Originally Posted by cny-bikeman

It's not wise to lengthen a chain in order to reach the small-small combo, particularly when running a 9 tooth. That combo engages the fewest teeth of any, increasing wear by a large amount. In addition the high gear should not be used very often at all, certainly not for acceleration. I'm sorry, but it's absurd to be running a 53-9 at all (38 mph at only 80rpm) and certainly pushing any high gear into a headwind indicates questionable judgment. Even a 48-9 is only appropriate at speeds exceeding 35 mph.