Riders know that tires with the sides nicely scrubbed in, rather than worn flat in the middle, are evidence of…what, exactly? More experience? More adventure? More fun? Rear tires ridden right out to the edges, with that well-worked, textured pattern etched into the rubber from deep leaning and hard acceleration, garner secret admiring glances and plainly communicate one thing—this rider has some brass. Freud might have called this condition "tread envy."