Originally Posted by f4rrest

The modeling here demonstrates that aero is much more important than wheel weight, even riding uphill at 17mph.
http://www.biketechreview.com/archive/wheel_theory.htm



There are some other articles on that site that show lightweight wheels start to make sense when the hill is really steep (around 15% gradient), but it depends somewhat on how fast you can travel uphill as well.

Originally Posted by urbanknight

You just opened Pandora's box. It seems that most people claim 42mm, but I'm pretty sure than came from an advertisement from a company that makes 42 or 43mm deep rims. I have a feeling that it's a sliding scale, like bringing a frog in water to a slow boil. You also have to realize that the depth of the rim is not the only determining factor either.

I stopped worrying about it. I bought some 19mm deep rims for my next build. Why? Because I want to tell people I have a sub 1400g set of wheels (just so I can), and even a 100mm deep rim wouldn't make my slow @$$ win any races anyway.