the longevity of your cranks, the stiffness of your crankarms, durability of your chainring bolts and the overall weight are all practical reasons to get 75's over RD's. i lost a crankarm going through an intersection a while back and now i won't use anything less than Sugino 75's.

also, the Grand Mighty chainrings are the only ones you can get that are perfectly circular. i mean perfectly. i'm not 100% positive of this, but i also believe they're a higher grade aluminum than the 75's. if you're not planning on doing velodrome racing with an insanely high gearing, the grand mighty's are probably overkill. but they do look sweet.


but if you're riding under 100 miles a week and don't do a lot of sprinting, i'd say the sugino RD is a perfectly justifiable option.