100 MPH (160 km/hr) on 1-hp/746 Watts

[aerohead]

If you didn't catch Delft University of Technology's Velox 2 September IHPVA triumph at Battle Mountain,Nevada you should check it out.
They got to 83.1 mph at elevation,which equates to 100 MPH at sea level.
Their rider,Sebastian was exerting 800-Watts of power.Subtracting a smidgeon for the roller chain losses gives a road load of about 1-hp.
Aerodynamics?,we don't need no stinkin' aerodynamics.
here's a pic:
By the way,be thinking about synthetic vision from now on.It's gaining traction.

[NachtRitter]

Always surprises me when they put the camera up on a stalk like that rather than having a transparent section of the nose with the camera behind it... Guess it's not all that big a deal aerodynamically...

[niky]

I'd like to see them actually hit 100 mph at sea level.

But that's insane... does the man have Martian lungs?

[California98Civic]

Here is the pic aero head linked to:

[kennybobby]

Looks like they used the template but are running it backwards? They mentioned having an aerodynamic issue which prevented reaching the calculated top speed.

Human Power Team Delft & Amsterdam

[jamesqf]

Originally Posted by aerohead

They got to 83.1 mph at elevation,which equates to 100 MPH at sea level.

I'd really like to see the rationale for that claim. Since air density (& hence resistance) is higher at sea level than at Battle Mountain's moderate elevation (~4500 ft), it's likely that the top speed at sea level would have been less. (It's certainly true for airplanes...)

It might be thought that the pedaler would output less power due to thinner air, but that's not the case, particularly if he spent a few days training at similar altitudes. The body adapts - and a mere 4500 ft elevation isn't really enough to matter much, anyhow.

[aerohead]

Originally Posted by kennybobby

Looks like they used the template but are running it backwards? They mentioned having an aerodynamic issue which prevented reaching the calculated top speed.

Human Power Team Delft & Amsterdam

As Sebastiaan exceeded 500-Watts of power output,he was stressing the body structure enough to deform its shape,hence altering the airflow/CdA.
This is in the realm of Kelly Johnson's Skunk Works engineering.Making it just strong enough for the task.

[RedDevil]

The reason they went there is the lower resistance at altitude.
Of course the rider has less oxygen too and cannot get as much oxygen an will produce slightly less power, but these guys are professional sprinters; one of the other contestants was Theo Bos, multiple sprint world champion(*)
They use their white muscle tissue and get their oxygen after the race.

Put two in a tandem bicycle, then maybe 100 mph is possible.

The camera on the stalk was lighter than one in the nose with a long cable to the screen.

(*) I have to take that back.
It was not Theo but rather his brother Jan Bos that I saw, a former sprint speed skating world champion competing for one of the other teams. Many skaters use cycling for training and some excel in both disciplines. A pur sang sprinter no less.

[aerohead]

Originally Posted by kennybobby

Looks like they used the template but are running it backwards? They mentioned having an aerodynamic issue which prevented reaching the calculated top speed.

Human Power Team Delft & Amsterdam

To me it's more of an extremely narrow elliptical fuselage morphing to a wing section trailing edge.Like a tuna.
Craig Vetter spoke of 'shrink-wrapping' the body around the necessary mechanical tidbits,allowing only enough to contain things,minimizing frontal area while preventing separation.
At GOOGLE IMAGES you can see a CFD image of the Velox 2 in VSAERO.
Here's a sliced open shot
Here's the CFD

[aerohead]

Originally Posted by jamesqf

I'd really like to see the rationale for that claim. Since air density (& hence resistance) is higher at sea level than at Battle Mountain's moderate elevation (~4500 ft), it's likely that the top speed at sea level would have been less. (It's certainly true for airplanes...)

It might be thought that the pedaler would output less power due to thinner air, but that's not the case, particularly if he spent a few days training at similar altitudes. The body adapts - and a mere 4500 ft elevation isn't really enough to matter much, anyhow.

When I first went out there the HPA folks told me that it was a matter of metabolic equivalency.They expected muscle output to suffer from the lower oxygen transport and factored in the density difference with respect to drag issues.
At essentially the same elevation,east of them at Bonneville,my truck was down to 124 bhp vs 150 bhp at sea level due to the density altitude.I'd have about a 12% reduction in drag due to the thinner air,and if the salt could have produced a similar rolling force coefficient as pavement (not the case),my top speed should have been identical to sea level.
The temp and humidity is probably kinder to the riders at Battle Mountain as it might be at Daytona Beach,or out on California Highway-1 near Paradise Cove/Zuma Beach.
They're enclosed in the shells with virtually zero ventilation.Worse than NASCAR.
I felt,and feel that they've done their homework very well and have a high confidence in their numbers.
Watching Sam Whittingham coming at me at over 81 mph was a transformational experience to say the least.