Using a 7-speed rear cassette combined with a triple front derailleur, the EGS Synchro Shift system provides the rider with 11 speeds to choose from. With the synchro shift, it is possible to select and synchronise all the effective gears by means of a barrel inside the grip. The barrel is the controlling part of the system. It eliminates mechanically inefficient gear combinations and ratio-redundant gear combinations, offering only the most effective gears to the user. The gear combinations are staged progressively and naturally and are selected by the simple rotation of one grip. This product is designed to chose the best sprocket and chainwheel. It is a system that provides one shifter controlling two derailleurs simultaneously. It uses all relevant gears that produce progressive covered distances and a continually straight chain line. Source: Edited text from EGS Syncho Shift website