on our rigs has transformed our view of expensive drivetrain parts and brought peace of mind to our rides. The pulley works its magic to quiet down our drivetrain which significantly reduces friction and produces marginal gains. The new pulley also looks slick too with its oversized wheel reducing drag and increasing sight value.