Ross Tucker Does Not Understand Aerodynamics/Wind-Tunnel

rojo wrote:

I called John Kellogg today. I said, "John what did you think of the run?" He said, "My god. I've been almost exclusively cycling for the last 15 years. I think that car might have been worth 7 seconds a mile."

Then he watched some youtube clips of the Berlin marathon WR and was trying to figure out how close the car was to the runners.

Here's the bet. I'll bet anyone on here $1,000 he doesn't break 2:02:00 in Berlin. I think it's possible he does (at best 2:01:30ish) but just think people are being fooled by the final time.

One thing I want our staff to follow up with David Katz is how many extra meters does a normal marathoner run in city race due to not running the tangents. I bet it's a lot.

Henrik wrote:

First were shoes, then clock, what's next?

You're delusional if you think those shoes made any difference. Nike LOVES athletes who are so easily duped.

From scientific articles I have been able to find, a runner at around the pace they were going uses 8% less energy with no wind resistance. Running behind other runners breaks 80% of the wind. That would mean Kipchoge had a 6.4% advantage. In a regular marathon, he could probably have pacers for half the race at best so he had a 3.2% benefit. Nike is using that benefit to dupe people into believing the shoes are going to give them a 4% benefit.

I consider that FRAUD!

If you need to debate the drafting effect then it clearly a problem. Any doubt at all is not great.

Would be interested in how they measured against the painted on line. It's 30cm in from a hard edge(curb) but closer (20cm) to a flat edge like that. Also surely it's easier to run against a painted on line than next to a curb. Even just having cones on the curves would enable them to take a close line than say a taller metal barrier with spectators hanging over.

rojo wrote:

I called John Kellogg today. I said, "John what did you think of the run?" He said, "My god. I've been almost exclusively cycling for the last 15 years. I think that car might have been worth 7 seconds a mile."

Then he watched some youtube clips of the Berlin marathon WR and was trying to figure out how close the car was to the runners.

Here's the bet. I'll bet anyone on here $1,000 he doesn't break 2:02:00 in Berlin. I think it's possible he does (at best 2:01:30ish) but just think people are being fooled by the final time.

One thing I want our staff to follow up with David Katz is how many extra meters does a normal marathoner run in city race due to not running the tangents. I bet it's a lot.

oh jee john kellogg!! what he says is totally true as well! If he has experience drafting on a bike at 6 m/s, then he bikes incredibly slow.

Anyone ever dig down to more than just drafting benefits? Realize that from a neurological and mechanical standpoint that 4:35 is much different than 4:41 pace. It requires either a quicker stride frequency or an increased stride length. low 68 second quarters are much different than high 69s. Faster strides = more neurological activity. Increased stride length = more neurological activation. Force parameters at impact are different between the two speeds. There's a lot more going on from a biomechanics standpoint as well.

rojo wrote:

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One thing I want our staff to follow up with David Katz is how many extra meters does a normal marathoner run in city race due to not running the tangents. I bet it's a lot.

Katz said in another thread that the women in the Rio Olympic marathon followed the tangents better than the men. "Wind" said in a big city marathon you've got spectators hanging over fences etc preventing the shortest line from being followed. And on the Monza course there's just a painted line with cones - easier to run close to than a gutter in a big city race. My guess, 50 to 100 meters or 10 to 20 seconds saved at Monza over a big city course, maybe more.

run the simulation.

gotta love the science here, one guy exclusively cycles for x years, then throws out a number of 7 seconds being the worth of the car in drafting. sounds good but this kind of statement is even worse than Tucker's donkey work.

well, i've drafted repeat miles at that pace, and without and there is a huge difference, and i've cycled hundreds of rides in the not so distant past, however, none of this qualifies me to throw out a figure that you can your hat on.

i was involved in building some air flow devices and we made some big errors due to our primitive notions, which became readily apparent when we built and tested models.

so you learn. you know where grade 1 is and grade 5 is, and who's full of shit***

that's why, when i look at a guy like tucker and i gotta call the cops. rojo is guilty as well by association.

you have to run a simulation, with the car and the obnoxiously large sign on top, and then include the runners,

a small change in the configuration can change the drafting results significantly.

now that you're pointed in the right direction, off you go.

I think the car may have helped some with drafting but think the more obvious drafting is the bowling pin effect the pacers created for drafting. Birds use this type of formation to fly as a means of reducing wind turbulence. All good runners who race and want to win draft by letting others break the wind for them until the final kick. I don't know the exact calculations but definitely know the pacers were the draft and most people on this site are way off base on the shoes and the car.

Another giver of +1 wrote:

+1

If there was no slipstreaming advantage to be had Nike wouldn't have stuck a butt-ugly 2m x 1.5m square clock on the top of the Tesla.

