 The "Independent Drivetrain" (or "IDrive") is a four-bar suspension system for bicycle crank assemblies, the rear wheel itself is suspended as single pivot suspension.It was developed by mountain bike suspension designer Jim Busby Jr. and was a direct result of the limitations encountered with the GT LTS (GT Bicycles' "Links Tuned Suspension") four-bar linkage design used by GT Bicycles from 1993 to 1998.The IDrive attempts to maximize the efficiency of the transmission of energy from the rider to the rear wheel.