"Lightness" vs "Aeroness" UPDATED 10/2023

[Nickldn]

Not wasting your time at all. By all accounts the SL8 rides really well, and another bike is always good. Mine is a pretty subjective choice, and personal. I prefer the behavior of rim and am lucky there are a couple of brands still making them.

I guess the question is will I feel a difference in the ride responsiveness, aero and weight between the ZX1 and SL8.

This really goes to the heart and beyond the "Lightness vs. Aeroness" topic as it pits a 2018 frame against a 2023 frame. And lightness no longer comes at the expense of "aeroness" in 2024.

I can measure frame weight and yes the SL8 is the winner, but the other aspects of the topic such as "aeroness", stiffness and responsiveness are much more difficult to pin down, or actually totally subjective.

What I do know is with the SL8 I'll end up with a lighter bike. But really that's all I know. The SL8 may be more aero, or not so much and it may be stiffer, or not. Quite how that will translate into ride feel is at best conjecture.

I'm still committed to spending a load of money on the SL8 so will report back.

[sigma]

Good to see that very little has changed when it comes to people evaluating marginal gains. still have the "just wear shoe covers instead" crowd who misses the point. Still have people who dont consider the entire picture.

The super six looks good. any "cooking" of the specs when cannondale sent that in?

I believe the SS evo 4 was tested with a 2 piece bar / stem and the vision 50L wheels. So, it should pick up a couple to 3 watts additionally to get it quite close to pure aero territory.

[Hexsense]

^ and tested using round water bottle as well.
The bike has their specific aero bottle and cage.

[cajer]

Do we know what yaw weighting tour magazine uses?

[TobinHatesYou]

^ and tested using round water bottle as well.
The bike has their specific aero bottle and cage.

I'm trying these out on my Domane RSL and so far a big thumbs down from me. The plastic cages are flimsy, the aero bottles are hard to insert and normal bottles are even harder to insert.

[tyoac]

Good to see that very little has changed when it comes to people evaluating marginal gains. still have the "just wear shoe covers instead" crowd who misses the point. Still have people who dont consider the entire picture.

The super six looks good. any "cooking" of the specs when cannondale sent that in?

I believe the SS evo 4 was tested with a 2 piece bar / stem and the vision 50L wheels. So, it should pick up a couple to 3 watts additionally to get it quite close to pure aero territory.

It was a stock SSE4 Hi-Mod2 with the 2 piece bar and their own inhouse HollowGram wheels. Tour mentioned in another articel on their website that it dropped to 203 or 204 watts (would need to look it up again) with some deeper, more aero wheels. Combine that with a 1 piece cockpit and you should be bang on with the best of the best I would guess.

[GrassQ]

They use "sweep" from 20 degree to -20 degree and 41 datapoints (probably 0 degree and 20 /per degree both sides ) .
Chosen surrounding average wind is 10 km/h (2,8 m/s) and they use Weibull distribution.
Above is what Tour has informed.

That wind distribution is maybe in low side if you are living for example in coast or "open field" area. If I remember right in Finland and in those areas average wind is about 3,5-5 m/s. And of course conditions varies in every ride.

In the picture in one example what surrounding winds could be in 3/ms average (and k=2) in Weibull distribution,blue curve

[solarider]

The level of geekery here is off the scale.

Unless any of the user names is masking a grand tour winner's identity who's income and palmares is governed by watts and split seconds this really is splitting hairs.

The best bike is one that fits and you enjoy riding. Technology has progressed to such an extent that one bike is very much like another. The yaw angle, the air temperature, the size, etc. really?!

The biggest drag is still the lump riding it.

[cajer]

They use "sweep" from 20 degree to -20 degree and 41 datapoints (probably 0 degree and 20 /per degree both sides ) .
Chosen surrounding average wind is 10 km/h (2,8 m/s) and they use Weibull distribution.
Above is what Tour has informed.

That wind distribution is maybe in low side if you are living for example in coast or "open field" area. If I remember right in Finland and in those areas average wind is about 3,5-5 m/s. And of course conditions varies in every ride.

In the picture in one example what surrounding winds could be in 3/ms average (and k=2) in Weibull distribution,blue curve

That's really unfortunate that they are weighting towards high yaw. Espically as most of the data shows that low yaw dominates. I really wish they would show yaw sweeps now.

[GrassQ]

I dont know the yaw angles, but for me it seems that they weigted low yaw angles
This is based that blue curve/wind distribution which is conservative (and average wind is quite low) and how that effects to yaw angles.
Chosen average wing could also be little bit lower or higher, but here are not right or wrong decisions in these limits +-1 m/s (this is only quessing).
If you take for example some Kona Ironman TT wind conditions to calculation base, then calculations doesnt represent normal conditions in any meaning

[tymon_tm]

what i'm wondering re: aero in real life is that some reviews claim bikes like Cannondale Evo "don't give as much kick as aero bikes" despite it had tested better than many of them.

having some minor experience i can relate to that - old Aeroad from 5-7 years ago (with rim brakes, cables and old fashioned cosmics) felt very, very quick. so did Madone SLR with 'old' XXX wheels. now I've got a borrowed SL8 (yuck) on relatively fast Metron 50-whatever wheels and can't feel a thing when getting above - say - 35 kmh. it's not slow by any means but just hasn't got any reward candy for me going fast-ish. maybe it's winter clothes or my negative attitude towards Spec (really dislike that brand) but i can't help thinking there's some hidden x-factor behind all these aero rigs that's not really measurable

Sounds like you're describing the difference between older rim brake frames and disk frames in general. Rim brake frames are known for feeling more snappy and responsive than disk. The (marketing) story goes that disk frames are no slower, even with (or because of) wider tyres.

