How much difference does an aero frame REALLY make?

neeb

OK, I know this is an oft-mentioned topic, but I never see any convincing evidence about it one way of the other.

Cannondale's claims for their new aero frame from the BR article:

"For example, it says that a 75kg rider riding at 300w saves 30w of effort on the SystemSix over the Evo".

"Barry says: 'If you're riding along at 30kph/18mph on a flat road the SystemSix saves 10 percent of your power,' "

These figures to me seem completely incredible and utterly at odds with oft-stated real world experience, where wheels count for more than the frame, the effect of those is pretty minimal, and of course tiny changes in position count for much more than both. 10% of my power represents the difference between being fit and unfit. Yet these figures claim to be based on exacting, quantified analyses of drag. Is it all just total bollox?

Hoping that someone with some genuine expertise and no marketing axe to grind will step in and offer reliably quantified advice.

cougie

That's absolute BS. Can you imagine a bike needing 10% less power ? Sky would be using them with pinarello liquid papered on the down tube.

joe_totale-2

I thought these claims are for the whole system including the wheels, frame, bars and stem and not just the frame?

But yeah, the numbers are probably too good to be true and we don't just ride in wind tunnels.

milemuncher1

With careful control of conditions and rider, the aero is a big advantage, in every day conditions, in the real world, not as much as some would have you believe. The aero advantage of a proper aero bike, can be made quite large ( you expend a goood 80 percent of your efforts riding a bike, moving air out of the way) but you do need to have other things in place to take full advantage of the savings on offer.

cougie

Of that 80% of your effort I'd imagine the lump of human must be something like 75% of the 80% ?

neeb

Ha ha, just googled and noticed/remembered that I asked a rather similar question just over a year ago.. getting senile.. ;-)
viewtopic.php?t=13078453

MiddleRinger

If the rider is set up in exactly the same position then an aero frame makes little difference. If you're talking a non-aero bike setup VS a full aero road setup then there's a noticeable difference when bombing along at speed for sure, otherwise we'd all be riding round tubed steel framed bikes with box section wheels.

But it's mostly just marketing BS, they gotta sell new bikes somehow!

cougie

Looking at the new bike - it looks pretty identical to most aero frames. I can't see anything earth shattering on it.

warrior4life

The Cannondale white paper is out there with all the test criteria and details.

haydenm

Same claims repeated in this as they are reading the same info, he does make an interesting point that for most people the weight sacrifice is worth it as you'll make up any time you lost on climbs on the flats

https://www.youtube.com/watch?v=y-GhJ3zIPCw

poweredbyidris

Makes no difference when Mr Sportive Rider buys one and immediately cable ties a very non-aero numberplate to the bars

haydenm

PoweredByIdris wrote:

Makes no difference when Mr Sportive Rider buys one and immediately cable ties a very non-aero numberplate to the bars

Or presumably puts 10cm of spacers under the stem?

joey54321

cougie wrote:

Looking at the new bike - it looks pretty identical to most aero frames. I can't see anything earth shattering on it.

Looks very different to me. Obviously, there is a limit to how different given it has to fit within UCI rules but it looks like there has been a lot of thought put in to that bike.

moonshine

FWIW, ia few years ag, in my first year of TTing and training with a proper coach (Xavier Disley @ RST/Aerocoach) I made a CdA drop equivalent to 30W of drag saving by optimising my full aero compliment of wheels, helmet, skinsuit, position and bike.

to put this in perspective - this was basef on a FTP of 300W, so an equivalent of 10% power improvement based on drag savings, plus i made 30W of FTP improvement by training.

I ride a Di2 P5-3 with HED Stingers, so pretty much one of the fasted UCI legal set-ups around

mamil314

neeb wrote:

completely incredible and utterly at odds with oft-stated real world experience

How often do you push 300W, or, for that matter, 200W o descents? Also, aren't you conveniently omitting the bit where they state these measurements are for full system with newly designed wheels.

neeb

moonshine wrote:

FWIW, ia few years ag, in my first year of TTing and training with a proper coach (Xavier Disley @ RST/Aerocoach) I made a CdA drop equivalent to 30W of drag saving by optimising my full aero compliment of wheels, helmet, skinsuit, position and bike.

to put this in perspective - this was basef on a FTP of 300W, so an equivalent of 10% power improvement based on drag savings, plus i made 30W of FTP improvement by training.

I ride a Di2 P5-3 with HED Stingers, so pretty much one of the fasted UCI legal set-ups around

Were those 30w of savings as compared to a non-aero setup, or to a previous aero (but non-optimised) setup?

neeb

mamil314 wrote:

neeb wrote:

completely incredible and utterly at odds with oft-stated real world experience

How often do you push 300W, or, for that matter, 200W o descents? Also, aren't you conveniently omitting the bit where they state these measurements are for full system with newly designed wheels.

Well, I think if anyone is “conveniently omitting” it’s Cannondale.. :-) :-) What are they comparing this full system against? (what wheels etc).

As far as watts on a descent goes it would depend on the gradient - I’m a relatively cautious descender but at 5% (as used in the comparison) I might put out between 200 and 300w for brief stretches on straight bits.

mamil314

They compare to top spec/lightest Supersix Evo

neeb

mamil314 wrote:

They compare to top spec/lightest Supersix Evo

With what wheels though? These will make more difference than the frame.

sloppyschleckonds

moonshine wrote:

so an equivalent of 10% power improvement based on drag savings,

WHS

Frame, wheels, aero socks, wheels, tires, helmets, skin suits

neeb

SloppySchleckonds wrote:

moonshine wrote:

so an equivalent of 10% power improvement based on drag savings,

WHS

Frame, wheels, aero socks, wheels, tires, helmets, skin suits

AAMOI though moonshine, was that 10% compared to a non-aero setup or to a non-optimised aero setup?

moonshine

neeb wrote:

moonshine wrote:

FWIW, ia few years ag, in my first year of TTing and training with a proper coach (Xavier Disley @ RST/Aerocoach) I made a CdA drop equivalent to 30W of drag saving by optimising my full aero compliment of wheels, helmet, skinsuit, position and bike.

to put this in perspective - this was basef on a FTP of 300W, so an equivalent of 10% power improvement based on drag savings, plus i made 30W of FTP improvement by training.

I ride a Di2 P5-3 with HED Stingers, so pretty much one of the fasted UCI legal set-ups around

Were those 30w of savings as compared to a non-aero setup, or to a previous aero (but non-optimised) setup?

from a pretty aero, but non-optimised setup ,I was previously riding a Ridley Dean with manual Dura ace, HED jet 6 wheels with custom Raltech disk cover, etc, so not a shabby starting place.

I ended up with a 19:46 '10 on the V718 off 316W AP and a CdA of 0.1904 iirc.. and plenty very short 20''s elsewhere, so reasonably handy.

stueys

Think it’s interesting to see where the manufacturers are going, it’s all totally integrated systems now. And I can see that a totally integrated wheel/tyre/fork/frame, all designed to work seemlessly together, could give a significant edge over seperate components which someone has put together. Be interesting to see how much of the aftermarket component world gets eaten by this trend, if I was an Enve or Zipp I’d be looking nervous at the moment.

Re a frame by itself, I don’t think it makes a huge difference. I’ve an r5, to that I’ve fitted an aero bar and deep section wheels. I figure that plus a good position are giving most of the goodness. But rationally I’d expect a complete system to be a step change.