Tested: Cervélo S5 aero speed weapon

The Cervélo S5 has a well-earned reputation as a speed weapon, so our regular scribe was interested to see if the next model is even better than its predecessor.

The original Cervélo S5 was launched in the lead-up to the 2011 Tour de France. Fourteen years on, it remains one of the most feted aero road bike platforms on the planet thanks to a long and bountiful partnership with Visma-Lease a Bike. Piloted to glory by the likes of Jonas Vingegaard, Wout Van Aert, Christophe Laporte and Marianne Vos, the S5 has won Classics, Monuments, Green Jerseys, two Tours de France and, most recently, the 2025 Vuelta a España. So, when a new model launches, the world is watching.

Overview

There’s always an element of risk in changing something that’s already extremely good. But Cervélo clearly understand their market. The 2026 model S5 has undergone a series of strategic aerodynamic changes to take full advantage of the latest UCI regulations governing tube depths. To the surprise of no one, the new model is ‘lighter and faster’. To be more specific, Cervélo says the 2026 iteration of the S5 is the fastest aero bike in the pro peloton – 6.3 watts faster and 124 grams lighter than its predecessor, which was also claimed to be the fastest aero bike in the pro peloton when it first arrived. In the review configuration supplied by Cervélo, the S5 weighed in at an impressive 7.34 kg without cages or pedals.

Styling

Same but different is how I’d describe the styling. This is far from a major aesthetic overhaul – in fact, at first glance the new S5 shares plenty of similarities with its predecessor – however closer inspection does reveal some key differences, mostly at the front-end which has been redesigned in pursuit of even greater watts and speed. Both the fork and head tube are slimmer but also deeper with sharper trailing edges. The much talked about V-stem cockpit has also been reworked into a one-piece system, removing the need for the split stem section to be bolted to the top bar. The stem arms themselves rise at a significant angle (not unlike the Bianchi OLTRE, which I reviewed in 2024), while a wider opening and smoother transition between the stem and handlebars help to further reduce turbulence and drag. Curiously, despite all the aerodynamic optimisation, around 5cm of the front brake hose is still exposed on the inside surface of the fork arm.

Frame & geometry

When the S5 frame was last updated, it saw the introduction of a significantly deeper headtube, and Cervélo has gone even further with the 2026 model. While the overall silhouette is familiar, the forks are deeper and sharper, while the head tube depth is enormous – almost on par with the freakish Ridley Noah. At the back, the seat stays have also been dropped a little. However, despite all this, the overall S5 geometry remains largely the same as the previous model, with just a 2mm increase in bottom bracket drop (now 72mm) and slightly larger fork offset.

Cervélo’s updated HB19 one-piece cockpit features a modestly flared design 4cm wider in the drops (2cm on each side) to offer a more aero body position on the hoods and greater stability when descending and sprinting. The bars come in nine widths, and Cervélo says all sizes are UCI-legal despite the recent regulation changes. Unlike its two-piece predecessor, this cockpit can’t be adjusted (other than spacers to move it up and down), so it’s best to take the time at your LBS to ensure you have the right fit. On the topic of sizing, Cervélo also gives purchasers 60 days to make sure their chosen bar option is correct – if it isn’t, you can swap it over for a different size set-up at no additional charge. If you own the previous S5 model, the cockpit mounting system remains unchanged, so the new one-piece handlebar is also reverse compatible.

Moving to the other end of the bike, the new SP34 Carbon seatpost has been slimmed down to help reduce drag with two options available – 15mm and zero setback – while the seat tube cut-out has been specifically optimised for pairing with the new Reserve 57|64 aero wheelset.

For riders who like to do their own maintenance, I’m also reliably assured the new S5 is considerably simpler to maintain than its predecessor, particularly at the front end, thanks to easier access points for the bars and headset.

Components

Disc-brake only, the 2026 model S5 is available in five standard specifications, all of which feature dual-sided power meters – 4iiii Precision Pro for Shimano, Quarq for SRAM. The most intriguing is the single chainring option equipped with a SRAM Red XPLR AXS 1×13 groupset. The review build was kitted out with the sublime SRAM Red AXS E1 12-speed groupset and completed with a Selle Italia NOVUS BOOST EVO SuperFlow carbon saddle. A variety of Cervélo front and rear accessory mounts are included, while the SRAM Red AXS review build also arrives with the latest Hammerhead Karoo touchscreen head unit.

