On Wednesday, I met up with George Hincapie, his brother Rich and their marketing guy Steve Baker to see their first ever windtunnel test for Hincapie Sportswear.
On test were three new fabrics being considered for their 2011 Velocity Speedsuit, the top of the line skinsuit, which is available as stock or custom for teams…and it’s the same one George and the rest of the BMC pro squad will be racing in. They also ran baseline tests with the current fabric to see if there was any improvement at all.
Like dimples on a golf ball, patterns and texture from the weave can create high- and low-pressure zones to help air slip past and even (ever so slightly) push the rider forward. The video above shows some of the goings on at the A2 Wind Tunnel in Mooresville, NC, during the day. Jump past the break to see photos and results from the test…
In the windtunnel, they did several runs with each fabric, both at 0º and 10º to test drag straight on and with a crosswind, then average the results.
Between runs, the entire center circular part of the base was rotated between the two settings. The raw metal piece slotted onto the two bars holding the rear axle and pointed to the markings on the base, letting them get the angle exactly right each time.
From left to right, you have new, new, current and new fabrics. All four were tested and, interestingly, some of them tested with less drag at the 10º angle than straight on. The one on the right was George’s least favorite because it was too tight and the legs rode up a bit (he prefers longer legs on his for comfort, but it also maximizes the aero advantages).
All of the skinsuits on test were from the same cut and same size, so differences in fit are attributed to the way different weaves and fabrics compress. All of the team athletes get “stock” suits, then the top athletes will get some minor tweaks to the fit, length, etc. to get rid of any loose areas that might cause drag.
The 2011 model will use the same pattern as the current one.
“We’re happy with the way it fits now, so if we change anything it’ll be small tweaks to arm and leg length, etc., to keep the same basic fit and cut, just with a new fabric,” said Steve Baker, Hincapie’s marketing director. Then, in an email following the test, I got this from Steve:
“We just got the data. We are pleased that we found a faster fabric. Prototype Speedsuit #2 proved to be 0.5%-1% faster than the 2010 Velocity Speedsuit. That means that we reduced the drag of suit #2 by about 0.5%-1% just by changing the fabric. At the speeds that Pro cyclists travel in an average time trial, that savings would amount to approximately a 5 second savings over a 40K TT. In a world where victories are measured in fractions of a second, that is a fairly significant time savings.”
Here’s the screen showing the data captured for each test run. Each horizontal line represents the average for that run, and the columns tell the individual readings. The far left column is the average watts of drag, and the one before it is the wind speed. Since wind speed varied on each run, usually between 29mph and 31mph (I heard it can go up to 80mph at this facility…not 100% sure), the data is crunched to account for differences in wind speed to come up with a coefficient of drag that can be measured apples-to-apples with the other runs (third blue column to the left of the yellow columns). Click the image to enlarge and have fun with numbers…you’ll notice that the runs at 10º had less drag than the ones straight on for many of these runs.
Not sure if this is real time, but it matches up with the average wind drag numbers from the screenshot above it.
Here’s George Hincapie’s real time power output. Now, originally I was thinking that this number means he’s using about 88% of his power just fighting the wind, but there wasn’t much resistance on the roller and he wasn’t actually moving, so this math probably doesn’t hold up in the real world. But still, it shows how much power you would need just to overcome the wind at 30mph, which is a helluva lot. Maybe that’s why we normal folk can’t sustain pro-level time trial pace for more than 30 seconds while these guys bust it out for an hour. In. Sane.
Normally, there is more resistance on the rollers, according to Mike Giraud, the bicycle program director at A2, but George requested that it be set pretty light.
To measure drag, the bike is attached at the axles to metal bars that run into the basement, where all of the measurement gear is located. They’re counterbalanced so that they float perfectly freely. When the tests first start, the rider has to hold still for 45 seconds so it can calibrate. Then, they need to hold still for a few seconds again before each run to zero it out.
In the end, the measurements and numbers are balanced with comfort and fit. Here are a few questions I asked George:
TYLER: Which one did you like the best?
GEORGE: Probably the second one. The last one was too short and just not as comfortable. (note: It was also the fastest in a straight line)
TYLER: Can you feel any difference between them in terms of drag?
Following that, I overheard George and his brother Rich, who runs the company, saying that they need to decide what compromise between comfort and fit versus flat our performance once they see the data. Fortunately, it looks like suit #2 was tops in both.
Also overhead from George: “On one run, I wasn’t paying attention to my head position. Once I fixed it, BOOM, 30 watts better.”
So, kiddies, keep that head tucked.
A2 Wind Tunnel has a wide assortment of bike parts, wheels and helmets to facilitate testing your position, fit and swapping components. I overhead him saying that HED Stinger wheels are the fastest they’ve tested on their own, but the new Zipps with their specific tires are about as fast (can’t remember one way or the other) when combined with a tire.
This is his training time trial bike, not the carbon super rig he races on. That said, here’s just a bunch of photos with very little info.