First review: New Cervélo S5 Ultegra Di2 2023 – The greatest aero bike of all times?

Simplify, refine, improve – the Cervélo S5 2023 is intended to be more of an evolution than a revolution. The goal: to make the bike even faster and, above all, to take dealer and user friendliness to a new level. We already had the S5 Ultegra Di2 on test before the launch and tell you how it works.

GOAT – this does not refer to an animal, the initialism stands for the “greatest of all times” and is often used to describe someone who is the best of all time in their sport. In cycling, names such as Eddy Merckx, Peter Sagan and Mark Cavendish come to mind.

The 109th edition of the Tour de France has just finished in Paris. Anyone who watched the race will inevitably ask themselves the questions: Is Dane Jonas Vingegaard who snatched the yellow jersey from the seemingly invincible Tadej Pogačar the future GOAT? Or is it Wout van Aert after all, who gives the impression that he could win not only the green jersey, but all the other jerseys as well, if only he wanted to.

With all the top performances, however, a few onlookers might have noticed that Team Jumbo-Visma riders were on a new generation Cervélo S5. This is also due to the fact that the visual innovations on the bike are very restrained. This is in stark contrast to the bike’s performance – three of Jumbo-Visma’s six stage wins have come on the Cervélo S5 2023. Chapeau! That’s also the answer to the question of whether the new aero bike is fast and immediately raises the next question: Is it also a GOAT? Is it the fastest aero bike ever? We already had the Cervélo S5 Ultegra Di2, which costs € 9,699 and weighs 7.5 kg in size 56, on test and answer not only this question, but also how the bike behaves when it’s not powered by calves à la Wout van Aert.

Details and Specs of the new Cervélo aero bike

How come the pros from Team Jumbo-Visma have been riding the new Cervélo S5 for a few months now, but hardly anyone noticed the difference, at least in the TV race broadcasts. Quite simply, visually the changes are very limited. Cervélo is now taking full advantage of the UCI’s design rules here and making the frame triangle more flat overall. This is particularly noticeable in the area of the head tube and the bottom bracket. In addition, the tube shapes change and become sharper-edged, especially in the area of the down tube and the seat tube. There are also changes in the shape in the area of the fork front and the dropouts.

Overall, you have to put the new and the old model of the S5 directly next to each other to see the visual differences. More obvious differences, however, are hidden and should significantly improve the handling of the bike – especially during assembly and service. For example, all sizes of the bike with all stem-handlebar combinations now come with the same set of bolts for assembly. The infamous dealer kits for the different sizes of the predecessor model are eliminated.

Cervélo has also worked on the stem-handlebar combination itself. This should allow for a flatter transition between the handlebar and brake lever. In addition, the handlebar can now be freely tilted between 0 and 5 degrees. If you look at the bike from the front, you’ll also notice a slimmer head tube and more tire clearance. The Cervélo S5 offers space for tires up to 700x34C and then has 4 mm space left on the left and right.

The Cervélo S5 is available in a total of four different versions, two with SRAM and two with Shimano groupsets. All versions come with the characteristic Y-stem called Cervélo ST35 Carbon, the matching Cervélo HB14 carbon handlebar and the new Reserve 52|63 wheels. These were specially developed for the new Cervélo S5 and come with exciting details. In addition, all versions feature the Vittoria Corsa TLR Graphene 2.0 tires in 700x28C and the Cervélo SP20 carbon seatpost. The differences lie only in the shifting groups. Here, the choice is between Shimano DURA-ACE Di2 or Shimano ULTEGRA Di2 and SRAM RED eTap AXS or SRAM Force eTap AXS, so the Cervélo S5 2023 is only compatible with electronic gears and hydraulic disc brakes. Those who want to put together their own bike can also opt for the frameset.

Model	Groupset	Gear ratio	Wheels	Price
Cervélo S5 Shimano Dura-Ace Di2	Shimano Dura-Ace Di2	52/36 T x 11–30 T	Reserve 52|63	€ 12,999
Cervélo S5 SRAM Red eTap AXS	SRAM Red eTap AXS Power	48/35 T x 10–33 T	Reserve 52|63	€ 13,499
Cervélo S5 Shimano Ultegra Di2	Shimano Ultegra Di2	52/36 T x 11–30 T	Reserve 52|63	€ 9,699
Cervélo S5 SRAM Force eTap AXS	SRAM Force eTap AXS Power	48/35 T x 10–33 T	Reserve 52|63	€ 10,199
Rahmenset	–	–	–	€ 5,499

The geometry of the Cervélo S5 2023

The bike’s geometry is sporty and compact, as befits a race bike in this category. All geometry data can be found in the table.

