the radiator would have "cluttered" this sleek bike and would have gotten away from the scheme of the bike. water cooling is definately a good thing, but is more expensive, and the price of this bike is very reasonable. a "good" oil cooler can drop the operating temp as much as 100 degrees over an air only bike. having said that, there is a multitude of bikes with thousands and thousands of trouble free miles that have neither. comes down to preference, and or geography.