HED Jet Disc Wheel
- Item: HED0048 Claimed Weight:"Claimed Weight" is an unconfirmed weight provided by the manufacturer. 1210 g
Disc wheels are where Steve Hed got his start. The Jet disc is the first wheel he offered in 1987. It was impressive then. It's more impressive today. The HED Jet Disc you see is an update of the original Jet. It takes the same basic idea and construction and adds all the knowledge that HED has accumulated over the years to a Jet Disc that's basically just fast. The new shape debuted in 2007 and saves five seconds over the old shape in a 40km time trial.
The Jet Disc uses a hybrid construction. 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 one fast wheel that is not only extremely durable but very stiff in the lateral plane. This lateral stiffness should add 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 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. HED says that 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. If you choose to go the clincher route, 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.