I agree with MikeR. Tamiya B2's suck. At TCS North American nats, my fast lap with B2's was 15.3. At the Reedy race (virtually same layout) with Take-Off CS27 my fast lap was 14.4. I never timed the Sorexes, but they are even more hooked up than the Take-Off's and they last longer. Get some Sorex!