2011 Martinsville: NASCAR Sprint Cup - Tires Have Cup Drivers Skittish

 Sprint Cup drivers say they are concerned about tires for Sunday’s race as the Goodyear tires are leaving marbles of rubber on the track and have not rubbered in the Martinsville Speedway.The .526-mile racing surface is a mix of asphalt with concrete corners. Goodyear brought a different tire to prevent grating on the left-side tires as they slide across the concrete. Softer right-side tires