Bumper system

A rear-collision protection system is described. The rear-collision protection system is for a vehicle with a frame on which at least one rear wheel is disposed. The system includes at least one mounting (9a,9b,10a,10b) connectable to the frame, the mounting being pivotable about a first axis (A). It also includes at least one collision roller (7a,7b,8a,8b) supported on the at least one mounting, the collision roller being rotatable about a second axis. The collision roller is disposed adjacent to the rear wheel.