You are really crappy at estimating size. You've got the area off by a factor of two.

On a thread that I started a couple of days ago, I estimated the size of the box as 50" high by 45" wide, measuring from a screen grab and knowing that the Tesla Model S is 77 inches wide. That's an area of 1.54 square meters vs. your guess of 3 square meters.

zzzz wrote:

Another giver of +1 wrote:

+1

If there was no slipstreaming advantage to be had Nike wouldn't have stuck a butt-ugly 2m x 1.5m square clock on the top of the Tesla.

You are really crappy at estimating size. You've got the area off by a factor of two.

On a thread that I started a couple of days ago, I estimated the size of the box as 50" high by 45" wide, measuring from a screen grab and knowing that the Tesla Model S is 77 inches wide. That's an area of 1.54 square meters vs. your guess of 3 square meters.

I know you are completely obnoxious on this topic as you wish to make people believe that the pace car had no effect at all on the run, but I'd like you to explain why you think the clock was only 45 inches wide.

You stated the car is 77 inches wide. Where has the ~30 inches gone here?

Nikolai wrote:

I know you are completely obnoxious on this topic as you wish to make people believe that the pace car had no effect at all on the run, but I'd like you to explain why you think the clock was only 45 inches wide.

You stated the car is 77 inches wide. Where has the ~30 inches gone here?

https://www.outsideonline.com/sites/default/files/styles/three-quarter-page-scaled-1x/public/nike-monza-italy-sub-2-marathon-half-test_h.jpg?itok=p__UqwlI

Let's get this straight. I want to know the effect of the pace car, I've already made the case that it's easy to test. I think if it has an effect, it's smaller than the effect of the running pacers. I think that there's a good chance that it has no effect at the following distance of Kipchoge. If someone did a good field test and showed an effect from the car, I would have no problem accepting that result. I would welcome it, unlike you, who have been dissuading my suggestions to do testing.

What's the deal with being against some doing some field testing? We've wasted more time in these threads than it would take to get some usable results if there was a get together with someone with a power meter.

I am not a Nike shill. I don't own any Nike shoes. I am a Kipchoge fan though. I know he got a big drafting advantage, but I think it was almost entirely from the running pacers. If the car can be shown to provide a measurable portion of the draft, I expect it to be a small fraction of the total draft benefit.

You picked a photo of a different clock. That is not from the actual event. I'll get a screen grab from the stream to show you in a different post.

Let's start with the width of the car. It's 77.3 inches wide not counting the mirrors:

Nikolai wrote:

You stated the car is 77 inches wide. Where has the ~30 inches gone here?

https://www.outsideonline.com/sites/default/files/styles/three-quarter-page-scaled-1x/public/nike-monza-italy-sub-2-marathon-half-test_h.jpg?itok=p__UqwlI

As you can see, the Tesla, like most modern cars, is not slab sided. The beltline is wide because of doors that need to pass side-impact crash tests, and stylists like wide, muscular fenders. The greenhouse tapers from bottom to top, and the clock is noticeably narrower than the roof of the Tesla.

zzzz wrote:

Nikolai wrote:

You stated the car is 77 inches wide. Where has the ~30 inches gone here?

https://www.outsideonline.com/sites/default/files/styles/three-quarter-page-scaled-1x/public/nike-monza-italy-sub-2-marathon-half-test_h.jpg?itok=p__UqwlI

http://imgur.com/a/nWWAY

As you can see, the Tesla, like most modern cars, is not slab sided. The beltline is wide because of doors that need to pass side-impact crash tests, and stylists like wide, muscular fenders. The greenhouse tapers from bottom to top, and the clock is noticeably narrower than the roof of the Tesla.

There is not 15 inches of space either side of that sign. There simply isn't. And it's the same width as the one in the image I posted.

The roof rack bars for a Tesla model S are 1.35m long. They go across the vehicle's roof. It even looks as if the clock is mounted on them.

Nikolai wrote:

zzzz wrote:http://imgur.com/a/nWWAY

As you can see, the Tesla, like most modern cars, is not slab sided. The beltline is wide because of doors that need to pass side-impact crash tests, and stylists like wide, muscular fenders. The greenhouse tapers from bottom to top, and the clock is noticeably narrower than the roof of the Tesla.

http://www.athleticsweekly.com/wp-content/uploads/2017/05/Breaking2-attempt-via-Nike-750x450.jpg

There is not 15 inches of space either side of that sign. There simply isn't. And it's the same width as the one in the image I posted.

The roof rack bars for a Tesla model S are 1.35m long. They go across the vehicle's roof. It even looks as if the clock is mounted on them.

Why are you looking an oblique view when you can use a head on view?

