Any tips for a newbie trying to get the crusty bits of old tires and tubes off a rim? Had to cut the tire off and it was a shame. Hurts me to do so but I had if I ever want to ride this bike. It had a U.S. Royal Master Centipede Grip on the front but it was toast. The back tire is so far gone you can't even read a name. It looks like soup boiling over in places. Any help figuring out an easier way to get the old stuff off would be appreciated. Right now I am just chipping away at it with a small chisel but thought one of you pros would have a better way.