tour mag aero tests a pinarello dogma and .....

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wingguy
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by wingguy

kgt wrote:Can anyone give a credible explanation on what is that - in terms of design - that provides F8's aero advantage Is it the fork? The rear end? A certain design concept that is not that clear?


I think you don't get that there will never be just one factor. If you read the white papers or marketing from any of the leading aero bike brands and they all make it clear that, as said above, the bike is a system and every element of it affects the elements behind it or next to it. There will never be just one clear, easily explainable thing that makes it better.

And again, the lack of a rear wheel cutaout is literally the only 'conventional' thing that the F8 has and the S5 doesn't, so I'm not sure where you're getting the whole conventional vs aero thing from.

2lo8
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by 2lo8

It's not just tube profiles either. There's also the consideration of interference drag wherever tubes meet, and on a diamond frame, there's quite a few of those, compared to something like a Lotus. There's also some debate on whether things like close stays and wheel cutouts are universally good. Tires have surface drag when they spin, easy enough to test with a lighter. The spinning changes the air flow and it can change between specific setups. It also tends to be where you have the cranks and legs moving and changing airflow depending on rotation. Wheel cutouts, definitely good in a static windtunnel test without a dummy. Most likely not nearly as significant when everything is moving with a rider on it. It looks aero though.
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2lo8
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by 2lo8

elzilcho wrote:Are there an open mold frames close to the F8? I've only seen the old 65.1 Dogma.


If by open mold, you mean counterfeits and rough copies, yes there are. Pinarello has been extremely good about pursuing legal action and keeping them hard to find and unbranded at the normal sources, Alibaba, DHGate and eBay, given how ubiquitous the old Dogmas were. You're not going to be able to find them by including either Pinarello or Dogma in your searches. That's no guarantee they're just as aero though, given that the old Dogma copies were not accurate reproductions. I suspect for many copied frames. they don't even buy an original sample, and certainly not one in every size, they just have someone mock up some CAD files based on detail pictures of the frames.
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fa63
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by fa63

kgt wrote:If you have not a clue or you are not interested you do not have to participate.

The irony...

I will stop posting now.

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kgt
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by kgt

I admitted from the start that I have not a clue on F8's aerodynamics while you think you have. It seems though that your contribution to the thread was just links to Pinarello's adverising. So clever, wow!

Anyway I do not care about general theories on airflows, the bike as a system etc. etc. but specific answers related to F8's design. I will not insist. End of thread.

ichobi
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by ichobi

Sometimes i dont know if you are trolling or what no offense. Whatever, tell us which part do you think the F8 is traditional? It looks awfully like an Aero bike to me. It doesnt look traditional like you claim it is at all.


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kgt
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by kgt

I might be sarcastic or provocative from time to time but no, I never troll.

By traditional I mean that it looks like many other contemporary frames. I don't find anything radical on a truncated airfoil section nowadays. Frames like S5 or Vias or FRD look much more 'sculpted' by the airflow. These are frames 100% designed in the wind tunnel with cfd analysis etc. F8 has some aero elements in its design but that's all. Pinarello does not claim it is a pure aero frame.

OTOH we have already seen full aero frames designed in the wind tunnel to have a mediocre aero performance in the lab. It's not that a frame that looks aero is actually aero.

So, my point is that if Pinarello can make a top aero frame that also looks so classy, 'calm' and balanced that is a huge success. In other words you don't need fancy shaped and extreme forms in order to make a top aero frame as some companies want to make us believe.

Of course Tour's test might be junk but that's another story. That is why I am asking from an expert to explain.

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BeeSeeBee
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by BeeSeeBee

It also scored worse than the Vias in aerodynamics, seatpost deflection, lateral fork stiffness, and bottom bracket stiffness, so there's certainly evidence that it's not some be all end all uberbike. There's a lot of subjectivity that goes into judging frames of course, and there are many ways to skin a cat, so to discount what other companies are doing as unnecessary is putting the F8 on a pedestal that there's no evidence it deserves. It's cool if your opinion is that it's an awesome frame, I think it's pretty cool too, but that's just like our opinion man :D

peted76
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by peted76

Regardless of this tour test, or the exact physics behind the aero'ness of the frame the F8 is firmly in superbike territory.

