Originally Posted by
merlinextraligh
I'd go with the 404's. Thy're more aero than the 303's and the weight difference is only 100 grams or so.
This was my reasoning. Plus, if I was going to shell out the cash for "Aero" rims, I didn't want to be second guessing the 303's aero benefits. 404's seemed like the best compromise. Even at 4-5% grades aero still trumps weight. I was trying to balance a TT'ing with riding mountains tho.