Abstract: A snowmobile suspension system used to suspend the drive belt of a snowmobile between extended and retracted position is described herein. The snowmobile suspension system is provided with a pair of side rails to guide the drive belt, a pair of suspension arms each having a proximate end pivotally mounted to the snowmobile and a distal end pivotally mounted to both side rails, shock absorbers and compression springs provided between the side rails and the snowmobile to bias the side rails towards their extended position, and a progressive spring assembly mounted to the side rails to prevent forceful contact between the side rails and the undersurface of the snowmobile. The side rails are advantageously made of composite material and present a concave undersurface. The pivotal attachment of the distal end of the rear suspension arm to the side rails is advantageously made via an adjustable cam assembly allowing the user to modify the characteristics of the snowmobile suspension system.

Abstract: A rear suspension system for a land vehicle comprising a single generally centrally mounted structure in a middle portion of the rear suspension system. The suspension system comprises a pair of inclined primary suspension means, and a pair of inclined primary oscillating arms for pivotally connected to a pair of laterally spaced longitudinal slides at an underside area of the chassis of the land vehicle. Each of the primary oscillating arms comprise a distal end, which are further coupled to a horizontal bar adjacent a distal end of the primary suspension means, such as a shock absorber, and a proximal end which are individually mounted a horizontal bar adjacent a front end of the primary suspension means at an underside portion of the chassis. The suspension system further comprises a Weight Transfer Dynamic Compensator for raising a front tip portion of the longitudinal slides each time there is a transfer of weight in the vehicle.