cslone

Now, as Steve Hed is reported as saying he would like to see independent tunnels test these. But if these wheels are even close to what this graph shows, that is huge. Is HED going to be the new Zipp bandwagon?

Graphs of the new wheels from HED, the Stinger 6 and Stinger 9. I'm hesitant to believe 0(or even negative drag), but man if this is true a Stinger 9 rear and Stinger 6 front would be an awesome RR setup. Dual 9's would rip a hole in the time continuum.

dstrong 

I don't understand what that means but it's a pretty graph.

carlfreddy

What are the HEDs being compared too in that test?

DrPete 

since zipp is the only 108mm rim out there, my guess is the Zipp 808 and 1080.

brianappleby

wow...so zipp's wind tunnel tests prove that zipp's wheels are the fastest, but HED's wind tunnel test proves that HED's wheels are the fastest.

OMG!

Duke of Kent

Now if Bontrager would just add a 90mm rim to their arsenal, using the HED rim shape (already use if for the Aeolus 5.0 and 6.5 wheelsets), and my team would spring for some new race wheels for the boys, I'd be a happy camper.

BananaTugger

There's no mention of speed anywhere.

They might have tested the gear at 10 KM/H for all we know.

FlashBazbo

But they are only amazing at a 12.5* yaw angle. (Now let's graph the rolling resistance of the tire/wheel combination with it cocked at a 12.5* yaw angle!)

I am amazed at how much drag they have going straight compared to drag at a 25.0* yaw angle. Of course, total drag + rolling resistance goes rapidly off the scale with increasing yaw angle. The amazing 12.5* yaw angle/drag stats are utterly meaningless.

ElJamoquio

They claim a min drag of 110 grams on their website for the Stinger 90. Don't know what this 9 is, but that's a pretty big improvement.

Flatballer

If you can manage to find a cross-wind that matches up with your speed to give you a 12.5* apparent wind, your wheels will make 0 drag. Pretty cool. I don't feel like doing the math to figure out which combos of wind angle/speed and your speed would give you that though.

Theoretically, there would be a point where slowing down would actually make you faster.

Flatballer

You don't understand what yaw angle is, apparently. The yaw angle is the combination of the speed and angle of the wind with the speed and angle of the bike. It's the same thing as the "apparent" wind angle in sailing.

Do you really think their aeronautical engineers are stupid enough to make a meaningless graph?

sac02

I think you misunderstand what yaw angle means in this graph, though possibly not entirely your fault. I believe the graph would be more accurately labeled "incident wind angle".

+1 to wanting to know what the other two wheels tested are, and wishing for an independent test.

Mac

DrPete 

Both Zipp and Blackwell also say that most real-world conditions give a yaw angle of 7-15 degrees, so that's why their designs are made to hit a sweet spot at those yaw angles.

Fat Boy

4.4mph crosswind if you're going 20mph ground speed. A completely reasonable set of circumstances.

Slowing down wouldn't make you faster....it'd make you more efficient.

The zero drag or negative drag numbers that wheel manufactures come up with drive me nuts. It's like some claiming they can make lift with a piece of plywood. Well, yah, you actually can, but the drag is so high that what you've accomplished is meaningless. It's the same deal here. You can reduce drag to something very small, but your side force numbers get so high that you couldn't control the damn bike. Again, not very useful. When you put a bike, rider, and spinning wheel into the equation it also changes things massively. They rarely get that deep into it.

Some manufacturers claims would make a politician blush.

cslone

But it is still faster between 5 and 25 degrees, which is most of your riding.

cslone

One example is 26.2mph with an 11mph wind.

cslone

That's the point thougn in the 60mm. That is not a deep wheel that almost anyone could control, but it has the same drag as a 90mm+ wheel.

And although I believe about anything that comes from Steve Hed, I would still like to see some independent tests too.

DrPete 

Actually, all of Zipp's time savings claims are based on Fabian Cancellara on his Cervelo P3C averaging 300 watts. I'm sure they do wheel-only stuff too, but the numbers they advertise in their "Real Aero Advantage" ad are based on wheel, bike, and a pedaling rider.

Fat Boy

I was specifically talking about the claim that their disc wheels make thrust. How can that possibly be with a spinning wheel, bike and pedaling rider? It just seems too far-fetched to me.

DrPete 

Sailboats can sail into the wind... I'm not saying it's 100% true, but they also only advertise the negative drag at 15 degrees of yaw. Who knows--I certainly don't. I'd love to have the $$$$ to rock a powertap-equipped Sub 9 someday, though.

cslone

Won't pretty much any disc "create thrust" in the right yaw? i.e. a sail?

BananaTugger

Almost all disc wheels are symmetrical, so no, it won't.

DrPete 

Wind tends not to hit both sides of the wheel equally.

BananaTugger

Same with airplane wings, but they have to be asymmetrical for them to create any lift.

Bernoulli Effect.

Pedaleur

No they don't.

Trust me.