Snowmobile

1. A snowmobile, comprising:

a chassis, comprising a bulkhead and a tunnel;

an engine supported by the chassis;

a front suspension coupled to the bulkhead;

a rear suspension coupled to the tunnel; and

slide rails coupled to the rear suspension;

the rear suspension comprising:

a toggle link pivotally coupled to the tunnel at a first pivot coupling, and a rear control arm coupled between the slide rails and the toggle link, the toggle link being pivotally coupled to the rear control arm at a second pivot coupling;

a carrier roller directly coupled to the toggle link, the carrier roller being movable to a plurality of positions relative to the toggle link to vary propulsion dynamics of the vehicle; and

a front control arm coupled between the slide rails and the tunnel.

2. The snowmobile of claim 1 , wherein the toggle link has a front and rear coupling link, and the carrier roller is mounted in a position generally lower than the front and rear coupling link.

3. The snowmobile of claim 2 , wherein the carrier roller is mounted in a position generally centrally located relative to the front and rear coupling link of the toggle link.

4. The snowmobile of claim 2 , wherein the carrier roller is mounted in a position generally rearwardly located relative to the front and rear coupling link of the toggle link.

5. The snowmobile of claim 2 , wherein the carrier roller is mounted in a position generally forwardly located relative to the front and rear coupling link of the toggle link.

6. The snowmobile of claim 1 , wherein the carrier roller is movable within a box-shaped range defined relative to the first and second pivot couplings.

7. The snowmobile of claim 6 , wherein the box-shaped range is positioned below a reference line (R) which extends between the first and second pivot couplings.

8. The snowmobile of claim 7 , wherein the box-shaped range is positioned between lines (A 1 , A 2 ) below the reference line (R).

9. The snowmobile of claim 8 , wherein the line A 1 is approximately 80 mm.

10. The snowmobile of claim 8 , wherein the line A 2 is approximately 225 mm.

11. The snowmobile of claim 7 , wherein the box-shaped range is positioned rearward of a tangent line (T) which extends through the first coupling, and is tangent to the reference line (R).

12. The snowmobile of claim 11 , wherein the box-shaped range is positioned between lines (B 1 , B 2 ) rearward of the tangent line (T).

13. The snowmobile of claim 12 , wherein the line B 1 is approximately 60 mm.

14. The snowmobile of claim 12 , wherein the line B 2 is approximately 225 mm.

15. The snowmobile of claim 1 , wherein the carrier roller is positioned 99-320 mm below the first pivot coupling.

16. The snowmobile of claim 1 , wherein a rotational axis of the carrier roller is positioned away from the first pivot coupling by a distance along a reference line R, and a length of the toggle link between the first pivot coupling and the second pivot coupling equals D, and wherein a ratio of R/D is within a range of 0.34 to 1.097.

17. The snowmobile of claim 1 , further comprising an endless track operably coupled to at least a portion of the slide rails and the carrier roller is positioned interior of the endless track.

18. The snowmobile of claim 1 , wherein the toggle link includes a plate and the carrier roller is coupled to the plate.

19. The snowmobile of claim 18 , wherein the plate includes a plurality of holes and a center of rotation of the carrier roller is aligned with at least one of the holes.

20. The snowmobile of claim 18 , wherein the toggle link has a front coupling link and a rear coupling link, and the plate is positioned between the front and rear coupling links.

21. The snowmobile of claim 18 , wherein the carrier roller is directly coupled to the plate.