Steve Hed, the mastermind behind the wheels of HED cycling, first offered a disc wheel in 1987. Yes, almost three decades ago. And as impressive as his wheels were then, think about what 27 years of continual development and refinement have brought to the design. The HED Jet Disc Clincher Wheel is an update of the original Jet which, as it rolled, was already fast. The shape was re-engineered in 2007, and has since stood the test of countless athletes.
The Jet Disc uses a hybrid construction, which makes it extremely durable. The wheel begins with a 24-spoke hub HED Sonic hub, 24 14-gauge spokes, and a 24-spoke C2 rim. Once the wheel is built, two carbon fiber lenticular panels are fitted over the spoked structure. The toroidal bulges in the rim section flare out to 26mm at their widest. Once the construction is completed, you have a fast wheel that is not only extremely durable but very stiff in the lateral plane. This lateral stiffness adds to drivetrain efficiency, propelling you forward with very little energy loss.
The rim is HED's C2 aluminum rim. It's available in clincher or tubular. As with all HED's C2s, this rim is 23mm wide. C2 stands for the two C's that the rim is designed to minimize, Cda, or aerodynamic resistance, and Crr, or rolling resistance. The width is designed to maximize the efficiency of air passing over the tire and rim by smoothing out the air flow as well as maximize the efficiency of tires by providing better support and a better-shaped contact patch for the tire. Because of the width, you'll minimize rolling resistance and maximize aerodynamics by using 22-23mm wide tires. 19-21mm tires won't ride well, and they're also not a great idea as they won't seat well.
When the wheel is spinning, the air will flow smoothly over the tire and the bulged rim wall where it speeds up a bit. It then moves on to the lenticular sides where it stays pretty smooth. HED has found that the lenticular sides do better in crosswinds than flat-sided discs.
In terms of aerodynamics, the Jet Disc crushes your standard 32-spoke wheel and bests every deep section wheel out there. HED's research has found that the wheel does best at yaw angles in excess of five degrees, with the sweet spot ranging from 15-20 degrees. To give you a sense of how fast that is, the wheel has 25g of drag at 15-degrees of yaw when riding at 40kph. That's 195g less drag than a conventional wheel. That's an 18w savings for every second you're riding.
The HED Jet Disc Wheel comes with a steel-shafted HED quick-release skewer and a valve extender. The tried-and-true Silca "crack pipe" disc wheel adapter fits great in the opening. The cassette body is available with Campagnolo splines or with Shimano/SRAM splines. You'll need to buy a rim strip as HED doesn't supply it with the wheel. They suggest anything that is 20-22mm wide; we carry 22mm wide Velox tape.