Kettenhund

Greetings! I recently received a Tamiya Renault 5 turbo in excellent condition from a friend of mine. The motor was burned up, so I purchased a GoolRC 4750kv motor and esc. I installed them today and drove the car around on the old hard foam tires. That thing flies! Unfortunately, the tires are hard and flat spotted, so it was almost uncontrollable at speed (I would guess a top speed of more than 70mph). After scrubbing the tires in on concrete for 5 minutes or so, the grip increased 10 fold. I am having problems finding replacement tires and/or wheels for this car. I can find originals, but they are $30-40/pr, and I am sure they are hard with age. I need to know where I can get foam tires that are 55mm o.d., 36mm I.d., and 44mm wide, wheels with a 9mm hex hub, or an adapter to adapt 9mm hex hubs to 12mm so I can use modern wheels. Can anyone help? I would love to drive this little pavement monster again soon... I blew up a tire today due to poor gluing and very high wheel rpm.