I have a 2017 Propel rim aero bike with deep tubular wheels. Nothing feels more responsive to ride and guess what, the strava segment times are pretty good too.

I'm not a fan of discs, but no, I don't think brakes have anything to do with that 'feel'. and I wouldn't call it 'responsiveness'; it's how these bikes appear to become alive at higher speeds.

I'm sure many of you here have experienced that effect first hand. obviosuly there are also those who have aero bikes but don't have a clue what I'm talking about. I'd say the key is, doh, speed. I nearly bought a Madone off a guy who claimed it was 'clumsy'. he rides in group rides only, afaik they average around 25-28 kph...

[Nickldn]

what i'm wondering re: aero in real life is that some reviews claim bikes like Cannondale Evo "don't give as much kick as aero bikes" despite it had tested better than many of them.

having some minor experience i can relate to that - old Aeroad from 5-7 years ago (with rim brakes, cables and old fashioned cosmics) felt very, very quick. so did Madone SLR with 'old' XXX wheels. now I've got a borrowed SL8 (yuck) on relatively fast Metron 50-whatever wheels and can't feel a thing when getting above - say - 35 kmh. it's not slow by any means but just hasn't got any reward candy for me going fast-ish. maybe it's winter clothes or my negative attitude towards Spec (really dislike that brand) but i can't help thinking there's some hidden x-factor behind all these aero rigs that's not really measurable

Sounds like you're describing the difference between older rim brake frames and disk frames in general. Rim brake frames are known for feeling more snappy and responsive than disk. The (marketing) story goes that disk frames are no slower, even with (or because of) wider tyres.

I have a 2017 Propel rim aero bike with deep tubular wheels. Nothing feels more responsive to ride and guess what, the strava segment times are pretty good too.

I'm not a fan of discs, but no, I don't think brakes have anything to do with that 'feel'. and I wouldn't call it 'responsiveness'; it's how these bikes appear to become alive at higher speeds.

I'm sure many of you here have experienced that effect first hand. obviosuly there are also those who have aero bikes but don't have a clue what I'm talking about. I'd say the key is, doh, speed. I nearly bought a Madone off a guy who claimed it was 'clumsy'. he rides in group rides only, afaik they average around 25-28 kph...

As we know the layup for disk brake forks and also many other parts of the disk frame needs to be different to rim frames in order to withstand disk braking forces (but other design choices may also apply).

It is the disk frame/fork design and not the actual disk brake itself which is said to affect the ride feel and cause the less responsive sensations you experience. If you were to somehow adhere disk brakes to a rim frame it would likely retain its springy and fabulous feel (all else being equal, which it won't be).

In order words there is more to a rim brake frame than just rim brakes.

[cajer]

I dont know the yaw angles, but for me it seems that they weigted low yaw angles
This is based that blue curve/wind distribution which is conservative (and average wind is quite low) and how that effects to yaw angles.
Chosen average wing could also be little bit lower or higher, but here are not right or wrong decisions in these limits +-1 m/s (this is only quessing).
If you take for example some Kona Ironman TT wind conditions to calculation base, then calculations doesnt represent normal conditions in any meaning

If you look at actual measured distributions here:

https://www.slowtwitch.com/Tech/Real_Wo ... %20degrees.

You'll see that the vast majority of time is spent under 7 degrees which is very much not the case in the tour weightings.

So yea I don't really trust the tour data very much anymore

[GrassQ]

Tour sweep and surrounding wind conditions are not the same as yaw angles, but those are a base to calculation yaw angles.
Tour yaw angles are are also very much in low side.
Tour use in their calculations low/normal wind distribution, and spending time there so their results implicate quite well normal riding conditions.
Althoug tour hasnt tell exact distribution.

[BalticSea]

what i'm wondering re: aero in real life is that some reviews claim bikes like Cannondale Evo "don't give as much kick as aero bikes" despite it had tested better than many of them.

having some minor experience i can relate to that - old Aeroad from 5-7 years ago (with rim brakes, cables and old fashioned cosmics) felt very, very quick. so did Madone SLR with 'old' XXX wheels. now I've got a borrowed SL8 (yuck) on relatively fast Metron 50-whatever wheels and can't feel a thing when getting above - say - 35 kmh. it's not slow by any means but just hasn't got any reward candy for me going fast-ish. maybe it's winter clothes or my negative attitude towards Spec (really dislike that brand) but i can't help thinking there's some hidden x-factor behind all these aero rigs that's not really measurable

That's because you're using feelings (subjective) to compare bikes rather than physics/data (objective). Quite often people hear, see and feel what they want to. It's entirely possible that your personal bias against Spesh makes you feel negatively about it.