It's Wind Tunnel Time!
by Dan Empfield
January 20, 2000 (www.slowtwitch.com)
It It drives John Cobb crazy. "Steve Hed is just too damn nice," he says with a tinge of exasperation. "Here is the guy who has spent more money, invested more time, thought more deeply, and worked more diligently than anybody else in this business. He was at third base on wheel design before anybody else even got to the plate. And he's more than happy to tell any competitor anything they want to know about how to build wheels, because that's the kind of guy he is."
The "anybody" Cobb referred to is no "nobody," he is Shimano's national sales manager and several-time national cycling road champion Wayne Stetina. Hed went so far as to build up wheels himself with both Shimano and Rolf spoke patterns to demonstrate for Stetina exactly how Shimano's new wheels reacted in the wind tunnel with deeper and deeper rim sections, and how a Rolf-type spoke pattern would likewise fare. Stetina came away with invaluable information, according to Cobb, who scratched his head and wondered how long it will take Shimano to make a wheel the equivalent of that which Hed now makes. "Steve told Shimano how to build a fast wheel. Whether they will or not I don't know, but if they don't it's not because they don't now know how."
Not that Cobb would normally care, because America's top seller of high-tech wheels will sell anybody whatever they want and is among the biggest sellers of Zipp, Corima, and Mavic wheels as well as being Hed's No. 1 dealer. But Cobb built his business off of a symbiotic relationship between Hed-the-wheel-builder and Cobb-the-wind-tunnel-engineer.
Every January Hed and Cobb make their annual migration to the wind tunnel at Texas A&M University. They've been there every year during the decade of the '90s and now are starting another decade testing wheels, frames, rider positions--everything that affects the aerodynamics of rider and bike.
Last January Lance Armstrong and a few of his U.S. Postal Service teammates were in the tunnel. It wasn't the first time Lance had been there--he'd been working with Hed and Cobb since he was a triathlete, and never forgot where to go when work on his time-trialing form was needed. Armstrong also used the opportunity to test his new Giro helmet, which resulted in a redesign of its now-famous shape.
It's not that Steve Hed is not fiercely competitive. He just has a tendency to view the wind tunnel as "open platform," almost an industry symposium. He more or less sheds his role as businessman just for that week and, figuratively speaking, dons the lab coat. Not that just anybody in the industry is invited. But those like Stetina, who have earned Hed's respect, are welcome.
What were the results of this year's tests? For starters, the reaffirmation, according to Hed, that, "Deeps in the front are the way to go for the people who can handle that much surface area." Hed's new Stinger, which is finally (knock on wood) ready for shipment--at least in 700c--is by far the lightest wheel in his lineup, and will be the most comfortable. But it will not be quite as aerodynamic as either the Hed3 or the Deep, each of which has more surface area, and in that order. The Hed3, Hed's trispoke, tested second best of his wheels, and the Deep is the best of all non-discs. Nothing, though, has ever beaten a disc in the tunnel, notwithstanding claims to the contrary by some wheel-makers.
Hed also mocked up wheels with Rolf-like and Shimano-like spoke patterns. "It doesn't make much difference at all how you spoke up the wheel," he said. "Our tests prove out what we've always thought, that the rim is what makes the difference in a wheel with standard metal bladed spokes. Personally, a few spokes more or less isn't going to make hardly any difference--if I was racing I'd want a wheel where you can still ride it if a spoke breaks."
Shimano's Stetina (left, talking to Hed, to his right) went to the tunnel in the middle of 1999 with Cobb and returned in January for more testing. Part of his interest, according to Hed and Cobb, was in rim profile, and part of it was in the tire/rim interface. Stetina brought down a variety of tires to see how they'd work on our wheels.
"Tire shapes and brands make a big difference," Hed said. "You can make the best wheel slow by putting the wrong tires on it. Finding a tire that fits the general profile of the rim is huge. Those tires whose tread had an abrupt junction with the casing were really bad; the tread's interface with the rest of the tire underneath has to be smooth and seamless if low drag is what you want."
