No I havent.. I would say that axle will be changed first due to time and idk wht it will do tomorrow.. if on chip tom at track I'm going to change axle and then figure out ratio to get front sprocket and axle to tht ratio.. everyone at track seems to run 14-49 and I'm running a 13-49 so I'm a little off.. was thinking I'd try that cuz that's what my bud ran.