have aluminum rims. last month 3 wheels started leaking. kept tires aired up but one went down on rim. kid drove it 2 blocks and pulled into parking lot. flat. got air tank and blew it up but seems damage was done. took it to shop to reseal bead area but shop showed me 2 large hand fulls of shredded rubber and lots of inside cord damage. grr. tires are at about 1/2 tread. found real nice used tire. same tread pattern. keep an eye on air pressure.