DetailsHigh Roller:~ Soft terrain tire for front or rear. Ramped knob design lower rolling resistance. Grooved center provides straight-line control. The 3C is a triple compound (70/42/40) durometer tire for downhill use. 42a is a Super Tacky 42 durometer, 27tpi single-ply casing. DH models have a tough, 2-ply casing and butyl sidewall reinforcement.