"Lightness" vs "Aeroness" UPDATED 10/2023

[Robius]

interesting white paper by Quintana Roo.

the price for a frameset is quite shocking. 3K for a custom painted aero road bike. unlike Factor they tested in the most accurate A2 Low Speed Wind Tunnel in North Carolina. In the real world testing with 2 water bottles i see the specialized tarmac 7 beats the new cervelo s5. only issue we need more details on what wheelsets were tested.

tarmac is impressive and the SRsix is shocking $/aero.

https://www.slowtwitch.com/Products/Roa ... _7884.html

Direct link to the whitepaper: https://cdn.shopify.com/s/files/1/0006/ ... 1614203184

Long story short, buy aero water bottles for your Canyon Aeroad.

[Lina]

This has always bothered me on aero bikes that have narrow downtubes. They may be great in a wind tunnel without any bottles but what happens when you slap two bottles in there.

[FlatlandClimber]

I made it sound like all pros have zero clue, which of course is bs. But many of the decisions are not based on efficiency, but on feel.
WVA and MvdP raced the final 45 minutes or so of Ronde van Vlaandere 2020 solo, and VdP had 40mm wheels and VA even shallower wheels.
I looked up the weather, wind wasn't a big deal that day.
What ever made them choose these wheels wasn't efficiency.
This is one of hundreds of examples.

Well, De Ronde is a race that is not won or lost on efficiency or calculations but on nasty *f##k* of really stinking steep climbs. I think most contenders, being able to hide inside the pack or team until it's their time to shine, would put their bets on a shallower and lighter wheelset for all-out balls-to-the-mfin-Muurs attempts at creating or closing gaps in a few key places.

...and when they're off the front, they're surely not stopping for a bike/wheel change.

When the world's (arguably) two best riders do educated choices that we do not understand or agree with, I think one has to resort to a becoming humility for what we do not realise.

We have discussed this more than enough. 2020s Ronda was NOT WON ON A CLIMB but on a long flat breakaway. I don't want to this discus this for the 700th time, but their choice wasn't the fastest. Although the climbs are steep, most of them are still fast, because they are very short and ridden all out.
Ronde isn't the only example of this.

[spartacus]

Pros gonna pro. My guess is they're wary of deep wheels because they're riding in huge packs. They probably like non-aero bars for comfort reasons as well.

[jmechy]

interesting white paper by Quintana Roo.

the price for a frameset is quite shocking. 3K for a custom painted aero road bike. unlike Factor they tested in the most accurate A2 Low Speed Wind Tunnel in North Carolina. In the real world testing with 2 water bottles i see the specialized tarmac 7 beats the new cervelo s5. only issue we need more details on what wheelsets were tested.

tarmac is impressive and the SRsix is shocking $/aero.

https://www.slowtwitch.com/Products/Roa ... _7884.html

Direct link to the whitepaper: https://cdn.shopify.com/s/files/1/0006/ ... 1614203184

Long story short, buy aero water bottles for your Canyon Aeroad.

Interesting that they don't say which generation of aeroad, and don't have a picture of it.

[Singular]

I made it sound like all pros have zero clue, which of course is bs. But many of the decisions are not based on efficiency, but on feel.
WVA and MvdP raced the final 45 minutes or so of Ronde van Vlaandere 2020 solo, and VdP had 40mm wheels and VA even shallower wheels.
I looked up the weather, wind wasn't a big deal that day.
What ever made them choose these wheels wasn't efficiency.
This is one of hundreds of examples.

Well, De Ronde is a race that is not won or lost on efficiency or calculations but on nasty *f##k* of really stinking steep climbs. I think most contenders, being able to hide inside the pack or team until it's their time to shine, would put their bets on a shallower and lighter wheelset for all-out balls-to-the-mfin-Muurs attempts at creating or closing gaps in a few key places.

...and when they're off the front, they're surely not stopping for a bike/wheel change.

When the world's (arguably) two best riders do educated choices that we do not understand or agree with, I think one has to resort to a becoming humility for what we do not realise.

We have discussed this more than enough. 2020s Ronda was NOT WON ON A CLIMB but on a long flat breakaway. I don't want to this discus this for the 700th time, but their choice wasn't the fastest. Although the climbs are steep, most of them are still fast, because they are very short and ridden all out.
Ronde isn't the only example of this.

Here's the deal; no, it was not won between the two/three main contenders on the climbs - and it might very well have been because they effectively managed to keep it together and marking eachother out. One of them opting for a "faster" wheel would have maybe given him an advantage in spreadsheets and modelling, but that's not where it goes down - it's on a steep, cobbled old hill where opening or not closing a gap can make or break a day.

Everyone has the right to their opinion and belief, but at one thing you are wrong; obviously, their choice was the fastest. By a small margin, but still. Once again, humility for the limits of our understanding is becoming.

