An ATV endless track conversion using sprocket rings fit over each of the tires of the rear wheels which are inflated into a tight driving connection. A swing arm extension is pivoted to the ATV swing arm and has its own spring-shock absorber suspensio n in addition to the existing ATV spring-shock absorber. A return idler wheel set is mounted at the rear of the swing arm extension as well as two track band shaping wheel sets which engag e track band upper and lower segments forward of the idler return wheel set to maintain t he track band tension and footprint without substantial friction losses.
