More aerodynamic bikes, rather than lighter bikes, dominated the 2025 Tour de France, signaling a significant shift in cycling technology and strategy.

This evolution in bike design emphasizes a significant trend. While riders have long fetishized lightweight bikes for their ease in climbing and quick acceleration, recent advancements and race results have shown what the experts have long shouted: that aerodynamic efficiency usually has a greater impact on overall performance.

This domination may have you asking yourself: Should my next drop bar bike be aerodynamic? This guide will help you decide.

bmc teammachine r 01

The Aero Bike Defined

Almost every high-performance race bike today has details that reduce its aerodynamic drag. An example is hidden routing. While fully hidden routing looks aesthetically pleasing, its primary performance benefit is the aerodynamic gains it provides.

So, it can be confusing when cycling editors like me reference “aero bikes” because one could rightly ask, “Aren’t all race bikes today aero?”

Let me, hopefully, offer some clarification. When I/Bicycling refer to an aero bike, we are talking specifically about race bikes consciously designed to prioritize aerodynamic drag reduction ahead of almost every other attribute.

Here is an incomplete list of aero race bikes:

BMC Teammachine R, Canyon Aeroad, Cervelo S5, Colnago Y1Rs, Giant Propel, Orbea Orca Aero, Ribble Ultra Aero, Ridley Noah Fast 3.0, Scott Foil, Stromm RAKTT, and Van Rysel RCR-F

All-around race bikes, meanwhile, do have some aerodynamic tuning, but the design brief for these frames places a much greater importance on keeping frame weights low.

specialized tarmac sl8

Here is an incomplete list of all-around race bikes: BMC Teamachine SLR, Cannondale SuperSix Evo, Canyon Ultimate, Cervelo R5, Colnago V5Rs, Giant TCR, Orbea Orca, Pinarello Dogma F, Ridley Falcn RS, Scott Addict, Specialized Tarmac, Trek Madone, and Van Rysel RCR.

Essentially, aero race bikes are heavier but more aerodynamic, while all-arounder race bikes are lighter but less aerodynamic. But the lines that separate aero from all-arounder are blurry and ever shifting, and there are a few bikes that don’t neatly fit into either category.

When Less Weight Is Faster

Everyone, or almost everyone, loves the way a light bike feels. They feel so lively and reactive to every little movement that they telegraph speed and performance in a way nothing else can.

I’ve also heard it argued (but not seen it proven) that, all things equal, a lighter bike is smoother over bumps than a heavier bike. And based on my long career testing bikes, I do think there’s something to that argument. But that’s a topic for a different story.

Light bikes feel so good and so quick, it’s easy to understand why people love them and are convinced that they’re faster than a heavier bike. But feels like isn’t always the same as actually.

There is only one situation where a lighter bike is faster than a heavier and more aerodynamic bike: A steep and slow climb (and only the climb).

And even then, the steepness of the climb and the speed of the rider must be factored into the calculation. On the same climb, a less powerful rider may be faster on a lighter bike, while more powerful rider might be quicker on a heavier but more aerodynamic bike. Wind speed and direction can also swing the advantage one way or the other.

Scott Addict RC Pro

The advantage of a lighter bike on a climb is often overstated, since in reality, even a notable weight difference between bikes doesn’t result in a much faster climb. I’ll use the Hautacam, a decisive climb in this year’s Tour de France as an example.

Hautacam is about 13 kilometers (about 8 miles) long with an average gradient of 7.8 percent. Our example rider weighs 155 pounds and is pedaling at a consistent 200 watts (2.84 W/kg).

Riding a 14-pound bike, they would complete the climb in about 1:13:22.

If they rode an 18-pound bike, they would reach the top in about 1:14:57.

So, riding a bike that’s four pounds (a lot) heavier would slow our rider by about 95 seconds (2.14 percent). That’s a lot of you’re a professional racer or chasing a Strava KOM, but it’s insignificant to civilian riders like you and me.

Note that this is a very simplified example and does not include wind conditions, nor any aerodynamic difference between the bikes.

When More Aerodynamic Is Faster

In contrast to a lighter bike’s benefit manifesting only during an uphill time trial, a heavier and more aerodynamic bike is beneficial (almost) everywhere.

“Weight only becomes a significant factor during steep climbs. However, even on hilly routes, aerodynamic efficiency often plays a larger role in overall speed and performance,” says SwissSide, a leading aero consultation and design outfit.

You can think of improved aerodynamics as being faster for the same power, using less power to maintain a certain speed, or saving energy over time.

