I'm currently putting together a bike for touring and for a few Duathalons. It is a med Giant TCR Aero 1 with Centaur Groupo. My Question is what size of crank will I go with. My current ride is a 1989 Concorde with Campy that has a 170 crank. I also have a second bike, a Gardin with Shimano 105. This has a 172.5 crank, and I tend to like the feel of that. Does a riders size, weight or type of riding have any bearing on crank length, or is it all just preference. I am 5'10", 185lbs and have an inseam of 83cm (32in). Any advice would be appreciated.