 In a typical application, power is transmitted to a "drive sprocket" (or drive wheel), which drives the track around its loop.On the opposite end of the vehicle, there is an "idler wheel", which provides a pulley wheel of sorts.On some applications, the drive sprocket and idler wheel carry some of the weight of the vehicle, for the purposes of this description, we will assume the drive sprocket and idler wheel are not weight-bearing units, and the drive sprocket is on the front (see M4 Sherman for an example).