I'd love one.

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by User Name

******boogers*****
Last edited by User Name on Thu Jun 23, 2016 2:27 pm, edited 1 time in total.

2lo8
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by 2lo8

You can't even articulate how the F8 is not an aero bike compared to the S5, which is what it was being compared to.

Jaguar did lots of wind tunnel work and cfd. They basically designed the thing in the wind tunnel as you put it, short of the geometry and layup. You've already seen the marketing blurbs quoted (yet choose to ignore...). And you'll notice, they visually test the tube junctions to check interference drag to improve on it, where cfd tends to not do as well. They didn't simply mock up a few cfd iterations and test them to see which one was fastest in the tunnel. Truncated airfoil tubes not exotic enough for you? What makes the tube profiles of the S5 more exotic to you? Nothing. The F8 has an aero feature where the S5 doesn't. The hourglass shaped headtube and the beak over the brake. It's been known at least since the Lotus that having a funny looking head tube that isn't straight helps. Don't ask me why the S5 doesn't have it. The specific shape depends on how you want to direct airflow, but the only consideration the S5 gave was to narrow it from the front to decrease frontal area. The beak helps to smooth the airflow from over the brake to the headtube.

Doesn't sound like much? Maybe it isn't, but at least it's out front instead of in the back like the wheel cutout. Speaking of the rear end, the stays shield the rear brake, and that's in a less tubulent area than the wheel cutout. That you think the F8 isn't aero speaks more about your conception of the F8 as a non-aero bike, because despite the fact that F8 was heavily touted for it's aerodynamic improvements when it was introduced, to you the fact that it isn't sold along side a non-aero all-rounder means it can't be aero. Presumably because the aero Madone was only mediocre as an aero bike when Trek did not have the Emonda and the Madone was not pure aero. It's not like the F8 is an ultra-light 700g frame.

The Italian companies have always liked to hide information, and try to carve out a unique image, because they don't like being compared side-by-side with other brands. They know a lot of their marketing power comes from mystique and not being able to be compared to other brands. They're not selling you on the fact that it will save you X watts. They're selling based on the fact that it won the tour, it's even faster and better than before, it's unique, and it has that Italian brand name. If Pinarello told you it saves X watts, the next thing you do is compare it to the next brand that saves you Y watts, and then you try to make a rational technical evaluation. They don't want that, Italian brands have been the choice of certain consumers because there's an emotional attachment and something intangible about them.

That doesn't mean it's awful. It means Colnago could tell you head tube angles if they wanted, but all that would do is make you compare it to a cheaper non-Italian brand. They much prefer you thinking of Colnago handling with superlatives and the reputation for riding like it's on rails. Pinarello is likely doing the same thing. They did market all the aero work put into the bike, whether or not you deny it. But they would much rather you think about it as the best fastest tour winning bike in the world than looking to see if it's 0.2 watts slower than something else. They have never liked being compared to other bikes in their class from other brands. Of course they still like to say that it was a huge jump from the old Dogma. The Italian brands simply do not like to compete based on technical specs. They focus much more on branding power. And if you look at the reasons why people buy Italian frames, you can see why.

Maybe that explanation isn't good enough and you want to know why the technical information on the aerodynamics is lacking? Maybe it's because Pinarello didn't do the aerodynamics, they didn't do the cfd, they didn't do the windtunnel testing. That was Jaguar, and that's no secret. That doesn't mean it was Jaguar that wrote the marketing material. Obviously it was Pinarello. Or maybe they knew their relationship with Jaguar was going to be short lived. Maybe they didn't want to market their reliance on a sponsor that is no longer sponsoring their team.
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kgt
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by kgt

So according to your opinion truncated airfoil tubes, the hourglass shaped headtube and the beak over the brake are some important design elements to consider in the case of F8. That sounds fair, I appreciate your opinion. Thanks.

