Patent ID: 7128180

Claim:
A rear suspension system for a snowmobile having a chassis enclosing a drive system and a rear tunnel that is about 17-inches wide, the rear suspension system comprising: first and second adjacent closed-loop tracks disposed in the tunnel and rotatably driven by the drive system; a first independent suspension assembly disposed in said first closed-loop track and a second independent suspension assembly disposed in said second closed-loop track, said first and second independent suspension assemblies allowing independent movement of said first and second closed-loop tracks and maintaining said closed-loop tracks at a generally uniform tension during movement of said rear suspension system; a front elongated cross shaft extending transversely through each of said first and second closed-loop tracks and coupled to the elongated chassis, said first and second independent suspension assemblies coupled to said front elongated cross shaft, said front elongated cross shaft providing a centerline of rotation for said first and second independent suspension assemblies; a rear elongated cross shaft extending transversely through each of said first and second closed-loop tracks and coupled to the elongated chassis; a pair of elongated ground contacts disposed in each of said first and second adjacent closed-loop tracks; a first elongated swing arm disposed in said first independent suspension assembly and a second elongated swing arm disposed in said second independent suspension assembly, each said first and second elongated swing arms having a first end pivotally coupled to said front elongated cross shaft and a second end adjustably coupled by a tensioner to said pair of elongated ground contacts; a front resilient member having a first end coupled to said swing arm and a second end coupled to said pair of elongated closed-loop tracks; a rear resilient member having a first end pivotably coupled to said rear elongated cross shaft and a second end coupled to said swing arm; a first stop coupled to said swing arm, said first stop for preventing contact between said swing arm and said pair of elongated ground contacts; and a second stop coupled to said rear elongated cross shaft, said second stop for preventing contact between said rear elongated cross shaft and said swing arm.