At our track, the spec tire from Contact that fits the hex axle works just as well as the CRC tire and is cheaper. I like the easier tire changes with the single wheel nut vs 3 screws. However, you can get the 3 hole hubs from Schumacher if you want to use those style wheels. I have both. I use the contact tires with the hex when possible and the 3 hole hubs when necessary.