Something that also works rather well is to have connected bumper sections connected via a hinge.
For example, on our 2012 off season robot, we had a cutout in the front of the C-Frame, to pick up the balls. our bumpers were in two parts, each covering one long side, one short bit at the front of the robot and half of the back.
The connections between them were hinged. That enabled us to bend the outer two pieces of the bumper out a bit more, making it far easier (and less frustrating
) to put on.