Hed also stressed that one wheel isn't extremely aerodynamic compared to others that were out there. "When we first started testing, our good aero wheels would just murder a standard, box-section aluminum Mavic rim. But it's really hard to be a lot better than another wheel company anymore, if the other company is legitimately trying to improve their product every year. It's the same with bikes--all the guys who've paid attention to their aerodynamics, all their stuff has gotten better."
Bikes were tested as well--Kestrel, Softride, Javelin, and the new Hotta Perimeter. "The Hotta did very well considering the legal limitations it tries to maintain; it is a road race bike and is probably the most aero UCI-legal bike out there," Hed said.
Kestrel and Softride did well also, with Softride's Rocketwing again testing very well. "Softrides are always good in the tunnel," he said.
Whereas Hed and Cobb usually have a gaggle of elite triathletes and road race athletes in the tunnel, this year they focused on Clydesdales. They wanted to see whether the bigger athletes faced the same issues as the smaller elites. "Turns out," said Cobb, "we had a guy who was 6'6" and 240 pounds, and he had 10.2 pounds of drag going into the tunnel. We worked on him a bit, and he had 7.8 pounds coming out. That's about as low as we can get these big guys. We had a couple who were 5'10" and weighed the same, and they also generated about 7.8 pounds of drag. These shorter guys are so wide, we could only get them about a half a pound better."
Years ago Cobb's language used to be liberally sprinkled with readings in pounds of drag, and occasional interpolations of what that would mean in time savings. Now, you hear him talking much more often about watts.
"Watts are easy to understand," Cobb said. "It can be confusing when we mix time and watts and drag. But when we take the drag reduction of a good wheel and convert it to watts, and the watts it takes to turn the wheel at speed in the tunnel, then we can say, 'You're going to use 350 watts to go such and such a speed with your bad position and standard wheels; we can save you 75 watts with your good position and good wheels.' They understand that."
One reason Hed doesn't seem to mind telling all to those like Stetina is that he is sure he's got a better wheel in the hopper. But producing a better wheel every year or two isn't the easy task it used to be. More wheel companies with bigger dollars behind them are working on wheels with a fury. The first big company to jump into the wheel market was Campagnolo, followed by Mavic. But then the really big companies started to get in, like Trek, and finally now THE company, Shimano. Does the small operation in White Bear Lake, Minn., which popularized lenticular discs, deep carbon rims, and the aerodynamic ellipse, have another trick up its sleeve?
Perhaps. But that conjures another mild irritant to Hedís friend Cobb. "Right when Steve finally gets a wheel right, and gets it marketed, and just when the market gets to understanding that this is a fast wheel, he brings out another one. He can't just ride one horse for a couple of years. He's always bringing out something better. So his band of loyal customers are sometimes scared off from buying, for fear there's something else better right around the corner."
Finally, one anxiously awaited wheel seems to be here, at least in 700c. Hed's Stinger has proven an extremely difficult wheel to build, and its introduction keeps getting pushed back. But it is an extremely lightweight deep dish wheel that is the best combination yet, Hed believes, of light weight and an aerodynamic shape in a deep dish wheel. But most of his customers will probably choose the Deeps--for ultimate front wheel aero performance--or Hed3ís as an all-around, hassle-free, reasonbly priced lightweight wheel.
Stetina doesn't see himself trying to out-aero any wheels made by Hed. Road-worthiness is what Shimano is looking for. "We want our wheels to perform well for triathletes regardless of the course they choose. We want to make reasonably aerodynamic wheels that are quite lightweight and descend, corner and climb well, the kind of performance you'd need on a course like Nice."
It would also be difficult for Shimano's rim maker, Araya, to make aluminum rims that have anything close to the cross-sectional area of a Hed rim because of aluminum's weight and the engineering difficulty of attaching the spokes in the side of the rim. Just the same, Cobb wishes that Hed was not quite so given to generosity.