Are Aero Bike Really Worth it? An Aerodynamics Expert Reveals the Truth... 

Aero bikes can be very enticing but I can't help but notice that the hitters at my group ride are fast on everything they ride.

Nathan is great, while he is representing Cannondale he kept the conversation interesting and valuable without making it a pure marketing excercise. Great interview.

To sum it up. Its YOU that matters the most not necessarily just the bike

I love the design of an arrow bike. It looks fast just sitting there. If you are lucky enough to be able to afford a high end bike I think it makes you want to ride harder longer and faster. Bicycling changed my life!!!!!!!!

Fascinating. What’s interesting is, if you look at the main brands’ bikes today, how little they differ really. That Cannondale, whilst a thing of beauty, isn’t vastly different to the Tarmac, Melee, Propel, Emonda (to an extent). The differences are so small - yet it’s impossible to actually get time on each to form a view so a purchase is a bit of a leap into the dark. This is why your role, David, is so important as you get the chance to ride them all and can point out the differences beyond the marketing spiel.

True that only 10% of system weight is the bike. Also true that only 10% (?) of frontal area is the bike. I've never been sure how much of the benefit of an aero bike is how it forces the rider into a more aero position. For many of us middle aged folks who don't "slam their stem", do we get the touted benefits if we're riding in (relative to pros) a sorta "sit up and beg" position?

what I'd be really interested in would be a windtunnel test with the evo 4 to see whether it breaks the trend for tested aero bikes and actually beats the trusty old giant tcr with a real david on. Because as long as all the aero gains then don't exist in practice, the whole discussion of value really is a little pointless.

The good news is that if you’re not competing neither really matters

So that's the bike sorted. Now let's put a rider on it and some Cornish south-westerly cross winds, oh, and the hills and see what difference the areo bike makes then.

David Arthur, great talking point, but as soon as the video started we greeted by a Cannondale employee that was hired to make things more aero, so the talking point is weighted to YES, its important, so buy this LAB71. Seems like a good discussion away from any bike manufacturer location.

The fact that seems missing is that the rider's body will have more wind drag than the bike.

Great discussion thanks for posting. It’s especially good to hear assertions that aerodynamics outweigh weight except on the steepest slowest climbs. (Power to overcome air drag increases with the *cube* of one’s speed.) I especially noted Nathan’s point that it’s weight of bike AND rider that matters, and we need to think in terms of fractions of total weight not only bike weight. Re frame geometry. A teardrop shape with a 4:1 to 6:1 length to width ratio dramatically reduces drag compared to a cylindrical tube. Anything less than that, and the drag remains close to that of the cylinder. It’s not at all a linear progression. There are certainly design tradeoffs and practical considerations, but it’s important to understand that a non-round tube with a 2:1 ratio or so isn’t changing things much from a drag standpoint. Last point-with spoked wheels or even wheel coverings, a tremendous amount of drag comes from the fork. No matter how teardrop shaped, the turbulence between the fork blades & wheel is astonishing. Same reason why monoplanes are much faster than biplanes. As Mike Burrows asserted, monoblade forks are the answer. Front and rear. Like his spectacular Lotus 108. They’re probably not UCCI legal though.

Great interview. Good questions and insights. Thanks!

Today, I gripped the leading edge of my shopping basket, and rested my elbows on my handlebars, as I fought a headwind on my folding bike. So yes, I think aero is important for everyone, even if you're cycling to the shops! 😎

80 % of the drag is the rider more marketing it deepens on how fit you are and the prices are eye watering

Super interesting video. Thank you. 3 years ago I was deciding between a Propel and a TCR. The guy at the store said "if you live in Dubai where everything is flat, then go the Propel. But given we are in New Zealand with hills everywhere, the TCR with 1kg less, is a better choice." Given the aero advantages seem to improve as speed picks up, and I rarely get above an average speed of 30kph on a long ride, I went with the lighter TCR. But it's much easier to lose 1 kg of body weight than take 1 kg off the bike. So, if I skip my pie and chips for a while, I could buy the Propel and have the same weight to push up the hills... 😉

If aero is so important then why did they put disc brakes on their road bike? 😂

What an incredible interview, David! Informative, fun, and very well produced!

