Is an aero frame worth it?

[maxim809]

I've purchased off-the-rack aero bikes and gotten slower because the stock integrated bar/stem isn't optimal for my fit.

And especially back then, it was a whole thing trying to get narrow bars with long reach. Many manufacturers didn't even offer combos like 40x120 or 38x130.

You're right, TT'ing is the truth. And all my Merckx TT's on the aero bike with stock cockpit was significantly slower than my regular bikes with optimized fit. Normalized for wind and air density.

So, I guess you can say it's noticeable when you're slower.

Lessons are to:
1. Budget for the 1-piece swap if the brand doesn't offer a choice to swap at time of purchase.
2. Plan for some cable rerouting; complexity based on details of the build.
3. Really understand the fit you are after, or budget for some more time/cost for iterations.
4. Maybe build frame-up, but point 3 still stands if going for 1-piece.

[Steve Curtis]

The lines between frame sets are constantly being blurred by manufacturers making niches.
I don't see this as a bad thing, as you can choose your blend of aero, comfort, tyre clearance etc to fit your needs, or wants.

I'd no longer bother with a full aero builds as I know wider tyres allow me to be full committed more of the time on the shitty roads I ride. Particularly descending or under trees where you can't read the road for the debris or holes that could kill a skinny 23/25mm.


Anyway, my point is choose the level of aero you want in the overall blend of the bike, but don't buy a full aero build in the hope you'll suddenly be super fast. If you can't get into , and hold a good position it's wasted and you'll probably be uncomfortable trying to make it work.

As always, a well fitting bike regardless of style will always be faster and more enjoyable than a aero frame that doesn't fit.
If you can get the fit right then you'll be a bit more efficient.

[frostorama]

Having read this thread I went back to review my annual average speed from when I was riding a Cervelo S3 with Zipp 303's to my current Aethos with Alpinist CLX wheels. Not scientific by any measure but the difference between the aero and non-aero bikes for me over a year is that the Aethos is 0.5kph slower than the S3.

I suspect the difference is likely to be down to the wheels and aero shaped bar on the S3 and perhaps a very small percentage in the frame shapes.

However I would say the Aethos is so much more comfortable, handles better and of course climbs quicker. I have been able to enjoy 300km single day rides that I would never consider riding on the S3.

[AJS914]

I'm sure someone will jump in and fight me, but I have never, ever seen anyone buy an aero frame and actually be faster. They'll say it's faster, as all of us do when we have to mentally justify something we just invested in and want to believe is going to benefit us, but the ride data never proves it, and they're never suddenly able to do something out on the road they couldn't do before. From crits to time trials (which don't lie, btw), the ability of said rider never changes bike to bike. I've bought aero wheels, aero frames, handlebars, etc. and none of it made me faster. snip The other 99.5% is fitness.

Why do people persist with the aero denialism? Obviously aero equipment is faster. The data tells us it is. But you can't see it with your eyes because the differences are small - a few minutes over 100km or 1M farther ahead in a sprint. It's not going to turn an average joe into a world champion or even a local podium winner.

I think we've also been experiencing an arms race even at the local level. The first guy that got some aero wheels had an advantage but now everybody in the club or local race has them. So if you are the guy without some aero game, you are at the disadvantage. Any aero stuff you buy just brings you back to the baseline these days. If you go all out with aero - best wheels, aero super bike, integrated bars, skinsuit, etc. then you might have a small advantage over the guy in your club that just has 50mm wheels and an aero helmet.

My only aero game is wheels, helmet, and race fit jersey on an otherwise not at all aerodynamic Colnago C59. Going down a steep local hill against friends without aero wheels, I rode away from them without pedaling. I was probably 20 seconds ahead at the bottom which is a far distance at 45mph down this hill. Aero gains are real but they don't turn you into a champion.

Dan Bigham just broke the hour record because of his amazing ability to aero optimize. He didn't get that world record because he has the biggest engine in the world tour. He's not even in the world tour!

[Steve Curtis]

[/quote]

Going down a steep local hill against friends without aero wheels, I rode away from them without pedaling. I was probably 20 seconds ahead at the bottom which is a far distance at 45mph down this hill.

[/quote]

Being heavy will give the same results

[spdntrxi]

Going down a steep local hill against friends without aero wheels, I rode away from them without pedaling. I was probably 20 seconds ahead at the bottom which is a far distance at 45mph down this hill.

[/quote]

Being heavy will give the same results
[/quote]

this is me regardless of bike.. aero/non aero. Friends that weigh the same I still drift away from with no issues.

[Robius]

In my experience my average speed went up about 1.5-2kph from Giant TCR to Felt AR2 (30-31kph to 32-33kph). They have a very similar geometry and I ride the same cockpit and wheelset.

The only difference is that I'm now using aero bottles because AR2 frame isn't designed for round bottles at all.

[wltz]

55-deep aero wheels vs 38-deep climbing wheels (+ marginally faster rolling tyres) increase my average speed by 1-1.5 kph on the same bike and wearing the same kit. Aero gains are real.

