Abstract: This invention relates to a traction assembly for a vehicle which uses an endless traction band and a plurality of wheels for propulsion. More particularly, the traction assembly comprises a sprocket wheel which has a different size and number of sprocket teeth depending on whether the traction kit replaces the front wheels or the rear wheels of the vehicle. The sprocket wheel of the traction kit can also be configured such that its sprocket teeth are laterally offset. The traction kit can also comprise an anti-torque system that prevent physical contact between the traction kit and the vehicle and that can bias the position of the traction kit in order to improve the steering performance. Finally, the traction assembly can comprise a pivotable extension which lengthens the traction assembly and improves its traction capabilities.

Abstract: A drive sprocket for a snowmobile, a drive train using the sprocket, and a method of using the sprocket to drive a track for a snowmobile. The drive sprocket includes a round base, a plurality of convolute lugs on the base, and a plurality of involute lugs on both sides of the base. The base is preferably disk shaped, and the convolute lugs are preferably aligned with the involute lugs. In the preferred embodiment, a number of convolute lugs is one half a number of involute lugs. The convolute lugs should line up with windows in a track for the snowmobile, and the involute lugs should line up with gaps between knobs on the track for the snowmobile. Preferably, the sprocket also includes a hub with a through hole for a drive shaft and stiffening arms radiating from the hub.