I have a perfect hill to run an aero comparo. Same take off point and using top speed as indicator. Same outerwear, helmet.

Here's some results:

Top speed

1. Road bike: 46.84 km/h (tucked in legs, arms and chest lowered)
2. Argon E118 slammed bars: 48.17 km/h
3. Audi A8 (coast in "N"): 49.5 km/h
4. Guru w/distance setup: TBA


I didn't think the car would be fastest. The goal of the test is to see the difference between the Argon setup and the Guru, for the purposes of a sprint race.

Different days, different wind, different air pressure and humidity pretty much invalidates the comparison.

But if you can "tell" the E118 is faster anyway, then you don't need test results :)

duncan wrote:

People actually buy the Audi A8?!?

Haha they don't - that is what makes the A8 such a bargain per ton- of aluminum. Especially in Canada where Toyotas rule the roost because they are cheap to run and the A8 with it's 60 computers on board scares the living @^#& out of any out-of-warranty car shopper. I wrote about in on my Garage9.com twitter:

" $7000 usd gets you: a tri-bike that makes you 30s faster, 1 week vacation for 2, 1yr kids tuition, or this Audi A8".

https://twitter.com/...s/662434903250722816

I've always had an Audi sedan in the stable as a winter car: 5000S, the V8 for years, now this A8.

OK back to bike tests I ran the Guru down the hill this morning. Two things, the Conti GP Classic tires are no race tubulars, the frame is bigger, position a little higher and a slight head breeze the speed matched bang on the road bike test. But I could tell this setup is slower than the Argon with low bars, race tubulars, Zipp 808 with new hub.

I think I'll race the E118 in the sprint.

Top speed

1. Road bike: 46.84 km/h (tucked in legs, arms and chest lowered)
2. Argon E118 slammed bars: 48.17 km/h
3. Audi A8 (coast in "N"): 49.5 km/h
4. Guru w/distance setup: 46.84 into a slight headwind, HED 6/9 Conti GP classics.

Guru Bike run: /quote]



Here is suggestion, put Audi in D press pedal on the right, and race it, instead of Guru.... You will win 100%.

You almost sound like you work for Argon aero department and just share your firm 2017 aero numbers. Is your GPS at list capturing data every fixed amount of time, what is that number? What GPS are you using?

I have nothing against Argon or Guru or Audi, but your test in current form is sketchy at best :)

TomTom multisport watch. it's within or better than 1M accuracy. I've paced it out and also timed swim sprints to 50M-100M on open water in our lake (watch in cap). I am faster in the lake than a pool and it has to do with the water. No two pools are alike either, that is why comparing times internationally (as swimmers do) is sketchy at best, but that is another discussion.

The aero tests were very repeatable & each run within a surprisingly tight margin (I have to look around 0.25-.5 km/h). Wobbles slow you down. So if I run and am wobbling around a bit too much, I will set the slower top speed. Head lifting catches air but for each run you need a say 1/2 doz to keep it straight down the lane. Just working the terms of the drag equation.

I've raced both bikes so holding position is not too much of a issue. Neck doesn't like it to low tho.

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All your doing is proving the total drag (rolling resistance, plus aero drag) to weight ratio.

The Audi will also have the drag for the transfer case, 2 differentials and the transmission... on top of the 4 wheel bearings. Putting a car in neutral only decouples input gear set from he output gearset or the equivalent, depending on type of tranny. If a manual, pushing in the clutch while from the transmission. Which is slightly less drag than just pushing in the clutch on a manual, since when in neutral, the engine will neutralize drag on 1/2 of the transmission. With clutch in, the wheel have to overcome all of the drag.

The brake rotors also drag a small amount.


... please remove all 4 half shafts and try again. Or alternately, you can drop in out of a airplane nose first and measure terminal velocity. that eliminates rolling resistance and drivetrain losses.