Interbike '08: Hed Cycling

We got to talk to Steve Hed for a really long time this year. This, to me, is the equivalent of a long moonlit walk on the beach with Thor for Schmalz. Hed threw so much stuff at us it made my head spin, while Schmalz did his usual 'dog staring at radio' routine. Hed will be in NY later in the year, we're going to try to get him to give us a seminar while he's in town. Here's some highlights from our talk:

Hed is moving towards wider rims for a few reasons. First of all, they blend better with the tire for superior aerodynamics. Secondly, wider tubular rims have a deeper tire well. This gives it more gluing surface, allowing you to use less glue, reducing glue squirm, a source of energy loss. For clinchers, wider rims change the shape of the inflated tire, producing a wider contact patch. This means for a given psi, you'll get a wider and shorter contact patch. The shorter contact patch should have less leverage to push back against the axle, meaning less rolling resistance. Also, at 1360 grams, the Ardennes are lighter than Campy Hyperons, at a quarter the price.

Hed's new aerobars are in their 2nd year, and this year they have integrated brake levers with a built in return spring. The base bars are available flat or with a drop. The dropped version is for better weight distribution and handling on technical courses. There are a variety of extension shapes, including a unique 'Lazy S' shape that Hed really likes. For Hed, extension shape isn't just about hand position. He thinks different shapes have an effect on how you hold your shoulders. He also doesn't believe in a static aero position – riders should have slippery positions for certain times, and more powerful positions for others.

Hed laments the ubiquity of wind tunnels. He prefers having riders work out their positions on their own, testing out positions on the road. His methodology is as follows: Ride with a partner, who will act as the control. The control rider has to ride with the same equipment, same position, same tire pressure at all times. Both riders should have a well calibrated power meter, preferably two (!). The control rider's data can then be used to adjust for differences in road surface, wind, and air density. Once you factor in those control differences you can then be sure that your data is accurate. Hed believes this method is better than wind tunnel testing, since it involves real riding conditions.

Hed says Zipp just can't get their rim profiles right. Zipp's rim profiles can give zero or negative drag at certain angles, but Hed says that over all angles Hed rims perform better. Hed's contention is that Zipp publicizes the drag number from their optimal angle, while neglecting to mention that the drag number goes way up at higher yaw angles. Hed has a yaw calculator on his site: he invites you to set up an imaginary course and see how rarely you'll ride at that optimal angle.

Hed doesn't dispute Zipp's claim that the Hed3's big spokes create drag when they go through the narrow space between the fork legs. However, he contends that it's still faster.