These pulleys will just not stop spinning! Running on our full ceramic bearings without any lubrication, these wheels are guaranteed to spin at least 15 seconds. This was the time limit set for Instagram videos when we released our first set of full ceramic pulleys in 2015. This set will compliment your Shimano 11 speed and Campagnolo 12 speed derailleurs. They also work well for Sram Etap 11 and 12 speed.