A suspension system is provided for a vehicle track assembly having a lower front idler wheel, a lower rear idler wheel, an upper drive wheel, a support link, a plurality of lower support wheels arranged between the idler wheels and mounted on the support link, and an endless belt mounted around the wheels. The front and rear idler wheels are separated by a length L. An upper belt plane is tangent to one of the idler wheels and the drive wheel and a lower belt plane is tangent to the front idler wheel and the rear idler wheel. The vehicle center of gravity is located a distance H above the lower belt plane. A suspension member pivots about a fixed pivot axis. The components of suspension system are sized and arranged to prevent the vehicle from diving or squatting.