I'm about 5'9-5'10 and i use 172.5mm cranks at the moment. I have a 175mm dura-ace crank however that's brand new laying around my apartment. I've been told that the 175 would hurt me more than help me but i would like some more people to weigh in. My pants are 30 or 32" inseam if that helps any. I Figured i could lower my seat height a little and the 2.5mm crank arm difference wouldn't be that big of a deal?