These pulleys will just not stop spinning! Don't take our word for it, just listen to our friend and badass racer Allison Linnell, doing a full spindown on video right here . The name of these pulleys came from the fact that Instagram videos were limited to 15 seconds. There is no way to show how well they spin in 15 seconds. Since then Instagram has lifted the long video ban and Kogel is looking to rename this amazing product. Send us your suggestions! - road use only - compatible with 10 and 11 speed Shimano derailleurs - compatible with Campagnolo 11 speed - compatible with sram Red22 and Etap after a change of dust covers. Just select it from the dropdown menu and we will take care.