74 Main Street Middlebury Vermont (802) 388-6666
Which is more important, weight, or aerodynamics?
The faster you go, the more important aerodynamics become. In a 20mph group ride where some riders have shallow rims and others have deep, the advantage of the deep rim isn't significant. At 30mph, however, it's a different story. This is why you see so many deep rim wheels ridden in flat stages in events like the Tour de France.
When the road pitches up to 8 percent or more, you'll appreciate the way a light wheel helps you keep your speed up. If you're willing to glue your tires on, you can have your cake and eat it too. The tubular versions of the ENVE 45 and ENVE 65 are not only aerodynamic, but also quite light. The ENVE 45 clincher gives you a sub-1400gm weight and a 45mm deep rim -- your best bet for a "have your cake and eat it too" clincher.
If you want to stick to aluminum rim clinchers where flat roads are rare, a shallow rim is the way to go. Of all the aluminum clinchers we've tried, the one that comes the closest to a carbon tubular when climbing is the Topolino CTR2.0, which you can try at our shop. Despite the shallow rim, they're also quite nimble on the flats, thanks to low rolling weight and good bearings.
As for an aluminum deep rim? The weight is prohibitive, so we rarely see aluminum rims much deeper than 30mm.
An aluminum rim with a carbon fairing combines the aerodynamic advantages of the full carbon deep rim with the superior braking of aluminum. Mavic's Cosmic Carbone clinchers use this type of rim and are great for flat and rolling courses. Rim weight hovers right around 500gm, however, and there's too much inertia in a 500 gram rim to make it a true all-around wheel. These are best for rides where the goal is to get up to speed and then stay there, as in a triathlon or a time trial.
The inertia of the heavier rim can be an advantage for holding speed on the flats, but the inertia is hard to overcome when you're going uphill. You won't accelerate as fast, and it will be harder to maintain your pace. We don't recommend this type of rim for Gap rides, but for riding around down in the valley when high average speed is the goal -- or for your midweek evening time trial series -- these wheels are quite fast.
Deeper all-carbon clinchers like the Enve 65 or the Zipp 404 also hover around 500 grams.