Cervelo's new R5 is just 5.97kg but did the Tour de France Femmes rescue it from obscurity before it even went on sale?

The hierarchy of necessary race bikes is in constant flux. We’re told that what we need is a dedicated aero bike and another for the hills, only to be then redirected towards an aerodynamically enhanced all-rounder.

Then 2025 happens and the sharp-as-a-knife aero machine makes a surprise comeback, to the point that Tadej Pogacar leaves his featherweight climber on the roof of the team car, for the entire Tour de France, even the most hilly stages.

So where does this leave the climbing bike? Well, if you’re to believe Cervelo, the answer is, alive and well.

See, there was a counterbalance to Pog’s victory. At the Tour de France Femmes Pauline Ferrand-Prevot’s winning bike of choice was the new R5, a bike so light it looks like it needs to be tethered down, yet seemingly stiff enough to win at the sport’s highest level.

So how did Cervelo manage it, and in doing so, make the climbing bike relevant once more?

Every gram counts, in bike marketing at least

The headline accompanying the release of the new R5 is the claimed weight of 5.97kg. While Ferrand-Prevot’s bike was required to meet UCI weight regulations, the new model can be ridden by the rest of us in a sub-6kg guise that takes advantage of a frame and fork that weighs under 950 grams in a size 56. Just 650g for the frame alone.

This makes it approximately 100 grams lighter than the previous model, while the inclusion of updated components helps reduce the bike’s total weight by a claimed 326 grams.

There’s scant information in the press release about just how Cervelo’s engineers reduced the weight of the frame and forks but we do know from speaking to Cervelo’s Engineering Manager, Scott Roy that it’s been achieved via a combination of lighter carbon layup, revised tube shapes and some tweaking of the fixings. Certainly it looks svelte, cutting an elegant figure that its aero sibling the S5 could only dream of achieving.

One nice detail we did notice when we saw the bike in Lille, is Cervelo’s take on the now commonplace UDH hanger. It’s sleeker-looking, and nicely machined with a lower profile, saving a few more grams no doubt.

What we are told however is that the geometry has been altered to match the S5, albeit with a slightly lower bottom bracket height to help accommodate the R5’s 29mm tyre clearance. That means a size 56 has a stack and reach of 567.7mm and 391.1mm respectively.

Cervelo are more forthcoming when it comes to the component parts that contribute significantly to the new R5’s weight loss. The inclusion of the all-new HB18 cockpit is said to have resulted in a 150 gram drop, while adding some aero advantages, to the tune of two watts, according to Cervelo. The UCI-legal bar/stem combo comes in 15 different size combinations, and you get fitted via an authorised Cervelo dealer at no extra cost when buying an R5.

The R5 also gets its own wheelset, in the shape of the brand new Reserve 34/37 SL. Claimed to help drop another 60 grams from the R5’s total weight, they benefit from a revamped carbon layup that is lighter while still retaining the strength and stiffness of the outgoing hoops. The hubs are either DT Swiss 180 or 240 depending on the model.

That attention seeking 5.97kg bike gets the 180s and also benefits from the lightest groupset currently available, Sram’s Red AXS, although Cervelo are claiming the same total weight for the Dura-Ace Di2-equipped version too.

The two bikes below them in the range, come with the DT Swiss 240 hubs, and are offered in Force AXS and Ultergra Di2 builds. There’s also the option to buy the R5 as a frameset too, which includes the HB18 cockpit and the SP33 seatpost.

Weights for the other bikes mentioned were not available to us. But by our rough estimates, you add another 400g by opting for the Force groupset. The 240 hubset adds another 60g, over the 180's, so even the Force and Ultegra versions are likely to be well under the UCI weight limit of 6.8kg too.

So is the climbing bike here to stay?

So is the climbing bike back in favour with racing’s elite? The jury probably remains out, given that the men’s Visma|Lease A Bike team didn’t use the R5 during this year’s TdF.

Ferrand-Prevot’s success demonstrates that riders on smaller frames will still prioritise comfort over outright aero performance, while the men for now at least it seems, will continue to favour the stiffer aero bikes, even when the road points up.

For the rest of us though, where comfort absolutely should be one of our most important performance parameters, a featherweight race bike remains both desirable and practical. Indeed it can be argued that a bike light enough to balance on one finger and that’s designed to fly up the climbs a la Pantani, Contador or whoever your favourite climber was, is the reason that many turned to the road in the first place.

If the R5 is going to satiate those desires however, it will do so at quite the price. The Red AXS and Dura-Ace Di2 models retail at $14,250 / £11,500 and $14,000 / £11,00 respectively. The Force AXS and Ultegra Di2 models are $9,950 / £8,500, while the frameset option will set you back $6,500 / £5,000.