Have the actual issue in my hands. They both got the same grade: 1.0 (the best).

Nice. I wish Tour was available on android.

i thought the venge turned out to be slower than the s3

It's not on the tour-qtr yet. It's just on the February issue of Tour print magazine which came out Tuesday. There were multiple ones which were very close:


The test method sounded pretty good so I'd say it's legit.

Was it the same one they used previously that omitted the cable housings? If so, that's going to "hamstring" frames with hidden cable entries vs. ones that don't have that...

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http://bikeblather.blogspot.com/

know enough german to translate the testing protocol?

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Wow, I have an S5 and spent alot of time with the scott foil. I have a hard time to believe a foil or any bike beats an s5 at 0 yaw.

Tom & Jack: I'll take some time later today to translate it. Gotta do some work now :)

I'm quite impressed with Felts AR1 results considering that frame is years older than the Venge or S5.

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"One Line Robert"

I seem to recall the S3 doing relatively poorly at 0 yaw in the last Tour aero test. Hmmmm....

Yeah, it's a garbage bike...stay away from it. Of course you might note the Venge line on that chart is in pink, so...

Well, something changed in the analysis of the results because the power bar-chart is slightly lower (within the error bars though) for the Felt AR0 tested previously (AR0 and AR1 are identical aerodynamically, right?) while the previous value for the S3 is lower than for the S5 even though it's pretty clear that S3 CdA curve isn't as good as the S5 above 5d of yaw.

The AR0 and AR1 CdA curves seem to match pretty well between the tests though...which then begs the question again of why the AR1 is shown to be slightly lower power than the AR0.

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http://bikeblather.blogspot.com/

..and I wonder why the VN test showed the Felt AR1 as slower than an S3 (across the board) when both were tested with the same wheels?



Oh...and the asymmetries shown above also points out that Tour's testing is somewhat incomplete since they appear to have only tested in one yaw direction...tsk, tsk ;-)

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http://bikeblather.blogspot.com/

Not really sure. You guys seem to have the graphs/drag stuff dialed. I am not smart enough to understand much of it. I just got a Venge Pro DA. Best bike I have ever ridden! The wheels are ok, but the bike is a freaking rocket ship!!!! Just my 2 pennies :).

they may have tested in both and averaged

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Then why is the X-axis labled in negative degrees? ;-)

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http://bikeblather.blogspot.com/

Just reading the entire article, the most important points + the test protocol:
- This time the cable housings were kept on and an additional measurement at 15 deg. yaw was done (mentioned within the article)
- The weight for the final grad of the frame was 20% of the aerodynamic grade. (not really important for us here, so just ignore the grades)
- There are a lot more tables with STW, stiffness, weight etc. (buy tour qtr if you need it all I suppose)
- Cervelo asked Tour to do the aero test WITH the aero bottle as the frame was design that way.
- Tour says the bottle was aerodynamically neutral. So no better but also no worse. They had it in the lower position in which case u can't mount a sec. bottle
- All frames had a pair of Mavic Cosmic Carbone SLR + Conti GP 4000S
- The measurements error was 1% (displayed with the error bars)

Test protocol:
- They mounted a dummy which they developed themselves
- The exact positioning of the dummy was done with 5 positioning lasers (whatever that means, I assume 5 reference points on the dummy) to assure the exact same position.
- Measurements were done with rotating wheels at 45 km/h
- Yaws sampled: 0,5,10,15, 20
- They mounted the SAME brakes (DA) on every frame to rule out the differences and only get the frame.
- The drag was measured to a precision of 1g in Dresden.
- They installed the same handle bar (custom) to also rule that variability out. They connected the handle bar with the dummy.

I took a few things also from the video: http://tv.tour-magazin.de/...bdf4b7a9ace27f4525f0

PS: I also updated my prev post with a high resolution scan.

Did they mount a bottle on the other frames and test? Wouldn't THAT be a more "real world", apples to apples comparison?

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http://bikeblather.blogspot.com/

If it's like their last TT bike test, they do indeed only test on the driveside. What I think is interesting is that Cervelo's DZ dummy has the right foot forward, whereas Tour's dummy has the left foot forward. So if Cervelo do all their development with that dummy, the resulting frame will be optimized for that leg being in that position, and having the leg in such a different position for the Tour test could easily give quite different results. Will we see bike companies requesting a copy of Tour's dummy so they can use it in their future development and make a bike that will test well in the Tour tests.......

I do recall that Velonews mentioned something about Felt possibly being slower, particularly at 0 yaw, because of something... I don't remember exactly.

Idk. But I think it's all not so important. Base line is that the aero bikes are pretty much all very close and a lot better than a std. road bike design. Which I'm glad about since I can now actually choose one that I also like to look at (sorry but the S5 is ugly IMO) and maybe base my decision on other things than just aero. To me, 4-5 Watts less or more is all within reason. 10-20W not anymore...

Of course it's important. If carrying a bottle on an S5 has NO effect, but it has a huge effect on the other frames then you may be back to the 10-20W differences again.

How often do you go ride/race a road bike with no bottle?

edit: Oh yeah...I found where the testing Cervelo did on hydration options showed that adding a round bottle to the downtube typically adds 40-50g of drag.

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http://bikeblather.blogspot.com/

If this proves anything, it is that my, "Eyeball Windtunnel" needs to be recalibrated. I thought for sure the S5 was better.

Tom isn't this data for the bike and rider? If so the difference in different rider dummy /position could account for the variation, no?