[Nickldn]

I'm sure someone will jump in and fight me, but I have never, ever seen anyone buy an aero frame and actually be faster. They'll say it's faster, as all of us do when we have to mentally justify something we just invested in and want to believe is going to benefit us, but the ride data never proves it, and they're never suddenly able to do something out on the road they couldn't do before. From crits to time trials (which don't lie, btw), the ability of said rider never changes bike to bike. I've bought aero wheels, aero frames, handlebars, etc. and none of it made me faster. Like everyone else, though, I did go out on the first ride with said purchases and ride my nose into the dirt trying to prove to myself it was worth it, but in the end, it was just vanity. Race tires, a proper tune-up top to bottom, quality bearings throughout, a good position, and tight-clothing is what mechanically differentiates speeds among riders. The other 99.5% is fitness.

It depends on your riding speed. If you don't ride any of your segments at over about 20mph, then aero equipment will not provide any actual gain.....it may even make you slower due to the weight.

[AJS914]

It depends on your riding speed. If you don't ride any of your segments at over about 20mph, then aero equipment will not provide any actual gain.....it may even make you slower due to the weight.

People keep repeating this but it's just not true. Aero gains are aero gains at all speeds. Slower riders actually save more time on a given course than the faster riders.

Now you can debate whether any aero equipment is worth paying for if you are an 18mph smell the roses, stop every 5 miles type rider but that is a separate discussion.

Did a search to find a chart where someone has sorted this out. The slower 150 watt rider saves over 8 minutes on this 100 mile course. The faster 300 watt rider saves around 6 minutes.




https://blog.trekbikes.com/en/2020/07/1 ... ly-matter/

[Nickldn]

It depends on your riding speed. If you don't ride any of your segments at over about 20mph, then aero equipment will not provide any actual gain.....it may even make you slower due to the weight.

People keep repeating this but it's just not true. Aero gains are aero gains at all speeds. Slower riders actually save more time on a given course than the faster riders.

Now you can debate whether any aero equipment is worth paying for if you are an 18mph smell the roses, stop every 5 miles type rider but that is a separate discussion.

Did a search to find a chart where someone has sorted this out. The slower 150 watt rider saves over 8 minutes on this 100 mile course. The faster 300 watt rider saves around 6 minutes.




https://blog.trekbikes.com/en/2020/07/1 ... ly-matter/

Aero gains increase at the square of speed. Below about 18mph there is not much to saving to be made.

I never understood how the 'slower rider saves more time with aero kit' marketing mantra works with physics.

It would be really helpful if could you please explain how the chart you have added relates to this basic fact of physics. I don't think the article you linked explains it. It does publish some graphs seemingly based on testing, but I think it is very difficult to understand and reconcile these graphs and the message in the article with basic physics.

The fact is most amateur riders haven't got a lot faster by buying an aero bike. Sadly Trek's expansive and expensive marketing isn't going to change this reality.

[TobinHatesYou]

What is there not to understand? The slower rider is not saving more time as a percentage of his original time…he/she is saving more seconds, period. If one person takes 5 hours to complete a century while another takes 4 hours on the same non-aero bike, you give them both an aero bike and the first person is going to both save more time and still finish just short of an hour later.

[Hexsense]

Aero gains increase at the square of speed. Below about 18mph there is not much to saving to be made.

I never understood how the 'slower rider saves more time with aero kit' marketing mantra works with physics.

Feel free to point out any flaw in my example. Many calculation is based on http://bikecalculator.com/

84 km course.

A rider going at 28 km/h (doing 112.5 watts) would finish it in 3 hours.
B rider going at 42 km/h (doing 332 watts) would finish it in 2 hours.

Give both an aero bike. Assume the 42 km/h rider save 3% of his power, 28 km/h rider save 2% of his power.
Lets add free watts into the power and calculate back the speed.
112.5*1.02 = 114.75 watts which is 28.24 km/h. In other words, 2% save of watts makes it 0.8% faster at 28 km/h.
332*1.03 = 341.96 watts which is 42.48 km/h. In other words, 3% save of watts makes it 1.1% faster at 42 km/h.

Then

A rider would finish the course in 84/28.24= 2.974 hours. It's a save of 1.5 minutes from his 3 hours ride.
B rider would finish the course in 84/42.48= 1.977 hours. It's a save of 1.3 minutes from his 2 hours ride.
And 1.5 minute is more than 1.3 minute.

[AJS914]

It would be really helpful if could you please explain how the chart you have added relates to this basic fact of physics.

Nick, you'd have to study physics first. Aero gains are real at every speed. Please, people stop saying they kick in at a certain speed. It's just not true.

The fact is most amateur riders haven't got a lot faster by buying an aero bike.

I even said this in my post. If you are an 18mph smell the roses rider, a $2500 set of wheels or a $15,000 aero bike is probably not worth it just for speed gains. But you may like the color of that bike or the look of those wheels!

Is saving 8 minutes over 100 miles worth it? That is a value judgement based on one's bank balance. One could also make the case that saving 6 minutes for the 300 watt rider also isn't worth it. We could extend that to say that it's only worth it if you are making the podium at a major professional race otherwise you wasted your money to go a little bit faster.

In any case, I don't care whether people think aero equipment is worth paying for. I don't care at all. I'm just tired of hearing fake news like 'aero gains don't kick in until a certain speed'.

[StanleyM]

... Aero gains are real at every speed. Please, people stop saying they kick in at a certain speed. It's just not true.

Messing with datalogged coastdown tests from about 20 mph, I see aero differences above about 8-10 mph. And solidly above about 12mph as run to run variations, tiny breezes and more get swamped. Small amounts at first of course, just saying they kick in for sure. By around 17-18 mph they predominate over tire and bearing rolling resistances it seems.