In some conditions in off-road racing, there is no denying that a slick tire is the fastest way around the track. Indoor, and occasionally outdoor, clay surfaces become so tacky or free of dust and debris that a total slick tire is an advantage. For years drivers have sanded, ground and hand sculpted tires in search of that elusive slick carcass. Now, JConcepts has already done the work with the Smoothie 2.