[FlatlandClimber]

No! Their choice wasn't the fastest for the course. WTH.
Just because they won doesn't mean they made the perfect choice.
Firstly, WVA, MVDP and Ala were just the best riders in the race. The physiological advantage of them over another rider can easily be higher than the advantage between shallower and deeper rims.
Secondly, most of the other riders were on shallow wheels, too. So that theoretical advantage evaporates right there.
Thirdly, creating a gap early on is actually not that difficult, when you have their power numbers. It's more of a tactical question of "when". Just watch the UAE Tour, where most of the breakaways are started on the flat, and most of them are reeled in again. Not because of wheel choice, but because maintaining a gap is much more difficult than creating a gap.
Lastly, while humility is always a good thing, I feel like you are suggesting that they know something that my limited mind just can't comprehend. Since I am not the inventor of aerodynamics, but just someone who believes in science over feels. There is no scientific explanation of the "lighter" (since riders are sponsor limited, they couldn't even choose actually light wheels), being faster on the course.
I am not claiming I know it all and every other idea is wrong. But I have yet to see a convincing argument on how a 200g saving would be a greater advantage over this course, than a 60mm wheel is over a 30 or 40mm wheel.
To underpin my point, the Teams know that Aero matters a lot on that course. Both WVA and MVDP were on their team's respective aero frame, not the lighter climbing frame.
Wheel choice is usually up to the rider and most of them opt for shallow... many of the Jumbo guys even ride the flat stages of tour of UAE on shallow wheels also, probably they know something all the other teams do wrong...

[gzon]

This has always bothered me on aero bikes that have narrow downtubes. They may be great in a wind tunnel without any bottles but what happens when you slap two bottles in there.

BMC and Pinarello have recognized this fact and also have frames that shield the bottles for a "real world" aero benefit. There are probably more manufacturers that have done this as well.

[FlatlandClimber]

This has always bothered me on aero bikes that have narrow downtubes. They may be great in a wind tunnel without any bottles but what happens when you slap two bottles in there.

BMC and Pinarello have recognized this fact and also have frames that shield the bottles for a "real world" aero benefit. There are probably more manufacturers that have done this as well.

3T even did this for their Exploro.
That even works well in the wind tunnel. A water bottle (550ml) is something like 50% less penalty on an F10 than it is on a Cervelo S5.

[mrlobber]

Direct link to the whitepaper: https://cdn.shopify.com/s/files/1/0006/ ... 1614203184

Long story short, buy aero water bottles for your Canyon Aeroad.

My 2 problems with this QR testing are the following:

1) it has been done at 30mph, thus 46kmh. Who (except pros in races) rides his/her bike solo at those speeds?? Even TT bikes usually are tested at 45 kmh. This means that the wattage differences at "more realistic" speeds are quite a bit lower.
2) take note at yaw angles. If you're doing 45+ kmh, don't tell me you're really facing anything outside of -5...+5 range except extreme crosswind circumstances.

Third, more of a "traditional" (whenever aero testing is involved) note: that QR bike looks totally similar to all recent disc semi-aero bikes. What's the "secret sauce" which suddenly allows them outperforming all others? If the answer is "fatter downtube", please keep me from LOLing.

P.S. I agree on the negative bottle effect on narrow-sized downtube bikes - this has already been exposed since 2016, and I've told it here as well, that, for instance, Felt always avoided the question how their otherwise-magnificently-aero 2nd gen AR rim brake bike performed with bottles. Guess why

[Singular]

I love arguing about things like these where science, beliefs, traditions and vanity collide!

Just because they won doesn't mean they made the perfect choice.

There is no perfect choice. But they arguably made the best choice. Everything equipment related is a compromise (for me, the greatest compromise is cost...) and they obviously opt for something that is optimised for other things than you and I seem to choose. I've heard it a lot from the guys and gals responsible for tech and equipment in the pro ranks; for contenders, one could easily justify in the large perspective severely suboptimal choices in order to gain even small advantages in the situations where te race is decided. Sometimes, it is a measurable advantage. Sometimes it is only sensation. If it makes the spaceship go faster, that is what it will be.

Secondly, most of the other riders were on shallow wheels, too. So that theoretical advantage evaporates right there.

No, it just indicates a level playing field. In this case, another choice would potentially propose a (theoretical or practical) disadvantage instead. It's in the "If everyone's on X, no one is on X" theme (now it's aero bikes, twentyfive years ago it was...something else).

Thirdly, creating a gap early on is actually not that difficult, when you have their power numbers. It's more of a tactical question of "when". Just watch the UAE Tour, where most of the breakaways are started on the flat, and most of them are reeled in again. Not because of wheel choice, but because maintaining a gap is much more difficult than creating a gap.

Stage racing and broadcasted breakaways is a different animal, not always relevant from a sporting perspective. In general, the break happens because it is allowed to and caught because it is decided.

No! Their choice wasn't the fastest for the course. WTH.

But I have yet to see a convincing argument on how a 200g saving would be a greater advantage over this course, than a 60mm wheel is over a 30 or 40mm wheel.