Wheelset

Away from the frame itself, the S5 features Reserve’s all-new 57|64 Turbulent Aero wheelset – developed specifically for pairing with the 2026 S5 frame and seat post. Reserve says the new design ensures air flows smoothly over the entire frame, making the wheels more efficient and incredibly stable in crosswinds. With 57mm up front and 64mm at the rear, the rims are slightly deeper than the outgoing S5 model and have been optimised for use with 29mm tyres. Tubeless-ready and with 25.4mm front internal width and 24.4mm at the rear, the hooked rims are impressively wide and laced around superbly smooth DT Swiss 180 ceramic bearing hubs, which never disappoint. Ultegra and Force-level builds come with DT Swiss 240 hubs. As mentioned earlier, Cervélo claims the new S5 and Reserve 57|64 wheelset is 6.3 watts faster than the previous S5 at 50km/h, with consistent benefits seen across a +/- 15-degree yaw angle range. Of course, no deep-section rim is truly immune to the effects of crosswinds. On the longest ride of this review (~80km to La Perouse in Sydney), I experienced extremely blustery conditions with frequent bursts over 40kmh – the wheels performed admirably in all but the very strongest of gusts. It was quite impressive for rims of this depth.

The ride

To the surprise of no one reading this review, the S5 is indeed a very fast road bike – blisteringly so, in fact. Light, agile and with exciting acceleration, it’s aero-optimised in almost every way imaginable, configured to convert every available watt of power into on-road speed – something even a mere mortal club cyclist like myself could easily discern. Entirely reflecting its race pedigree, the S5 places you in a compact and reasonably aggressive riding position. There’s an unmistakable feeling of efficiency as you tap along and, to semi-paraphrase Greg Lemond, the S5 simply makes going faster easier. Perhaps most tellingly, I found my cruising speed was consistently around 2-3km/h faster on roads I ride all the time – without even trying.

As expected, the ride feel is definitely on the firmer side with very responsive and direct steering. In a straight line, it’s an absolute bullet, but it did take a few rides to understand its handling quirks and gain the confidence to really throw it into high-speed corners – after which it was a whole lot of fun. Running tubeless at around 60psi with the generously wide Reserve 57|64 rims, it really is quite a comfortable ride too, which maybe you wouldn’t expect with a bike like this – so that’s a big tick. Like most aero builds, the faster you go, the better it gets. Having said that, the S5 also performs considerably better at lower speeds than many of the aero bikes I’ve ridden in recent years.

The shifting and braking with SRAM Red AXS is top shelf. Acceleration is excellent, especially when you’re already moving at speed. Climbing is also way above average for an aero-oriented bike, making it considerably more versatile than many of its peers. Downhill performance is sublimely good, as is scooting along while hiding in the wheels in bunches. The whole experience is incredibly efficient, and the S5 just rolls and rolls and rolls. On multiple occasions during the review, I actually had to brake for the riders in front because I kept rolling up to their wheel with no additional effort. Impressive.

The other thing worth mentioning is how the S5 sounds on the road. Entirely unprompted during the review, numerous people mentioned that it sounds absolutely menacing – a low, brooding hum as you tap along, followed by an intimidating ‘whoosh’ as you really begin to stomp on the pedals.

Summing up

The new Cervélo S5 is not a bike. It’s a weapon; a sublime race-optimised aero machine aimed squarely at performance-obsessed riders who want to go as fast as possible by reducing drag and maximising every available watt. Yes, it’s a bona fide crit crusher, but it can more than hold its own when pushed beyond that, as evidenced by its WorldTour pedigree. If that sounds good to you – and your pockets are deep enough – you will love it. Enjoy.

Specifications

RRP:                   $18,500

COLOUR:                       Five Black (gloss finish)

FRAME:                           Cervélo All-Carbon S5

FORK:                Cervélo All-Carbon, Bayonet S5 Fork

HANDLEBAR/STEM:                 Cervélo HB19 Carbon (400×100, 54cm frame)

SADDLE:                         Selle Italia NOVUS BOOST EVO SuperFlow Carbon

SEAT POST:                    Cervélo SP34 Carbon

BRAKES:                         SRAM Paceline X Centerlock

ROTORS:                        SRAM CenterLine XR (160mm front/160mm rear)

SHIFT LEVERS:                           SRAM Red AXS E1

FRONT DERAILLEUR:              SRAM Red AXS E1

REAR DERAILLEUR:                 SRAM Red AXS E1, 12-speed

CASSETTE:                    SRAM Red AXS, 12-speed, 10-33T

CHAIN:                            SRAM Red E1

CRANKSET:                   SRAM Red AXS E1, 50/37T, DUB w/ Quarq power meter

BOTTOM BRACKET:                  SRAM DUB Ceramic, BBright

RIMS:                 Reserve 57|64 Carbon (tubeless compatible)

HUBS:               DT Swiss 180 Dicut