[balrock043]

our team uses spacers mounted to the bumpers then to the robot. we use 14 ply baltic birch plywood as a backing.4 pins set into the wood extend into the frame of the bot, and are fastened with cotter pins, and screwes/knobs at the rear of the chassis. we made 2 sets (red & blue) embroidered with our team number. they actually came out quite nice, and only gave us one problem, which was remedied with the spacers..

for the sake of identifying alliances, the requirement for different colored bumpers was convenient for the audience and judges, but it was a pain to build double the bumpers.

in terms of materials, i think plywood is the best option. using plastic/fiberglass/polycarb would be far too flimsy. using aluminum would be a poor and difficult surface to work with in terms of bonding, and would add to much weight (and potentially rip the fabric).