Great interview. Thanks

IMO, in the past 23 years, Cannondale has been the bike brand who have put out the LEAST amount of marketing BS. Agree that bike brands have hyped up aero too much, doesnt mean we should ignore it. Check out Cam Nichols timed runs of a System6 vs a Super6.

I just bought a new Orbea Orca Aero m20iltd. I love an aerobike. I like going fast on flat roads. Not really a climber. And I love the stifness of the frame on a descent. I had an endurance/climbing bike and I just couldn’t get used to it.

When it comes to aero, what a lot of tests on RU-vid show is that the slower you ride, the more time you save. This is because you actually spend longer getting from A to B so the aero benefits add up to more time saved. You don't have to ride at 45 kph to get the aero benefits even though that is often the speed quoted.

I believe 90% if not more drag comes from the person sitting on the seat. I have S works arrow handlebars And we always laugh as we're coming across the causeway in a 20 mile an hour Head wind I sure am glad that I spent big$$$$ On these aero bars😁

Great, thanks! More interviews with industry “brains” please!

Very pertinent discussion for my interests.

Going to the Nth degree to reduce aerodynamic drag then sticking a dirty great rotor and caliper right into the wind!😄

Hi David. Another great video, thanks. I'm convinced that aerodynamics matter even at relatively slow speeds, but what I continue to be less convinced of is whether changes in tube shapes and so forth are consequential. I remember at one point Factor claimed that they had designed their Factor LS gravel bike to put the rider in a very aero position, but hadn't worried about aero tube shapes (instead prioritizing weight). Their explanation was that at slower speeds it is really only the 'A' part of CdA that matters. A lot of us simpletons imagine that CdA is static but actually it changes depending on speed and wind direction. When you're going 50kph your CdA improves a lot when you replace a cylinder with a truncated airfoil, but at 20kph that difference is tiny and Cd will be similar regardless of tube shape. At 20kph you just need a bike that helps you reduce frontal area (ie: get your head down). Anyways, I don't know what I'm talking about or whether any of this is true, but I would love to hear what an expert has to say about it if you ever get a chance to look into this!

Very nice bike I saw it today and must say Cannondale has outdone itself again! But the delivery times are dramatic again, as is often the case with new models. And that's why I'm going for the Canyon ultimate slx 8. And fingers crossed that they are in stock at the end of June.

I think a comparison of body position drag reduction versus bike frame aero drag reduction would b more interesting unless you are selling bikes. Unless u are world tour rider w aero bike versus another world tour rider body position is free and makes a much bigger impact.

Great questions, David--Thanks for the excellent interview!

One doesn't want to blow one's own trumpet.....but one's own area of expertise is the most important.

11:47: But, that Trek though! 😍😍😍

A little perspective, you can expect a range from 1-4% range of total system efficiency gain going across a range of modern race bikes. Lets say in the case of the 250w output, the range would be 2.5-10w of power savings across a range of modern racing frame & forks. As the power increases, you can expect those percentages to expand a little due to the non linear characteristics of aerodynamics. But its not a free lunch as there are compromises as many engineering solutions never are compromise free. Aerodynamic frames tend to have frame performance compromises to a limited degree. Some of lateral stiffness reductions while conversely increasing longitudinal stiff. Depending on the compromise, the former might lead to a bike that doesn't track a line quite as well and the latter typically results in a harsher ride. Its a compromise made for extra performance in leading a break or finishing a sprint. Additionally, they are on average more challenging to layup and mold in carbon, but this is an issue for the manufacture and their quality control. Weight tends to increase, but unless the rider has been 'weight optimized', the minor difference in bike weight mostly results in a bike that doesn't feel as light on its toes and not much lost time during a climb. Lastly, the longitudinal stiffness can add to road chatter over poor pavement during a corner, but you can offset this to a degree with lower pressures by running tubeless. Running wider tires may reduce the overall aerodynamic performance, but the degree will be dependent on the system involved. While an aero bike typically will be quicker, it doesn't necessarily make the best ride or choice for every rider.

