It turns out the Campy Boras are actually quite aero (Tour Magazine latest aero hoops test)

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PrimO
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by PrimO

spartan wrote:yes . read the article last night. buy it.

zipp 404 - 222 watts
zipp 303 - 225 watts
zipp 202 - 226.8 watts

now for the so called un-aero campy wheels

bora 50 one - 224.7 watts
quattro carbon - 226.4 watts

cheap Chinese enve knockoffs front 50/rear 60 - 223.9

btw they mavic/campy/zipp/newer dt wheels survived the alpine brake torture test. the chinese rims melted.

overpriced enve wheels were not tested .. i wonder why :twisted:


For the stupid among us, what do those wattage figures actually represent, ie is the lower figure better or worse? I don't think Tour magazine is available here in Europe so cant buy/read it for myself.

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fa63
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by fa63

Lower the better; it means you need less power to maintain a given speed.


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by Weenie


Marin
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by Marin

spartan wrote:btw they mavic/campy/zipp/newer dt wheels survived the alpine brake torture test. the chinese rims melted.


Oh, and DT Swiss and Reynolds too.

The test is exceedingly hard, Tour Magazine melted the alu cores of Shimano brake rotors in a similar test, something that never occurs in the real world.

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mpulsiv
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by mpulsiv

I'm a firm believer that it's all about rim profile. Even Specialized admitted that their new Roval 32 (1280 grams) is faster than notorious Roval 40 wheels but wait, there's no more! New Roval 32 provide near identical performance to the CLX 60 wheels when riding in a slight cross-wind. 

Tour Magazine (3/2016 issue) tested 15 bikes with stock wheels next to Zipp 404 Firestrike. Giant SLR 1 30mm wheels were slower by ~10 seconds on 100km course with 2000 meter of elevation, 4+ hour ride. In contrast other stock wheels were ~60 seconds slower.
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
:arrow: OCD = Obsessive Cycling Disorder

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F45
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by F45

I've never seen shallower rims keep pace with deeper ones in the tests or white papers that Flow, Zipp, or Trek release. I'm sure a fortuitous matching of rim to tire profile helps.

PrimO
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by PrimO

mis-post.

reery
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by reery

Can someone explain what the differnece in average speed would be if I'm riding around 32 kph in one hour at 200 watts. Now exchanged my bike which has 235 watts @ 45 kph with an aero bike and deep section wheels (210 watts @ 45 kph)... what averaged speed would I get at my 200 watts?

caddis
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by caddis

Don't really understand your question, but NO aerobike in the world will give anyone 45 kph with 235 watts...

mimason
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by mimason

caddis wrote:Don't really understand your question, but NO aerobike in the world will give anyone 45 kph with 235 watts...



It can be done in a tailwind tunnel. :beerchug:

DamonRinard
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by DamonRinard

caddis wrote:... 45 kph with 235 watts...


Could it be they're referring only to air power, not total power (so no Crr, etc.)?
And it might be only with legs, not the rest of the body?
Damon Rinard
Engineering Manager, Road Bikes
Cycling Sports Group, Cannondale
Ex-Kestrel, ex-Velomax, ex-Trek, ex-Cervelo

helldiver
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by helldiver

That's correct, no UCI legal aero bike will be so effective to enable 45km/h at 235W (assuming zero wind conditions and level road). I remember one test when they tested effects of various aero equipment and ride positions, they went from 450W@45km/h (normal road bike, loose jersey, no aero helmet, upright position riding on hoods) to 280W@45km/h (time-trial bike and everything from shoes to helmet aero optimised). That said, there are HPVs which are much more effective and enable you to ride with 116W@45km/h (or 185w@60km/h) but they don't resemble upright bikes at all :D .

reery
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by reery

caddis wrote:Don't really understand your question, but NO aerobike in the world will give anyone 45 kph with 235 watts...


The assumption 235 watts at 45 kph is from the Tour magazine. Thats what they've tested. An aero bike with ds wheels would have around 210 watts. Thats 25 watts difference. My question would therefor be, how much faster would I be if I can average 32 kph@200 watts on my non-aero bike with the switch to an aero bike.

According to their testing they save 10% but how can I translate these test results to our real world with speeds around 30-35 kph?

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mpulsiv
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by mpulsiv

F45 wrote:I've never seen shallower rims keep pace with deeper ones in the tests or white papers that Flow, Zipp, or Trek release. I'm sure a fortuitous matching of rim to tire profile helps.


Giant TCR stock wheels 30mm deep. Very close performance next to Zipp 404 Firestrike.
Fuji SL stock wheels 32mm deep. Far from aero!

Am I missing something?

Image
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
:arrow: OCD = Obsessive Cycling Disorder

DamonRinard
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by DamonRinard

I'm visual, so I use graphs.

Start with Figure 3 here:

http://sheldonbrown.com/rinard/aero/formulas.htm

(0) Plot Tour's power savings at 45 km/h. This is the red line at the upper right. (This is the part I forgot when I first posted.)

Image

(1) Locate your current speed and power on the graph. That's the orange circle at 32 kph and 200W.

(2) Then drop the power in proportion to Tour's measured savings. Follow the yellow line down about 1/3 of the way towards the "Aero bike" curve.

(3) Since you insist on still pedaling at 200W ;-) , follow the diagonal green line up the invisible curve (this is the curve of your your new, more aero bike, in between "Racing bike" and "Aero bike" and roughly parallel).

(4) When you reach 200W, you arrive at your new point, the blue circle.

(5) Follow the blue line down to read your new speed, ~33 km/h.

Cheers,
Damon
Last edited by DamonRinard on Sun Aug 14, 2016 5:01 pm, edited 3 times in total.
Damon Rinard
Engineering Manager, Road Bikes
Cycling Sports Group, Cannondale
Ex-Kestrel, ex-Velomax, ex-Trek, ex-Cervelo

by Weenie


DamonRinard
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by DamonRinard

mpulsiv wrote:...Am I missing something?


Yes. Aerodynamics, like bike racing, is 3D. Rim depth is just one dimension.
Damon Rinard
Engineering Manager, Road Bikes
Cycling Sports Group, Cannondale
Ex-Kestrel, ex-Velomax, ex-Trek, ex-Cervelo

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