This time measuring from the mirrors, since they are closer to the clock than the front fenders and there is a foreshortening effect from the relatively close camera, I get 214 mm screen size for the mirrors (86.2 inches actual width, according to Tesla) and 105 mm screen size clock width. 86.2*105/214 = 42.3 inches wide for the clock. It's a bit further back than the mirrors, so rounding up to 45 inches seems reasonable. When I did my initial calculations, I used a view of the front of the Tesla from farther back, with less foreshortening and I could see the rear fenders.

Where are you getting 1.35 meters for the roof rack bar? I see the rack but not the specs for it on the Tesla page. That could be a shipping box width? The roof rack's base clearly is wider than the clock by several inches. Anyway the 1.35 meters is 53 inches. My estimate of 45 inches is 1.14 meters. The other dude's estimate was 2 meters by 1.5 meters. Why not argue with that instead?

Same for the rest, actually. I don't mind being called an egomaniac or a pseudoscience or whatever else you guys throw out, but I would like to actually discuss the relevant opinion. Some of the responses on this thread have been quite informative, those that deal with the actual models, Reynolds numbers and so forth. I've learned from them.

Not necessarily enough to change my mind re the clock, but then I've consulted pretty widely with engineers and aerodynamic experts before offering my own article, so it's not as though I'm just shooting blindly there to get attention, as some of you believe.

Of course we have room to disagree, and I'm OK with some of the personal insults you trade so freely in, but I would like those to be accompanied by some level of constructive criticism, because what I say and tweet is never meant to be the final word on an issue, but rather its first one, so the responses are important to me. These kinds of insults don't exactly advance any knowledge.

So if you disagree with any of the explained assumptions and inputs in the model that I presented after consulting experts, let me know, and we'll figure out the truth, even if I am wrong.

but Berlin will be a nice test, because I am sure they'll run the arrowhead pacer formation for as long as possible, and then we'll see what that does to overall time. I agree with Rojo (shock, horror) that 2:02:00 would be a massive surprise.

I'm yet to hear, by the way, a good explanation for the pacing paradox I explained, which is important for those who believe that human drafting trumps a car in magnitude, so I'd like to hear views on that.

Anyway, sorry you all have so much anger and ease of slander, but happy to engage with those being constructive (thanks for those who are).

Ross

ClonedDuck wrote:

Ross Tucker is an egomaniac. Drives me crazy when people take his words at 100% true. Only reason he is as well known as he is is because he feels the need to tweet about anything and everything within 30 seconds of having it happen. At the gap of 6m and going ~13-14 mph, the air falls right back behind that pace car and is left to the pacers to block.

It doesn't actually. I saw the wind tunnel models for what a car does vs having no car in front of a group of runners, and the last part of your statement is, well, an alternative fact. The air flow remains separate for a long time. Even a single bicycle 12m in front of another causes a not insignificant benefit:

Ross

Nikolai wrote:

zzzz wrote:

As you can see, the Tesla, like most modern cars, is not slab sided. The beltline is wide because of doors that need to pass side-impact crash tests, and stylists like wide, muscular fenders. The greenhouse tapers from bottom to top, and the clock is noticeably narrower than the roof of the Tesla.

There is not 15 inches of space either side of that sign. There simply isn't. And it's the same width as the one in the image I posted.

The roof rack bars for a Tesla model S are 1.35m long. They go across the vehicle's roof. It even looks as if the clock is mounted on them.

Here's a top view of the Tesla showing the muscular fenders and tapering greenhouse that I mentioned earlier:

Based on this top view of the Tesla Model S, the distance between the top of the left side and top of the right side doors is about 48" (137 mm screen width of the actual 86.2 inch wide mirrors, 77 mm screen width of the roof at the clock location 86.2*77/137). The base of the roof rack is 48" inches max, and extends beyond the clock by a bit. My first estimate of 45 inches looks good.

The paid Nike trolls have been flooding the board all week. They're trying to downplay any effect of the Tesla draft so the focus is on shoes and nutrition.

Ross, I haven't seen you discuss the actual distance run by Kip vs. the actual distance run by most racers in a standard marathon. In other words, he hit perfect tangents, whereas in races most don't. I estimate this adds 200m to most races. Your thoughts?

Former intern wrote:

The paid Nike trolls have been flooding the board all week. They're trying to downplay any effect of the Tesla draft so the focus is on shoes and nutrition.

I'm not a Nike troll. They make sh!t products that they don't stand behind. I once sent back a pair of Nike Zoom Trail S to their warranty department with less than a week's wear on them and still in clean condition. The uppers had 3 inch long tears at the forefoot flex points from a poor upper fabric choice. They sent the shoes back to me with an insulting letter. A total waste of $100+ and whatever it cost in shipping to send it back to them.