It is true that the faster you ride, the percentage of your power needed to overcome aerodynamic drag grows. But this is often misconstrued as “aero bikes only benefit faster riders.” At every speed, a rider is always working against air resistance. Even as slow as 10 mph, half of your total power is used to overcome air resistance.

So, there is never a situation where aerodynamics don’t matter, and there is one limited situation (steep climbing) where weight is a more significant factor than aerodynamics. But even in that one situation, aerodynamics still matter.

climbing

When you consider the entirety of a typical ride that includes flat sections, climbs, and descents, a more aerodynamic bike is always faster.

To address the weight versus aero debate, [SwissSide] modeled different bike scenarios on stage 11 of the 2021 Tour de France. This stage featured four categorized climbs before reaching the final ascent of the HC Mont Ventoux (15.7 km at 8.8 percent). Notably, though, this stage did not conclude at the summit but featured a descent down Ventoux to the finish.

And in their calculations, a solo rider—assuming Tour-level speed and power—would be 19 seconds faster up the Ventoux climb on a 1,000-gram lighter bike. However, for the whole 199km stage, the rider on the 1,000 grams heavier, but more aerodynamic, bike would be 3 minutes and 16 seconds faster.

In a tidy summary, SwissSide proclaims that, for professional riders, the average gradient for the entire ride needs to be 7.5 percent—meaning 7500 meters / 24,000 feet of climbing per 100 km / 62 miles—before weight becomes more important than aerodynamics.

For us non-pros, the gradient drops to 4.5 percent (4500 meters / 14,764 feet of climbing per 100 km / 62 miles) before weight becomes more critical than aerodynamics.

Aero Bikes and Comfort

Other than the additional weight, traditionally one of the biggest drawbacks of an aero race bike — compared to a lighter all-arounder — has been a harsher and less compliant ride.

From my bike testing experience, I can say that was true in the first generations of aero bikes. However, today’s aero bikes ride nothing like the first generation of aero bikes.

orbea orca

Improved design and carbon layups in combination with wider and lower-pressure tires have significantly narrowed the comfort gap between an aero bike and an all-arounder. Today’s aero race bikes are surprisingly comfortable.

However, even modern aero bikes usually feel a bit stiffer and less refined than an all-arounder. According to my conversations with brands that supply frames to top pro cycling teams, this difference in feel alone is often the main reason a rider chooses an all-rounder over an aero bike. Still, some riders prefer the extra feedback that an aero bike provides.

BKE

The Fit Issue

More than anything, how race bikes fit may have a larger impact on your decision than any factors related to weight or aerodynamics.

Both aerodynamic and all-around race bikes have, no surprise, a race bike fit. Their geometry is designed to help riders fold into a flat-backed riding position.

Meanwhile, frames designed to put riders in a more upright riding position tend to have less focus on aerodynamic frame details.

There Are Cheaper Ways To Get Aero

No matter your position, there are still ways to reduce your drag, which will improve your speed and efficiency. You can realize aero gains without investing in an aero bike or other expensive purchases like wheels.

Your body and your riding position have an exponentially greater impact on your overall drag on the bike than the frame and wheels.

You can realize huge aero gains with your current bike simply by working on sitting in a more aerodynamic riding position on the bike, making yourself smaller, or with aero-optimized apparel and a helmet.

cervelo s5

Should You Ride an Aero Race Bike?

This is a tricky question to answer.

You see, today’s all-around race bikes like the Tarmac, Madone, and SuperSix Evo are quite aerodynamic too: They’re just less aerodynamic, but lighter, than aero race bikes like the S5, Noah Fast, and Y1Rs.

Meanwhile, today’s aero race bikes are pretty light, so even if you’re not a pro bound by the UCI’s 6.8Kg minimum bicycle weight, you’re still looking at a small weight difference—when equipped with the same parts—between, for example, Cervelo’s all-around R5 and aero S5.

So, the question isn’t: should you ride a bike that’s much lighter but not aerodynamic or an aerodynamic bike that’s much heavier? The real question is: do you choose a bike that’s slightly heavier and more aerodynamic, or a bike that’s a little lighter and less aerodynamic?

If you mostly care about speed and efficiency throughout an entire ride, you should probably go with the aero bike.

If you mostly care about climbing speed and a refined ride quality, you should probably go with the all-arounder.

But in reality, contemporary race frame designs have focused on optimizing both weight and aerodynamics, and they all ride quite well, too.

It’s not about what’s better or faster; it’s about feel and what you prioritize more. Because when you buy a modern race bike, it will be both light and aerodynamic regardless.