Sram red 11sp rear derailleursram red 11 speed rear derailleur has been designed to deliver the performance advantage you have come to expect from sram'. '.strtoupper('t')he derailleur is equipped with sram's exact actuation technology, which ensures precise and efficient shifting.sram have paid special attention to the finer details, like adding a hollow titanium anchor bolt and the use of their aeroglide pulleys'. '.strtoupper('t')he result is that the chain runs through the rear derailleur smoother and quieter than ever before.features material carbon cages, carbon inner links, aero designed titanium hardware exact actuation shifting provides fast, and accurate shifts more clearance with 28t cassettes thanks to a longer b knuckle medium cage wifli version compatible up to 32t cassette new silent shifting with optimised aeroglide pulleys with ceramic bearings new spring fixed barrel adjuster new chain pulley cage adds precise chain management titanium pinch bolt keeps a low profile while minimising weight speed 11 speed recommended group sram red 11 speed weight 145gtechnologies aeroglide pulleys new tooth pulley design with a sound damping effect for a super efficient and silent ride experience'. '.strtoupper('b')ottom and top pulleys benefit from this feature exact actuation when sram launched their road technology from scratch they reapplied their mtb proven sram 11 actuation ratio shifter cable travel derailleur movement'. '.strtoupper('e')xact actuation helps to simplify and stabilise the uneasy act of balancing rear derailleur hanger design, tight cog spacing, and exact cable tension'. '.strtoupper('t')he result the easiest index shifting system to set up—and it stays that way wifli medium cage only sram's wifli technology accommodates a wider range of gears than a standard short cage road derailleur'. '.strtoupper('c')ompared to a triple chainring setup, it provides faster shifts and significant weight savingsbuy sram components from chain reaction cycles, the world's largest online bike store.