It's a 3 inch wide rear wheel? A bead lock might be an option, generally they weigh about 3 1/2 ounces, so it might be a challenge to balance, depending on where it wants weight in the first place. Finding a 3 incher might take a little effort as well, most manufacturers only go to 2.5. The only other real option would be to run higher pressures, which would compromise traction a bit, or go old school and use short sheet metal screws into the beads like drag guys do with car slicks.