Streamlined bodies that let the airflow reattach smoothly behind them experience much less drag than bluff bodies to which the airflow cannot remained attached, creating a low pressure zone behind them that literally sucks them back. There is no doubt that the deep section rim creates a streamlined shaped behind the tire, whereas the conventional square rim is definitely a bluff body. To conclude on this topic, even though our testing produced drag results that are, in absolute terms, much below those that can be expected in real life, we believe that it did reveal a useful relative ranking of the test specimens. Other factors affecting performance are not so tricky to evaluate. Weight, for instance.
Weight is a key performance factor in climbing.
In this regard, conventional wheels still remain the top choice. A lightweight hub and a lightweight rim made the 36 spokes wheel the lightest in the group, at 1030 grams. It beat the 32 spoke wheel by 30 grams. The Shamal, thanks to its jewel like miniature hub and lowest spoke count of the group, is remarkably light at 1090 grams. Other aero wheels all weighed around 1200 grams, except the Specialized.