The 21h Andrew chain drive cams from brands for Harley Davidson Dyna models from the years of construction 2006 to 2017 increases the torque and optimizes the engine output for the versatile use. This accessory is ideal for motorcycles with standard compression ratios and pistons. It is characterized by a performance similar to the camshaft for EV 80, which works in the speed range from 1700 to 4800 rpm. In addition, use with the standard valve springs is possible.