TQ HPR60 Drive Unit Set. The HPR60 is the smallest lightest and quietest e-bike drive unit in its class.It was developed to offer an optimal power-to-weight ratio and maximum efficiency instead of just maximum power.The result is a natural unobtrusive riding experience that gives the rider full control. The HPR60 provides intelligent and measured support – for an active riding experience that supports just enough so that you are still riding yourself and not being shuttled by the motor.