Track system for attachment to a vehicle

A track system for attachment to a vehicle including:

• I) a vehicle chassis having a front portion, a rear portion, a left side, and a right side;
• II) a rear suspension having a swing arm attached to the rear portion of the vehicle chassis, the swing arm being moveable between a compressed-suspension position and an extended-suspension position;
• III) an engine supported by the vehicle chassis for providing motive power to propel the vehicle;
• IV) a rear axle being in driven connection with the engine;
• the track system comprising:
• a) a track system frame being pivotably attachable to the swing arm about the rear axle, the track system frame having an upper frame portion and a ground-facing frame assembly, the ground-facing frame assembly having a leading idler wheel assembly and a trailing idler wheel assembly attached thereto, the ground-facing frame assembly having a longitudinal angular position relative to the vehicle chassis when the track system frame is pivotably attached to the swing arm;
• b) a drive sprocket being in driven connection with the rear axle when the track system frame is pivotably attached to the swing arm;
• c) an endless track mounted around the drive sprocket, the leading idler wheel assembly, and the trailing idler wheel assembly, the endless track being in driven connection with the drive sprocket;
• and
• d) a dynamic traction device having:
• i) a first elongate portion having a first distal end, and
• ii) a second elongate portion having a second distal end opposed to the first distal end, the second elongate portion being movable relative to the first elongate portion between a retracted position and an extended position, the second elongate portion being biased toward the retracted position,
• iii) the first and second distal ends being closer together in the retracted position than in the extended position, and
• iv) when
• A) the track system frame is pivotably attached to the swing arm,
• B) the drive sprocket is in driven connection with the rear axle,
• C) the first distal end is pivotably attached to the vehicle chassis at a first attachment point, and
• D) the second distal end is pivotably attached to the track system frame at a second attachment point,
• the first attachment point and the second attachment point are located with respect to the vehicle chassis and the track system frame such that when the vehicle is lifted off terrain, during at least a part of a movement of the swing arm from the compressed-suspension position toward the extended-suspension position, the dynamic traction device applies a torque to the track system frame about the rear axle and thereby changes the longitudinal angular position of the ground-facing frame assembly counter-clockwise relative to the left side of the vehicle chassis.