2lo8
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by 2lo8

I'm saying that you can't articulate why the S5 is aero but the F8 isn't.
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sawyer
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by sawyer

kgt wrote:
By traditional I mean that it looks like many other contemporary frames. .


I love this sentence

Anyway, I think you have an entirely legitimate question as to how Pinarello have got there through a slightly different route to Spesh, Scott etc, but you're hugely overstating the difference in the essential design elements, and inadvertently focussing - somewhat ironically - on different marketing strategies ...
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jekyll man
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by jekyll man

2lo8 wrote:You can't even articulate how the F8 is not an aero bike compared to the S5, which is what it was being compared to.

Jaguar did lots of wind tunnel work and cfd. They basically designed the thing in the wind tunnel as you put it, short of the geometry and layup. You've already seen the marketing blurbs quoted (yet choose to ignore...). And you'll notice, they visually test the tube junctions to check interference drag to improve on it, where cfd tends to not do as well. They didn't simply mock up a few cfd iterations and test them to see which one was fastest in the tunnel. Truncated airfoil tubes not exotic enough for you? What makes the tube profiles of the S5 more exotic to you? Nothing. The F8 has an aero feature where the S5 doesn't. The hourglass shaped headtube and the beak over the brake. It's been known at least since the Lotus that having a funny looking head tube that isn't straight helps. Don't ask me why the S5 doesn't have it. The specific shape depends on how you want to direct airflow, but the only consideration the S5 gave was to narrow it from the front to decrease frontal area. The beak helps to smooth the airflow from over the brake to the headtube.

Doesn't sound like much? Maybe it isn't, but at least it's out front instead of in the back like the wheel cutout. Speaking of the rear end, the stays shield the rear brake, and that's in a less tubulent area than the wheel cutout. That you think the F8 isn't aero speaks more about your conception of the F8 as a non-aero bike, because despite the fact that F8 was heavily touted for it's aerodynamic improvements when it was introduced, to you the fact that it isn't sold along side a non-aero all-rounder means it can't be aero. Presumably because the aero Madone was only mediocre as an aero bike when Trek did not have the Emonda and the Madone was not pure aero. It's not like the F8 is an ultra-light 700g frame.

The Italian companies have always liked to hide information, and try to carve out a unique image, because they don't like being compared side-by-side with other brands. They know a lot of their marketing power comes from mystique and not being able to be compared to other brands. They're not selling you on the fact that it will save you X watts. They're selling based on the fact that it won the tour, it's even faster and better than before, it's unique, and it has that Italian brand name. If Pinarello told you it saves X watts, the next thing you do is compare it to the next brand that saves you Y watts, and then you try to make a rational technical evaluation. They don't want that, Italian brands have been the choice of certain consumers because there's an emotional attachment and something intangible about them.

That doesn't mean it's awful. It means Colnago could tell you head tube angles if they wanted, but all that would do is make you compare it to a cheaper non-Italian brand. They much prefer you thinking of Colnago handling with superlatives and the reputation for riding like it's on rails. Pinarello is likely doing the same thing. They did market all the aero work put into the bike, whether or not you deny it. But they would much rather you think about it as the best fastest tour winning bike in the world than looking to see if it's 0.2 watts slower than something else. They have never liked being compared to other bikes in their class from other brands. Of course they still like to say that it was a huge jump from the old Dogma. The Italian brands simply do not like to compete based on technical specs. They focus much more on branding power. And if you look at the reasons why people buy Italian frames, you can see why.

Maybe that explanation isn't good enough and you want to know why the technical information on the aerodynamics is lacking? Maybe it's because Pinarello didn't do the aerodynamics, they didn't do the cfd, they didn't do the windtunnel testing. That was Jaguar, and that's no secret. That doesn't mean it was Jaguar that wrote the marketing material. Obviously it was Pinarello. Or maybe they knew their relationship with Jaguar was going to be short lived. Maybe they didn't want to market their reliance on a sponsor that is no longer sponsoring their team.


post of the day :thumbup:

if anyone's interested on understanding the basics of aerodynamics in sport (esp cycling) , Coursera do a 6 week course alongside the TuE thats definitely worth doing 8)
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