One bike to rule them all: why lightweight aero bikes are now THE essential race weapon

Just a few years ago, using an aero bike meant that pro cyclists and amateurs had quite the sacrifice to pay on the climbs. We’d see many Tour de France riders switching bikes depending on the terrain of the stage whereas now, putting time trials to one side, many riders will be on a single bike for the duration of the Tour. That's all down to the emergence of superlight aero bikes – or aero lightweight bikes, depending on which way you look at it. Are these new bikes really just as fast as the specialist aero road machines? And can we expect this trend to continue into the future?

The Specialized Tarmac SL7 (and the death of the Venge)

Let’s start with the most common bike in the pro peloton, the Specialized Tarmac SL7, as it’s a prime example of this phenomena. Three World Tour teams choose to ride the SL7, regardless of whether the stage is flat, mountainous, or somewhere in between. This wasn’t always the case though, as Specialized-sponsored teams used to have the choice between the Tarmac, a lightweight climbing bike, or the Venge, a bike that had aerodynamics as its primary focus.

So how come the SL7 managed to 'kill off' the Venge? It was a very successful bike after all, that didn’t sell badly either. 

> Bikes of the 2022 Tour de France

Specialized says that in its efforts to make the Tarmac more aero and the Venge lighter, the two designs ended up converging with such minor differences in performance that it was pointless to run two separate lines. In a pan flat 40km time trial, there’s a claimed 8-second (2.5W) difference between the SL7 and the 2019 Venge, and the latest Tarmac is just as quick as the Venge ViAS. That was a much heavier bike that sacrificed plenty of usability in its efforts to cheat the wind.

> Review: Specialized S-Works Sl7 Tarmac

So, in six years (the ViAS disc was released in 2016) Specialized has managed to cram just as much aero into a frame that’s 370g, or about 32% lighter… as well as improving the comfort, ease of maintenance and arguably the looks as well. Let’s take a look at what the other brands have been up to…

Colnago V3Rs (Also a bit of a do-it-all)

Another brand to adopt the ‘one bike’ philosophy is last year’s general classification winner UAE Team Emirates. Well, sort of anyway; most team riders can currently be seen riding the brand's V3Rs model and although Pogacar has been spotted using the yet-to-be-released ‘Prototipo’ it’s more than likely that this will be the V4R, and replace the V3Rs as the teams one-and-only.

> Colnago releases details about new Prototipo bike

Colnago says that this new bike, whatever it actually ends up being called, will need to be “as versatile as possible, suited to the needs of sprinters, rouleurs and climbers alike, and to be at the top in the different phases of a race.” If it didn’t think that this was possible then we would assume Colnago would still be making the Concept aero bike that was released in 2017.

Trek Madone... aero isn't dead just yet

A brand clearly not quite ready to kill off its aero machine just yet is Trek with the recent release of the 2023 Madone. However, once again we can see it beginning to converge with Trek's Emonda climbing bike, as it’s significantly lighter than the previous generation: around 300g in fact.

That means that the gap between the Emonda and Madone is down to about 260g, so it seems realistic that either the next Emonda is going to have to be lighter again or it’s going to become obsolete. We’ll be keeping a keen eye on just how many stages the Emonda gets used for.

> Trek unveils its fastest road bike ever - The 2023 Madone

Giant Propel (that kind of looks like a TCR)

A bike following a similar trajectory is the new Giant Propel… that could just as easily be a more aero TCR. It’s already got one stage victory under its belt, and we can see some pretty radical changes to tube shapes.

As this bike hasn’t actually been released yet there are no hard and fast facts or figures, but we presume the new skinnier seat tube and less beefy stem are an effort to shed weight, as the older machine was on the heavier side of aero bikes out there.

We paid particular attention to one Instagram user’s comment: “Propel in the front, TCR in the back.” 

> 2023 Giant Propel spotted

We couldn’t have put it better ourselves. Is there a chance that this is the end of the road for the TCR? We’ll see what that all-important weight stat is before prematurely condemning the TCR to the history books...

Scott Foil (aero is definitely getting lighter)

Another recent release is the 2023 Scott Foil, and you’ve probably got the hang of it by now: it’s lighter, faster, comfier etc.

> 2023 Scott Foil gets lighter, comfier and faster

For this one we do have some figures. The frame weight of 915g is extremely competitive for an aero bike, it's 9% lighter than the previous generation and now just 140g heavier than the Addict RC HMX SL. Once again, we’ll be interested to see just how much, or little, the Addict frameset gets used. We imagine less than ever before.

Pinarello Dogma F12 (The trendsetter?)

And finally, we’d be remiss to mention the topic without talking about the Pinarello Dogma F12. Pinarello’s F line is arguably the trendsetter in this whole thing, with the Italian brand having always been an advocate of a one-bike approach. You can’t say it’s not been successful either; under Team Sky and Ineos it’s won everything from the general classification in Grand Tours to one-day races and Classics.

Pinarello says that when designing a bike, it likes to have the desired goal of “maintaining the all-around” characteristic, which means a stiff and light bike, with excellent aerodynamic balance” leading to what the Italian company calls the “Pinarello feeling.”

> Pinarello launched Dogma F12 and F12 disc

Well, it seems like plenty of other brands are trying to get this feeling as well, although we somehow doubt they’d call it the same thing.

Conclusion

So, to answer the questions at the beginning then, what’s changed and how can all these aero bikes be saving such massive chunks off their weight?

Well, knowledge of aero philosophy has continued to evolve with most designs now using a Kamm-back design rather than heavier truncated aerofoils. Higher modulus (stiffer) carbon fibres are now used, which means that less material can be used to get the same stiffness; this also had a positive impact on frame weight.

There's also the rise and rise of electronics groupsets. They’re now the only thing we see on new top-of-the-range bikes, which gives designers more freedom as they don’t need to worry about sharp corners for cables to go around. This is also why we’ve seen such rapid adoption of integrated cockpits.

All of this, along with generational improvements and bikes being developed as a complete system rather than a standalone frame, means that aero bikes have shed some serious timber. 

Are they just as aero? The simple answer is yes. We don’t have a wind tunnel ☹ but manufacturers can’t lie about their speed and aerodynamic claims (although they can just choose the favourable data).

The new lightweight aero bike might not be faster outright, but the differences are so tiny that it’s negligible.

Will the trend continue? Personally I think that this depends a lot on the UCI weight limit remaining at 6.8kg. Teams are now perfectly capable of getting their aero steeds down to this limit, so why bother adding weight to a less aero climbing bike to reach the same figure? 

Whether this limit will change… well there’s long been speculation, but now seems as good a time as any. The UCI doesn’t seem quite so averse to change as in days of yore; for example, we saw the relaxing of some aero rules just last year.

> Find out what the UCI accredited sticker on your bike means

Are you a fan of the latest ‘do it all' bikes or would you rather a specific tool for a specific purpose? Let us know in the comments below…