So, lets get back to the original question. Are Aero bikes worth it if you're not a professional cyclist?

is it suitable for off roads?

Glad to know my previous model Cannondale Supersix isn’t holding me back 😂

7 minutes of this CANNONBALL advertisement was all I could stomach, When the bike makes up (at best) 25% of the aero drag, improving that by a small % would seem to affect the people making the stuff's bottom line profits more than any actual performance improvement. I remember back-in-the-day being told "aero" wheels don't do much until the rider's going 30 mph...but a decade later somehow it was 30 Kph? Put two riders with similar body size/shape and power output on your "aero" bike with the other on something obviously "un-aero" and have 'em race off into a headwind and tell us how much difference it makes - just like when you see pros in races...the guy with the most slab-sided "aero" bike and wheels doesn't always win so how much difference does it all REALLY make?

I had a 2012 Pinarello. Only thing on it that was aero was the handlebars that I added. It weighed in at just under 7kg and was a great ride. I recently brought a 2022 aero bike which weighs 8.5kg. I did a local 30 mile ride that I’ve done many times on my Pinarello and my new bike knocked 15 minutes off my best time. The tubeless racing tyres would of added to the gains as well. It was night and day. My new bike is aero at the front and thin and light at the rear. Quite simply, aero brings more gains than a light bike.

I'd like to see bike manufacturers bring sub 8kg endurance aero bikes on to the market - best of both worlds!

I never used to give the aero engineering bike manufacturers trumpeted credit until I got an aero bike (long story) and now I’m a firm believer in its dynamics… doesn’t mean I agree with them costing the price of a small car…🍻

Just thinking if I buy a super aero bike then as I hurtle faster downhill I can get the maximum benefit from my hydraulic disc brakes by squeezing on them harder before I throw myself into corners😀

Please challenge me, how on earth can more arrow even be a factor when we have our bodies dragging at the highest point? Sorry but all I can think about is a sailboat and being against the wind. That's an exaggeration but I figured it would help simplify my point.

I have to say, for someone who just wants to sell his bike and tell me it's the best ever, this was a remarkably fun interview. Also the questions were chosen well to nurture that I think.

Go to 15:18 → the ‘cannnondale’ sticker is not aligned perfectly with the downtube (& its a demo bike, I believe). How can you call it quality frame if they get sloppy on one of the easiest job yet will instantly spotted? 🤔

People forget that with aerodynamic efficiency gains, a ~25km/h rider saves MORE seconds on a 50km ride than a ~40km/h rider. The faster rider merely saves more time as a percentage.

Evry 4 years Aero is everything, next 4 years weight is everything. Marketing

Its like asking the wolf to watch the sheep. Asking the engineer of a bike company that just designed a new aero bike his opinion on the benefits, hilarious. I knew in the first 2 minutes where this conversation was going. Real world benefits (minimal) concern the top 1 or 2 % of riders in the world.

I have a cannondale system six and for a bike, itself it is a fast bike but i got a much greater gain in average speed by wearing a speed suit, putting vision metron 4d mas bolt on tri bars on it and wearing an aerodynamic helmet, than the bike aerodynamics could ever offer on it's own. The biggest resistance to going faster, is the biggest object in the equation and that is you. So if your funds are limited, buy tri bars to put you in an aerodynamic position and an aerodynamic helmet and speed suit first, before spending big money on an aero bike but if your funds aren't limited the aero bike is the icing on the cake. Altogether my aero bike set up with TT bars, aero helmet and speed suit etc. is very nearly as fast as my proper all out TT bike, dressed for racing in the same manner. Of course i am a TT rider and like to train on all bikes in that position, a road racer would not put tri bars on but a road based aero helmet and speed suit would still benefit greatly, especially on breakaways etc. I am a little surprised however, that the aerodynamic equations the cannondale guy was considering, were about the bike itself and he didn't say anything about the rider and bike as an aerodynamic system together. That is where future aerodynamic gains can be made.

