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By now, we’re all pretty well versed with the benefits of aerodynamic equipment for road riding. But for gravel riding, aerodynamic frames and wheels have not yet caught on to the same extent. Even though the tires are bigger in off-road situations, there are still aero benefits to be had, and wheels are one of the most obvious places to save those precious watts— whether you’re going to be riding 20 miles at a time or 200.
Having made hubs and spokes for a variety of brands for years, in addition to its own wheels, DT Swiss is no stranger to high-quality, speedy hoops. With the emergence of off-road riding, the company saw a need for gravel-specific wheels and released a whole suite of new wheelsets. The flagship model of the group is an aerodynamic set measuring 42mm-deep called the GRC 1400 SPLINE 42. It’s meant for serious gravel racers, or those who just like to go as fast as possible all the time.
Working with Swiss Side on aerodynamics, DT Swiss developed a rim shape fastest on gravel surfaces. The collaborative research shows that 35mm slick tires provide the optimal aerodynamic benefit for gravel riding while balancing the other important aspects of gravel tire ride quality, like traction and comfort. Of course, 30mm tires will offer more aerodynamic benefit, but at a much larger tradeoff to ride quality. And going in the opposite direction towards wider tires, there is still some aero benefit to be had, though it is lower.
Speaking of ride quality, DT Swiss has optimized these rims for off-road purposes by widening them out to 24mm, a move which we’re seeing many wheel brands implement. The wide rim bed helps reduce rolling resistance by widening out a tire’s stance, therefore reducing the contact patch area of a tire. With the same 35mm slick tire at the same pressure, a 24mm-wide rim reduces rolling resistance by 5 percent to 7 percent versus a 22mm-wide rim. A wider rim also provides more sidewall support, as well as a wider, shorter tire contact patch which increases cornering traction.
DT Swiss pairs these rims to its excellent 240s based Spline hubs with its DT aero comp spokes laced in a 24×2 pattern for increased stiffness. The set weighs in at 1,640 grams and costs $2,479.
We were a little skeptical of the aerodynamics of this wheel off-road because we were running 40mm-wide tires with some aggressive tread, not the optimal 30mm-35mm slick tires DT Swiss recommends. But we were proven wrong. Despite the wider tires, these wheels felt very swift both off road and on. We found that to be a huge benefit on routes alternating between sectors of gravel and tarmac. On descents, the speed is especially noticeable as you gradually pull away from anyone not employing aero rims. And the DT Swiss 240s hubs are also noticeably great, seemingly rolling on forever.
Where we test ride gravel, we generally prefer wider, more substantial tires, so 35mm slicks usually aren’t an option for us. But if that suits the terrain you like to ride, this wheelset will provide an even bigger boost.
$2,479; 1,640g; dtswiss.com