This week, the Al33 and a number of other rims will be tested in the A2 wind tunnel in North Carolina. We aren’t paying for it, it isn’t our test, but we agitated for it to happen, facilitated all of the arrangements, and designed the test.
. . .
The test will use a 2017 model Zipp Firecrest 303 as a baseline. Tested wheels will be a HED Belgium+, a Kinlin XR31T, the Al33, and a Flo30. All wheels are 20h rims built with CX Rays and standardized hubs, except for the 303 which is of course an 18h wheel which uses Zipp’s own hub and CX Sprint spokes.
I’m interested to see how this test pans out. The 303 and other modern wheels of a similar depth are truly the “jack of all trades” wheelset especially if you throw in a disc cover.
I’ve had a set of “Fairwheel Phalanx” wheels for a while now, which is a set of XR31T’s build on DT350s + Sapim Laser. It’s a really nice rim, I’ve been exceptionally pleased. (<$450) Good to see it’s also pretty darn aero. Although the spec wheel from Fairwheel isn’t identical to the tested wheel obviously.
I’m glad that I built up my front using XR-31 last year. Truth is, difference btwn these new alloy 30mm rims and 60mm tubular stalwarts (e.g. Stinger 6) is a few watts at most, and the former has good braking performances.
I especially appreciate the following from the blog entry
Have reasonable expectations. In the Tour Magazin test I referenced earlier (seriously, download it), the difference between best and worst was 13 watts. That’s 40ish seconds in a 40k TT at 30mph between a Mavic Ksyrium and a 404 and DT Swiss 65, which were the fastest wheels in the test. That’s about .4mph, worst to first. Anyone telling you you’re going to go 2 or even 1mph faster by just switching to more aero wheels is selling you a load of crap
granted, i’m not sure if that’s front wheel only, or front + rear (toss in another 5-6W), but the fact remains that wheels only look nice, but past a certain point doesn’t give as much return
I’m glad that I built up my front using XR-31 last year. Truth is, difference btwn these new alloy 30mm rims and 60mm tubular stalwarts (e.g. Stinger 6) is a few watts at most, and the former has good braking performances.
I especially appreciate the following from the blog entry
Have reasonable expectations. In the Tour Magazin test I referenced earlier (seriously, download it), the difference between best and worst was 13 watts. That’s 40ish seconds in a 40k TT at 30mph between a Mavic Ksyrium and a 404 and DT Swiss 65, which were the fastest wheels in the test. That’s about .4mph, worst to first. Anyone telling you you’re going to go 2 or even 1mph faster by just switching to more aero wheels is selling you a load of crap
granted, i’m not sure if that’s front wheel only, or front + rear (toss in another 5-6W), but the fact remains that wheels only look nice, but past a certain point doesn’t give as much return
I’m reminded of an aero wheel test from the Augst 2016 issue of the German magazine “Procycling” that I stumbled upon while surfing the net for wheel test data. It was a bit of a pain to translate the article a few paragraphs at a time, but I did and the results were quite fascinating. They put a pro cyclist on a velodrome with various wheel sets and measured the power output it took to maintain 40 and 45kph.
No Zipps were used in the test, but the Roval C64s kind of served as the established high performance bench mark. . For curiosities sake, they included one affordable medium depth (32mm) alloy wheel, the DT Swiss R32 Spline, which I’ve seen online for as low as ~$360 a set, shipped. At 40 kph, the difference from the DT Swiss to the Rovals was about 6 and a half watts. I’m more like a 35kph guy, so for me I’m guessing it would be more like 4-5 watts difference. FWIW, the Swiss Side Hadron 625s ended up testing the best, a fraction of a watt better than than the Rovals at both 40 and 45kph.
A velodrome test won’t tell you much about high yaw situations, but, because of the turns, it’s more than a zero yaw test. They claimed the effective yaw varied from 0-5*. I was really considering spending $1200ish for some HEDs or Hadrons, convinced they’d save me a bucket of time. That test changed my mind. Now I know there’s lower hanging fruit on my aero tree.
Shock results just in from the wind tunnel!!! “Paying customer’s product goes better than anticipated!!”
Colour me sceptical but I think the most salient point is that the difference between wheels in terms of aerodynamics aren’t as great as what the “market leaders” would have us believe. Another shocking discovery.
Flo is a MUCH better A2 customer than any entity involved in yesterday’s test, and for what it’s worth we weren’t the paying customer. A2 wouldn’t have had any idea which wheel to influence yesterday if they were inclined to do so. But just to counterpoint skepticism, if A2 were inclined to fudge results, don’t you think the Flo 30 would have done “better”? That result has the potential to piss off a customer who does a lot of work at A2.
As to your second point, yes, I agree wholeheartedly. With every hair on my head, and there are fortunately still tons of them.
Dang, I just bought Flo 30’s over Kinlin 31XRt for the supposed aero property, giving up 80g each rim. I could have lighter weight and better aero properties!
Shock results just in from the wind tunnel!!! “Paying customer’s product goes better than anticipated!!”
Colour me sceptical but I think the most salient point is that the difference between wheels in terms of aerodynamics aren’t as great as what the “market leaders” would have us believe. Another shocking discovery.
Been saying this stuff for years, that there is so much marketing bullshit, but this is slowtwitch…
Interesting that the Flo30 seems to stall so badly after 15 degrees in this test. Flo’s data from when they were testing their new wheels shows a slight decrease in drag all the way out to 20 degrees.
The test will use a 2017 model Zipp Firecrest 303 as a baseline. Tested wheels will be a HED Belgium+, a Kinlin XR31T, the Al33, and a Flo30. All wheels are 20h rims built with CX Rays and standardized hubs, except for the 303 which is of course an 18h wheel which uses Zipp’s own hub and CX Sprint spokes.
November doesn’t make that rim but they seem to be the first to get their hands on them for production.
The take away I get from that graph, when you factor in the “AOA distribution,” is that the Kinlin XR31T looks like the clear winner.
I agree that this test shows the Kinlin looking good at low yaw angles, where things matter. I’ll also mention that the FLO 30 was designed in 2012 and is our only rim that has not been designed with our new low yaw algorithm. I’ve said for years that the only way to do a real tunnel comparison test is to get all manufacturers in the same tunnel for a “take your best shot” type of test. Personally, I think that would be cool, but I don’t think many brands would sign up for that.