Size	48	51	54	56	58
Top tube	520 mm	535 mm	550 mm	565 mm	581 mm
Head tube	66 mm	84 mm	106 mm	127 mm	154 mm
Head angle	71°	72°	73°	73.5°	73.5°
Seat angle	73°	73°	73°	73°	73°
Chainstays	405 mm	405 mm	405 mm	405 mm	405 mm
BB Drop	72.5 mm	72.5 mm	72.0 mm	72.0 mm	67.5 mm
Wheelbase	973 mm	974 mm	975 mm	982 mm	999 mm
Reach	367 mm	376 mm	384 mm	392 mm	401 mm
Stack	496 mm	519 mm	542 mm	565 mm	588 mm

The new Reserve 52|63 wheels of the Cervélo S5

For the wheels, Cervélo is breaking new ground and developing them together with the in-house wheel builder Reserve specifically for the Cervélo S5. So instead of the bike and wheels being created separately and then assembled, they are developed together as a system. That sounds quite sensible for such a complex product. There are some exciting details hidden in the wheels themselves. For example, the inner rim width is as large as was recently unimaginable in the road sector: 25.4 mm at the front and 24.4 mm at the rear. Both are thus optimized for the use of voluminous 700x28C tires.

Such wide tires come as a surprise on an aero bike, but should provide less rolling and air resistance. There’s nothing new to report regarding the combination of a flatter and wider front wheel and a higher and narrower rear wheel, which should achieve the optimum between the low susceptibility to changing winds and low drag. We already know this approach from the Roval Rapide CLX. Interesting are the asymmetrical shape of the rear rim and its holes for the spoke nipples, which are offset from the center. This aligns the spoke length and tension on the drive side and non-drive side, which should provide more stability.

The Cervélo S5 Ultegra Di2 on test

Admittedly, to be as fast as Wout van Aert, you also need the appropriate legs. Nevertheless, it is immediately clear from the first meters aboard the Cervélo S5 2023 what the bike is made for. Once the small weaknesses in the acceleration are overcome, which the bike carries around due to its not particularly low weight, then it goes forward mercilessly. The S5 shines with outstanding efficiency and is almost playfully fast. There is nothing left to be desired in terms of speed. You benefit most from the bike’s outstanding aerodynamics when the topography allows for a lot of speed. It is therefore also really fast downhill. However, the steeper it goes uphill and the slower you get, the more the aerodynamics fall behind the weight. Here, it is important to weigh up exactly when to switch to a lighter climbing bike.

The new Cervélo S5 has impressively proven how fast it is with three stage wins in the 2022 Tour de France!

On fast and technical descents, what is already apparent on the flat suddenly becomes crystal clear: the Cervélo S5 has razor-sharp handling that skilfully combines agility and precision, and implements all steering input very directly. What can be a bit of a challenge for newcomers makes experienced riders with an itch for an aggressive riding style shout for joy and promotes confidence in the bike and their own abilities. The downside of the handling is the design-related steering stop, which can cause nervous moments in tight corners in rare cases.

Comfort is not the most important criterion for an aero bike, so it’s neither surprising nor objectionable that the Cervélo S5 2023, like its predecessor, has a rather stiff frame that doesn’t generate the most comfort from the frame and attachments. The big advantage of the latest generation, however, is the combination of massive tire clearance and voluminous 700x28C wheels in a tubeless setup. Thanks to a lower possible air pressure, the bike’s vibration damping is top-notch and even smaller impacts are well absorbed. As a result, the Cervélo S5 comes with a good overall comfort.

Our conclusion on the Cervélo S5 2023

Whether or not the Cervélo S5 2023 is the GOAT among aero bikes will be shown in the direct comparison with the competition. In the individual test it convinces with a lot of speed, razor-sharp handling and pleasant vibration damping. This makes the bike not only an aspirant for ProTour victories, but also the right tool for anyone who wants to buy more speed on flat to undulating terrain for a lot of money. Those who ride a lot in the high mountains will find more suitable bikes in the Cervélo portfolio.

For more information on the Cervélo S5 2023 visit cervelo.com

---

Did you enjoy this article? If so, we would be stoked if you decide to support us with a monthly contribution. By becoming a supporter of GRAN FONDO, you will help secure a sustainable future for high-quality cycling journalism. Click here to learn more.

Words: Photos: Erin Nelson