Profile Design has long been a name in the world of a variety of aero products, but has only been a name in the wheel market since last year. Yet given its aero history, the addition of deep-section wheels to its ensemble isn’t such a stretch. The Altairs are the company’s premium wheel offering and come in two different depths, 52 and 82mm, and three rim variations, full-carbon tubular, full-carbon clincher and our test wheels, a co-molded carbon and aluminum rim called ‘Semi Carbon.’
The entire range of Altair wheels all share the same hubs and spokes; the rims are the only defining characteristic between the different wheels. The full-carbon clincher version has been Profile Design’s best-selling Altair model to date, yet the Semi Carbon sells for $200 less and weighs approximately 100 grams more. While it’s true that all the attention has been turned to full-carbon clinchers as of late, there are still plenty of riders who don’t mind the additional weight in order to get the practicality and confidence of an aluminum brake track in a deep-section wheel. Unlike nearly every full-carbon clincher, the aluminum brake track doesn’t requireproprietary brake pads. And although the braking consistency of a carbon rim in wet weather is continually improving, it still doesn’t match the stopping power of aluminum.
One of the nicer details of the wheels is the spoke that Profile Design chose to use. The spokes come from Belgian-maker Sapim, and are regarded as some of the highest quality stainless steel spokes available. Both the 20- spoke front and 24-spoke rear hubs use cartridge bearings, and as one would expect in this price range, the rear features an aluminum freehub body. Putting the pieces together is something that is very important to Profile Design, and that’s why all their wheels are hand
built. There are two reasons for hand-building the wheels according to Profile Design’s Barry Smith: ‘First off, we want to be confident the build quality of our wheels would last our customers for years-you can’t always get that with machine-built wheels. Second, we don’t want to be getting wheels back that aren’t holding up; that’s not good for anyone.
The Altair Semi Carbons are laterally stiff and don’t waste precious energy in flex under acceleration. But when the speed slows from the pitch of the climb, the wheels’ stiffness and aerodynamics do little to help.
Comfort was in line with the majority of wheels in its depth range, which ends up yielding a less compliant ride than a shallow-section aluminum rim. At 100 psi in the 23c Maxxis Cormets we used, the wheels still rolled fast and didn’t feel harsh over rough patches of road.
Feel between the stout rims and an adequate number of spokes (20 front and 24 rear), the Altairs felt solid. There wasn’t any dead or soft feeling when laying into a corner that can sometimes be felt on wheels lighter than the Altair Semi Carbon.
The Altair Semi Carbon’s machined, aluminum brake track was smooth without any uneven areas in the rim’s surface that can cause pulsation when grabbing a handful of brake. Dry-weather braking power wasn’t any better than on the leading carbon rims. But one rain ride reminded us that even with reduced stopping power in the wet, it was still better than carbon.
At 52mm the Altair falls into the mid-aero depth range. This means that although the front wheel will get pushed around in extreme conditions, crosswinds of less than 20 mph won’t cause much of an issue in handling. In windier conditions, the sharp nose profile ends up being jostled around more than a rim with rounded nose shaping.
Co-molded rims are not a new product on the market, and the main reason for their popularity is that they’re durable. They’re probably a better choice for criterium racing than a full-carbon rim since, chances are, they’ll come out of a wreck without catastrophic damage.
The Altair Semi Carbon is a versatile, jack-of-all-trades wheelset capable of delivering worry-free miles while providing an edge aerodynamically. In most situations, aerodynamics trump weight-that is, until the speeds drop below 15 mph. And when that happens, the weight difference between a full-carbon clincher and the Semi Carbon manifests itself. Profile Design did a good job making the wheel competitive in price and weight within its own category-even against longstanding brands such as Mavic (who don’t make a full-carbon clincher)-and instead focused its attention on the 52mm-deep Cosmic Carbone co-molded wheels.
The Altair Semi Carbon compares well with the Cosmic Carbone SLE, which costs $1699 (including tires), and weighs 1755 grams (claimed).
Weight: 1838 grams, plus 114-gram quick releases
Rim depth: 52mm
Rim width: 20mm
Spoke count: F-20/R-24
Spoke type: Aero stainless steel
Spoke pattern: F-radial/R-radial non-drive side and 2x drive side
Notes: Available for Shimano/SRAM (a Campy freehub costs an additional $110). Includes quick releases, valve extenders and spare spokes.
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