[quote=maxim809 post_id=1773283 time=1665939606 user_id=69654]
[quote=C36 post_id=1773259 time=1665929817 user_id=69709]
His tcr / ultimate video as little value, on the canyon, hands are less stretched, he sits further in front and in consequence, head is way higher and back angle is different… and he refuses to recognise it.
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Agreed, the fit matters a ton.
What Arthur has done isn't actually a "bike isolation test", but a full rider + bike system test.
[img src=" https://i.imgur.com/qUpTW53.gif "]
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The fit DOES matter a ton, yet, if going from that baseline position to a perfect aero hoods (ie sphinx, breakaway position) saves 25-35w depending on speed, we can't pretend that those relatively tiny differences in position can amount to anything more than a handful of watts. And I'd have expected the Madone to still be faster than the TCR even with these minuscule differences in position.
*Tour Aero Bike Tests*
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TobinHatesYou
- Posts: 12544
- Joined: Mon Jul 24, 2017 12:02 pm
Ultimately it does support the argument that the frame itself should be one of the last marginal aero gains. Get a bike fit, buy tight roadsuits/speedsuits, aero helmets, aero socks and shoes. Buy narrower bars as long as they don’t cause your elbows to poke out. Shorter cranks so you can raise your saddle and sit farther forward in a more TT-like position. Stop taping your bars at the tops and buy some 50mm deep wheels.
Then buy the aero frame. Or buy it because it looks like a spaceship and the placebo will make you ride more, ride harder.
I don't think the video was shot during the actual tests. In the Madone video there was no wind blowing!
You guys are really hard on David Arthur! You guys act like this is some double blind scientific test and not just some youtube entertainment.
As Tobin says, don't sweat the super bike frame. Get good wheels, kit, helmet, etc.
My problem is that I tried to tell him asside, first he told me I am wrong, then I took the time to send him a photoshop putting the 2 images on top of each other... and ignore.AJS914 wrote: ↑Mon Oct 17, 2022 12:36 amI don't think the video was shot during the actual tests. In the Madone video there was no wind blowing!
You guys are really hard on David Arthur! You guys act like this is some double blind scientific test and not just some youtube entertainment.
As Tobin says, don't sweat the super bike frame. Get good wheels, kit, helmet, etc.
What he tries to do is VERY difficult and I would have appreciate a "shit, ok, lets improve" rather than a "lets continue making views".
The goal to go on a wind-tunel is to measure, so to do things right if not that's missinformation... or to say "what we are measuring is smaller than what few cm of fitting can generate", not very sexy... but that's the reality.
Last edited by C36 on Mon Oct 17, 2022 10:34 am, edited 1 time in total.
I have
. 2-3 years ago I had this discussion with one of their journalist and they have now clarified under this article. They talk about ACCURACY and REPEATABILITY which is rare enough to be highlighted. practically, you are around +/- 1W between 2 numbers published. That seems small but with the mannequin they removed all variables.
https://www.tour-magazin.de/kaufberatun ... windkanal/
"The measurement accuracy within a measurement campaign – which is usually the data that is published within a story – is +/- 0.25 W. The repeatability between different campaigns is +/- 1 W."
for those who want to understand better the difference
- Accuracy: how far is your average compared to the "absolute, real value" --> in absolute we care quite little we are interested in relative differences.
- Repeatability: how different will 2 subsequent measurement be --> what we want, I want to compare a bike tested in march with one tested in October and compare the results.
This drawing illustrate this
Last edited by C36 on Mon Oct 17, 2022 10:32 am, edited 1 time in total.
Long shot here... I am looking for 1995 Tour-magazin where they tested 49 frames. Interested to see the evolution of frame stiffness... Original title was ""Velowerkstatt 4 – Rahmen". Klein finished on top and it highlighted how flexible were many frames, specially in the front.
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wheelsONfire
- Posts: 6292
- Joined: Mon Jul 07, 2014 8:15 am
- Location: NorthEU
How much difference does aero bike frame make?
The advantage of an aero frameset is typically cited as anything between 10 and 30w at 40kph. So again, making very ballpark calculations, at the same power you'd (very roughly) travel 0.5kph faster. Assuming you're not travelling at 40kph for the whole ride, 0.3kph on average sounds perfectly reasonable.
The advantage of an aero frameset is typically cited as anything between 10 and 30w at 40kph. So again, making very ballpark calculations, at the same power you'd (very roughly) travel 0.5kph faster. Assuming you're not travelling at 40kph for the whole ride, 0.3kph on average sounds perfectly reasonable.
Bikes:
Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)
Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.
Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)
Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.
It's a recurring question. The answer widely depends on what do you mean by "classic", what do you mean by "aero", and what do you mean by "bike". A few examples with ballpark figures:
- Going from a completely unoptimised bike (think TI bike with round tubes, several exposed cables, wide round bars fully wrapped in double tape, round seatpost, shallow and narrow wheels with too wide tyres etc) to a 100% aero optimised setup could save ~ 35-40w @ 45km/h, or even more - though I don't have Tour test results at hand right now, I'm going from memory.
- Going from a relatively half-baked aero bike (think something along the lines of an imaginary Aethos/TCR with a semi-aero cockpit and mid depth carbon wheels, fewer and somewhat hidden cables) to a 100% optimised setup would probably be 15-20w @ 45km/h.
- Going from a fully-aero-optimised roundish tube frame (as above, something shaped like the Aethos/TCR but with fully hidden cables, uncompromisingly aero cockpit, deep carbon wheels, etc) to a 100% optimised setup is probably going to be 7-15w @ 45km/h.
A few usual caveats / notes are that:
- those figures are likely to shrink somewhat once a rider is put on a bike
- those figures would not be nearly as impressive at regular speeds, e.g. they'd roughly halve at 30km/h.
- the frame represents a relatively small portion of the saving compared to what you'd think.
- most of the figures quoted are for bikes fully 'as stock' and most modern aero bikes are developed as "systems", which means messing with the components may affect aero performance negatively, e.g. Most often people buy bikes like the SystemSix, whine about the proprietary cockpit being an anchor and put a less aero option on - things like these..
You're smoking crack.
1) an Aethos and a Classic round tube bike measure differently. A good classic bike will perform better than a modern AL or CF round tube bike because the tubes are half the size. Specialized has a YouTube vid of this.
2) worst case round tube bike with all the wrong parts on a modern bike was about 239w on their test. All the right parts on the wrong frame put those bikes around 224w in Tours test. All the best parts was about 202w. Aero handle bars are about 5-8w and the wheels are around 10w. Clean cable routing (vs OEM excessive lengths) is probably 2-3w. At best you're looking at 20w, but most aero road bikes are around 210w. 10w is more realistic.
3) None of those bikes ever has a water bottle on them. Aside from the bike-specific aero bottles, which are kind of useless realistically, the water bottle will affect the aero bike a lot more than the round tube bike.
4) it depends on the frame size. Aero frames dont matter as much for smaller people.
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