Try this
Ok, we used to race on a SMOOTH concrete track in the winter and this is what worked the best for us.
First I should ask you in you have any rules as far aas tires go because this is a little different than the norm.
Ok hear goes.
1. Buy a set of purple foams for both the front and rear of the car.
2. True them down to what ever size you like. 2.250 always worked good for us.
3. Radius the edges with about 1/8" radius
4. Find silicone sealant for windshields' I belive it was from Dupont or 3m
5. Apply 3 THIN coats for sealer using your finger to smooth it out.
5. Allow each coat to dry before adding any more.
6. Make sure the silicone is as smooth as possible, small ridges are ok.
7. Go have fun!!!!
It might seem like alot of work but we never found anything to provide as much traction as these tires did.
Chuncking was never a big problem either.
I word of advice try to find the silicone for windshiels as it is considerably thinner and easier to work wiht than normal silicone. It is clear and the tires will "wear in" after the first couple battery packs. After the first race day or two the small ridges will be warn off and the tires will work even beter.
Oh and no traction compound is needed.
It might be alot of work but the resuls should prove to be worth it.
Good Luck