Nice bike from Canondale,one of the Best

Genuine question: would an aero seat post still help when you've got a saddle bag (as most weekend riders tend to)?

by the way is a beauty bike and the design is impressive. I wish we all could afford and have one like that but... is like that beauty has a $$$ price

I really dig that LAB71, it looks fast but, just how comfortable is it to ride, is it Atheos comfortable?

the largest aerodynamic obstacle isn't the bike, and aero gains there are helpful, but compared to YOU the rider, as a big non-aero bag of water, and the aero your bike 'saves' doesn't change that very much.

I can never understand why fairings, i.e. non structural parts cant be added to a frame so that it might look like a System 6 but have a light frame, They do this in every other wheeled sport, and aircraft.

Most races I do these days average high speed. B grade which I race in averages 44kmph and c 43 and d averages from what I’ve seen around 40. Aero bikes still matter

Here's a little napkin math. No speed factor, so an artificial assumption that speed doesn't matter and I'm always going 20mph (or any other speed). To simplify, we'll say all the watts are working to over come drag, though it's probably just 90%. Everything I've researched says that about 80% of the bike/rider drag is the rider. So if I'm pushing 200 watts, 160 watts of that is me and 40 watts is the bike. If I could cut the drag of my bike in half, I could theoretically go 20mph pushing only 180 watts. Saving 20 watts (10%) certainly isn't nothing. But in reality, I can't cut my bike's drag in half no matter what I do. I can save 25% or so, tops. So instead of that theoretical 20 watts, I can really save just 10, down to 5% of the total of me and the bike. Going back to that 90% and adding back 10 watts for rolling resistance and drive line friction (which more appropriately would have come of the top), I'm not getting much out of my effort to make my bike more aerodynamically efficient. I'd be far better off working on my fitness and flexibility so I can hold an aero posture for longer.

Why is the wheelbase elongated?

You might need a couple of grams extra to be more aero that you don't want for climbing but consider you tend to ride a lot of flat between hills so when you get to the hill, more aero is less tired is more energy for the climb. I like the square biddons. Thats attention to detail. Pity the cages aren't faired in though.

If aero is everything and 1 kg of total mass penalty does not count, how on earth this bike is better than SystemSix? Why did Specialized discontinue the Venge and tries to fool us with Aethos?

Why do all these brands make these bike compliance with such big tires. It's nice to have options, but how many people buy a roadbike and put bigger than 28mm on? The gap between front tire and downtube and rear tire and seatpost can be much smaller for improved aerodynamics. For example as you can see between the SuperSix and Systemsix.

3:10 which road is that? Looks a bit like Wrynose to me. Mind you, I've suffered up several hills that look similar. I'm guessing at 3:33 it's Hardknott. I've walked that a couple of times. 🤣🤣

I mean we already know what the answer is going to be when the Cannondale engineer/employee is going to discuss aerodynamics and if they are really valuable for the “regular” cyclist. Lol. Of course it is.

so many nice bikes.... decisions!

Body position most important

Drag is not proportional to velocity, it is to the square. I do wonder how qualified bike designers really are....

First your positioning. If you've optimized that, you save watts by riding an aero bike. But I doubt very much most rider can ride that position.

Same argument that goes for the weight also applies for aerodynamics: the rider is the biggest body that you are pushing through the air. So why does he use this argument for weight and dismisses it for aero?

Aero is everything even for casual rider, makes the ride easier and faster. I noticed it when I changed my wheel to aero wheels 😁

Lightweight bikes for going uphill, aero bikes for straight areas (no hills, mountains).

Sure sell that $8k - $10k price tag bike for maybe going up a hill 20 - 30 seconds faster. It does not make sense. You want to make yourself aero, stop riding always of top of the hoods. Work on your flexibity and try to stay in the drops. Try to get low and you will see the benefits. You will save yourself a whole lot of $$$.

If you ride 15mph into a 15mph head wind you are getting bucket loads of wind. No need to be going super fast to get results from aero.

