If your looking for other tire options for asphalt racing, try out the Yokomo CRT tires.So far, I've had great success with the Yokomo CRT's tires. First outing with the CRT's yielded the fastest lap times and were consistent throughout the 8 minute main.
Before jumping on the CRT line, I was using Team Bomber tires for 3-4 months with good results, but they tend not to be as consistent as the CRT's.
Interestingly, the hot setup here in Japan is Kawada foam tires, unfortunately they cost an arm and a leg.