Oh, it's right there for you - at the top of the podium! I'm teasing a bit, but the shallow wheels spent the least time on the course, had the highest average speed and finished first. What can be faster than that?

To underpin my point, the Teams know that Aero matters a lot on that course. Both WVA and MVDP were on their team's respective aero frame, not the lighter climbing frame.
Wheel choice is usually up to the rider and most of them opt for shallow... many of the Jumbo guys even ride the flat stages of tour of UAE on shallow wheels also, probably they know something all the other teams do wrong...

Perhaps the bumblebees haven't heard that rotational weight does not fly anymore?

Lastly, while humility is always a good thing, I feel like you are suggesting that they know something that my limited mind just can't comprehend.

Nopes, I'm just saying that when someone who brings even more skill, experience and knowledge than ourselves (and I guess you are just as involved, interested, educated and enthusiastic as I am) proposes a view or practice that contadicts your beliefs, one should not opt for a "why-not-like-me" but a "why-do-like-they" approach. I do, just as you, follow the findings of testing and science and for the type of riding that you and I do a "fast" setup is, well, faster (and looks better). But I'm not racing with a hundred others in a situation where my cycling performance is influencing my livelihood (then I'd be even poorer than today...) and I'm often more concerned with appearance than performance (Campag! Painted bikes! Shiny stuff!) and would therefore be caught with an aero bike and shallow wheels.

[FlatlandClimber]

I agree that 45kph is not a speed most people can ride at for very long. As a general rule of thumb, power at 30kph (18.6mph) is around half that of what you require at 45mph (28mph). Many of the advantages can therefore be "cut" in half when extrapolating the aero advantage at 30kph, but not all! Some aero features work better at lower speeds while others work better at higher speeds. The infamous aero-foil just doesn't work so well at bike speeds.
A yaw angle of more than 5 can definitely be seen at 45kph and more unless you never have crosswinds. A set up that works well at a wide range of yaw angles is likely to work better in real life, where air flow isn't as "straight" as it is in a wind tunnel.

However, 45kph is not completely irrelavant to people who aero Van Aert or Ganna. In breakaways, lead outs, sprints, and head wind sections, a relative air speed of 45kph can be achieved by most of us. That's probably where the aero bike comes in best, to save you a few watts following a break, or make riding in harsh headwinds a little quicker...

[FlatlandClimber]

I will not discus all of this again.
Just two points:
- the "fastest" set up is not the one that crosses the line first, but the one that is the most efficient for a given course. Efficiency is fast. Van Aert and VDP beat most pros on a course like that even on a early 2000s round tube bike, with box section wheels. But the margin they win by is smaller than with a faster set up. The win was by margins of a second, so Van Aert could have done better with slightly faster set up (at least that's what the science says)-
- rotational weight is probably the most overvalued thing in cycling ever! Rather look into aerodynamics of a rotating object, that is A LOT MORE important than its weight. Aero savings on your wheels actually do "more" than on your frame, while the same cannot be said for weight savings (downhill force just doesn't care ...)

[Singular]

I will not discus all of this again.
Just two points:
- the "fastest" set up is not the one that crosses the line first, but the one that is the most efficient for a given course. Efficiency is fast. Van Aert and VDP beat most pros on a course like that even on a early 2000s round tube bike, with box section wheels. But the margin they win by is smaller than with a faster set up. The win was by margins of a second, so Van Aert could have done better with slightly faster set up (at least that's what the science says)-
- rotational weight is probably the most overvalued thing in cycling ever! Rather look into aerodynamics of a rotating object, that is A LOT MORE important than its weight. Aero savings on your wheels actually do "more" than on your frame, while the same cannot be said for weight savings (downhill force just doesn't care ...)

Here's the really interesting question you need to ask; So, why do they make these choices?

[Lina]

Direct link to the whitepaper: https://cdn.shopify.com/s/files/1/0006/ ... 1614203184

Long story short, buy aero water bottles for your Canyon Aeroad.

My 2 problems with this QR testing are the following:

1) it has been done at 30mph, thus 46kmh. Who (except pros in races) rides his/her bike solo at those speeds?? Even TT bikes usually are tested at 45 kmh. This means that the wattage differences at "more realistic" speeds are quite a bit lower.
2) take note at yaw angles. If you're doing 45+ kmh, don't tell me you're really facing anything outside of -5...+5 range except extreme crosswind circumstances.

1) The speed doesn't matter as long as it's something that can be achieved with a bike unless you're trying to do something like optimizing gear for a record attempts. The aerodynamics don't dramatically change between 30 and 50 km/h. Obviously the differences are smaller in lower speeds but does that really matter, the order of the bikes won't change.

2) Where I live having 5 - 10 m/s winds is the expected state of things. Obviously it won't be straight side winds all the time but there are plenty of times when your yaw is much greater than -5...+5. Even at high speeds.