Personally yes, my Venge flatters my very mediocre ability 😊 (definitely faster than my S Six Evo)

All the group rides where I live are slow on flat ground and only go hard on climbs. If I accelerate 1kph, then no one follows me. So aero doesn't count for these people, which is consistent with their position on the bike, which is not at all aero.

No difference if u riding as a group. Most of us will draft each other. Unless u r doing solo TT.

lets get a guy from cannondale to tell us if spending 10k on a cannondale is worth it. hehe

Absolutely not just another marketing con by the industry to get you to buy another bike that you don't need.

how many % of system aero drag come from the bike? may be even no more than only one of your arm.

Considering weight as a system, but excluding aerodynamics from the same, is a false comparison. Just like shaving grams off a bike that will be ridden by a 200+lbs rider is worthless, so to are marginal aerodynamic gains on a bike ridden by someone with a 36+ inch gut. Most people, esp in the west where these bikes mostly sell, are simply not fit enough to be bothering with aerodynamics.

the average rider can't maintain an aggressive position that these bikes require.

Most aero is probably the clothes. With cycling clothes i was 2km/h faster than I was with a windcathing jacket.

David sitting there just nodding knowing there is 1W difference between the all aero Madone and his TCR at 30 km/h 😂

Then why are people not riding faster when they get an aero bike?

My local cycling group restricts the rides to 12 to 15 mph yet they are all using deep rim carbon wheels lol

cannondale needs to learn how to integrate that cable in the stem, Chinese cheap brands have way better implementation of internal cable routing.

Maybe cut back on the pizza and beer? You’ll save money and ride faster with a smaller belly and by losing 10-20 lbs. Then once you’ve addressed your own shortcomings, maybe focus on the bike frame?

So you interview a aero bike designer to evaluate whether an aero bike is faster.

Is Aero worth it? Listen to our independent expert who is selling a Cannonsale SuperSix 😅

15k... I will keep my Caad 10

Todays cycling industry is somewhat similar to mobile phone industry. Add few tweaks charge a bomb and voila you have a winner. All look the same i think maybe iam wrong.

bike a small part of the system for aerodynamics too, not just for the weight.

99% of the people don't race, if you don't race you don't need aero. Don't ask a representative of Canondale, he will always tell you to change your non aero-bike and buy an aero. It's business, nothing else, it's money in the pocket of the producers. It just looks sexier, and that's an argument to buy an aero-bike. Most people have a lower speed average than 30 km/h, and in this 90% category the advantage for an aero is a few watts.It's the biggest lie in bike industry, to tell a non professional biker, that he needs an aero bike to be substantially faster, all bull shit.

Great so why do I need this bike? It just seems like cannondale are just playing catch up with specialized tarmac sl7…also he trashes the weight weenies argument but then says it not as fast as the system six?!

Any advantage of aero is negated at every traffic light. We don’t ride on closed roads

If they are trying to make the bike as aerodynamic as possible, why did they make it with disc brakes???

Would be nice if you could actually get hold of one :(

Come on!! Dont talk to a bike manufacturer, talk to unbiased engineers. What is the resistance from the body vs that of the bike? 90/10? There may be a slight advantage in an aero bike on a solo ride, but it would be negligible when drafting on a group ride. The industry is exploiting pseudo science, and the consumer need to have the latest and greatest.

Buy what you Like.

The human on the bike is by far the largest mass to carry, and the biggest silhouette to push through the air. I have a difficult time believing that an aero bike alone can save 10% of energy. Wind tunnel tests are fine, but in the real world there are head winds, cross winds, tail winds, and pacelines. This guy works for Cannondale. He has an agenda to sell Cannondales. While the video is interesting, and a lovely ad for Cannondale, this discussion is sort of meaningless for me because I'll never spend $15K on a bicycle. I wouldn't even spend $15K on a car.

And then you plop a human on the top of the aero bike, and all gains are gone. I don’t get it. The giant mattress on the top of the bike is not addressed

2 bikes you need, aero and mtb. That covers everything.