Copied from Slowtwitch:
There is no fork that "does it all" for a triathlete. The Carbon Airfoil does one thing particularly well. Its deep trailing edge, which extends far back behind the rake line, appears to act as a counterbalance to the forces the wind exerts on the part of a deep rim exposed in front of the fork. This means that if you use a deep rim on your front wheel and combine it with this fork, your bike will handle better on a windy day.
An example of this might be, say, if you wanted to ride a Hed Deep on the front during the Hawaiian Ironman. Such a tactical move would require some cajones and a fork like this.
The photo at left is actually the all-aluminum version of this fork, which you don't want (too heavy). You can see the faint lines just below the crown where the blades meet the crown, and also lines where the bottom of the blade meets the dropout. The carbon version of this fork has carbon legs which replace the aluminum ones.
A Hed Deep would be a mighty fast wheel on a day with crosswinds whipping across the lava fields around Waikoloa, but only at a cost of heeling your bike like a sailboat in a broad reach. Okay, we're succumbing to hyperbole. But it can be a bit hairy out there if you're sporting a lot of surface area on a windy day, and this fork would help keep your bike on the road.
How do we know this? Because in his fork testing Herr Air John Cobb had the foresight to rig an extra scale up to the fiixture that mounts the fork holder to the turret in the wind tunnel. In so doing he not only measured the fork's drag, but the torque required to keep the fork fixed in place during a yaw. He performed this testing while using a variety of fork and wheel combinations. There was less pressure applied to the scale using this fork, indicating that the wind on the road would exert less force pushing the front of the bike leeward.
This is cool, but it comes at a price. The Carbon Airfoil weighs. Even though it's legs are carbon, it's crown is a forged of a piece of aluminum that––well––we heard container ships use them to keep themselves at anchor in Taichung harbor. The fork does now finally come with a carbon steer column, and this takes the 700+ gram Carbon Airfoil and reduces it to about 570 grams or so. Compare this, though, to the Profile Design's and Reynolds Composites' forks that weigh in the neighborhood of 400 grams. That's a difference of almost a half a pound.
This fork was originally the Carbonaero, and was commissioned by Quintana Roo. Kinesis built the fork specifically for that company. It was a good enough fork that both Cannnondale and Trek paid extra to be able to spec it on their tri bikes, and QR got a royalty of every fork sold to each of these two arch competitors.
Before you start thinking this its extra weight makes it a less-desirable fork, just remember that Lance Armstrong rode this fork during his time trials in the Tour, and not just in his first Tour victory, but his next one as well.
It ought to cost between $225 and $250 with a steel steerer, and perhaps an extra $50 to $75 with a carbon steerer.
