GRAVEL Whether your route covers rough roads or fast gravel, or even both in the same day, Washburn is built for the job. Its center slick provides awesome rolling efficiency on pavement and packed dirt, while the shoulder lugs take over in the turns, digging in for confidence in loose corners. HOW IT WORKS - Center tread is smooth to minimize rolling resistance and maximize speed. - Transition lugs are tightly spaced to provide progressive initial cornering traction. - Side lugs are spaced out to dig in while cornering and when riding over loose surfaces.