Tracked Vehicle

A snowmobile assembly, comprising:

• a chassis assembly having a tunnel assembly;
• a skid plate assembly having a skid plate surface;
• a track having a contact surface configured to propel the chassis and a skid surface configured to contact the skid plate assembly;
• an engine housed at least partially within the chassis assembly configured to drive the track;
• a driveshaft connection;
• a suspension assembly configured to connect the chassis and the skid plate assembly in a moveable manner, the suspension assembly including:
• a first torque arm extending from a first end to a second end;
• and
• a second torque arm extending from a third end to a fourth end;
• wherein the first end is fixed to the chassis assembly at a first fixation point such that the first torque arm is operable to rotate about the first fixation point;
• wherein the third end is fixed to the chassis assembly through a linkage assembly rotatably attached to the chassis at a second fixation point;
• wherein the third end is configured to be coupled to an upper guide roller assembly;
• wherein the fourth end is connected to the skid plate assembly;
• wherein a drive shaft line is defined between the second fixation point and the driveshaft connection;
• wherein a second torque arm line is defined by the second torque arm between the third end and the fourth end;
• wherein a torque arm line angle defined between the drive shaft line and the second torque arm line that changes as the skid plate surface travels between a full extension position and a full collapse position, the torque arm line angle configured to change by 36 to 46 degrees between the full collapse position and the full extension position;
• wherein a first length, defined from the second fixation point to the driveshaft connection, is in a range from 30 to 34 inches;
• and
• wherein a second length, defined from the first fixation point to the second fixation point, is in a range from 22 to 24 inches.