Cervelo says new S5 is “at least 5 watts faster than the bikes of our competitors”

Cervelo has officially launched the updated S5 road bike that Visma-Lease a Bike is riding in the Tour de France, saying that it’s confident the new bike is “at least 5 watts faster than the bikes of our competitors”. At what speed? We’ve asked but haven’t received an answer yet, although Cervelo usually bases its aero claims on 48km/h (30mph) wind speeds.

“These gains are realised primarily at the front end of the bike, but the integration of the asymmetric profiles of the seat tube and rear wheel are a significant source as well,” says Cervelo.

In a nutshell, Cervelo says that it has improved the S5’s aero performance, reduced the overall weight by 124g, and maintained stiffness, while integrating new Reserve 57|64 Turbulent Aero wheels.

The new S5 – which you’ve probably already seen because Visma-Lease a Bike riders have been racing on it for a while (above) – comes with an updated cockpit, tweaked handling (although the fit geometry remains the same as previously), and a redesigned front brake mount.

Cervelo claims that the new S5 (frame, fork, handlebar, seatpost, wheels) is 6.3 watts more efficient than the outgoing model across a -15° to +15° yaw sweep (as mentioned, Cervelo hasn’t given us a speed at which that applies). According to Cervelo’s testing, the new S5 is 10.7 watts more efficient than the Cannondale SuperSix, and 15.7 watts more efficient than the Specialized SL8 (in other words, it would take less power to hold the same speed on the new S5, it says).

A new handlebar/stem

The one-piece HB19 handlebar/stem is a new design, Cervelo previously using a separate V-shaped ST35 stem and HB14 handlebar. The V-ness isn’t new, but the one-piece construction is.

Cervelo says that the drops and tops have been reduced by 3.8mm and 2mm, respectively, compared with the HB14.

The drop sections flare outwards meaning that the hoods are considerably narrower than the ends of the bar.

You get a 40 x 100 H19 fitted as standard to an S5 in sizes 54cm and 56cm, for example. This one measures 40cm at the hoods and 44cm at the ends of the bars (measured centre to centre). As with other flared bars, the idea is that you can get a narrow aero position with your hands on the hoods, with extra stability and leverage when you’re down in the drops.

Cervelo is keen to point out that all HB19 sizes are UCI-legal, even with the most recent regulations change.

> UCI issues “further clarification” on new tech rules, including controversial 40cm handlebar width… 

Cutting weight

It won’t surprise you one bit to hear that Cervelo claims weight savings with the new S5. ’Twas ever thus.

Making the head tube and fork airfoil profiles deeper than previously actually moves things in the opposite direction – the new fork is 53g heavier than the previous version – but savings from the frame, seatpost, and bar/stem more than compensate, taking the overall weight down by 124g, according to Cervelo’s figures.

“While the increase in fork and head tube depth added weight, we optimised the layup and hardware to make the system lighter,” says Cervelo.

If you want the nitty-gritty, here are the various claimed weights:

Frame 1,006g
Fork 465g
Handlebar/stem 337g
Seatpost and hardware 205g
Cockpit hardware 19.3g
Overall system weight 2,032.3g

Geometry tweaks

Cervelo has made a few small changes to the geometry, although fit measurements remain the same as before.

The bottom bracket has been lowered, but only by 2mm to take into account the use of larger tyres, which now rule the world. The geometry is optimised for 29mm tyres, whereas the outgoing S5 was designed around 26mm tyres. The lowered BB also allows for the fact that crank lengths have been shortening over recent years.

The fork offset has been adjusted slightly to maintain trail (the distance that the centre of the front tyre’s contact patch trails behind the point where the bike’s steering axis intersects with the ground) with the larger tyres that are commonly being raced these days.

> How to read a bike geometry table: the numbers made easy 

New Reserve 57|64 Turbulent Aero wheels

The updated S5 comes with new 57|64 Turbulent Aero wheels from Reserve, which we’ve also seen used by Visma-Lease a Bike over recent weeks. Cervelo and Reserve are both owned by the same parent company and co-developed the new wheels specifically for use in the S5 frame.

The aim here was to maintain the weight of Reserve’s existing 52|63 Turbulent Aero wheelset while adding depth to improve the aero performance

“The offset of the wheels perfectly matches the asymmetry of the S5 seat tube, and they tuck right into the wheel cutouts,” says Cervelo. “This ensures that air flows smoothly over the entire bike, and Reserve’s Turbulent Aero approach makes them incredibly stable, even in crosswinds.”

New Cervelo S5 range

The S5 is a top-level aero road bike raced by Jonas Vingegaard, Wout van Aert, Simon Yates, and the rest of the Visma–Lease a Bike team. Bikes at this level never come cheap. Here’s the range:

Cervelo S5 Red XPLR AXS 1 £12,000
Groupset SRAM Red 1 AXS (with power meter)
Wheels Reserve 57|64 Turbulent Aero, DT Swiss 180 DICUT hubs

Cervelo S5 Red AXS £12,500
Groupset SRAM Red AXS (with power meter)
Wheels Reserve 57|64 Turbulent Aero, DT Swiss 180 DICUT hubs

Cervelo S5 Dura-Ace Di2 £12,000
Groupset Shimano Dura-Ace Di2 (with 4iiii Precision 3+ Pro power meter)
Wheels Reserve 57|64 Turbulent Aero, DT Swiss 180 DICUT hubs

Cervelo S5 Force AXS £9,200
Groupset SRAM Force AXS (with power meter)
Wheels Reserve 57|64 Turbulent Aero, DT Swiss 240 hubs

Cervelo S5 Ultegra Di2 £9,200
Groupset Shimano Ultegra Di2 (with 4iiii Precision 3+ Pro power meter)
Wheels Reserve 57|64 Turbulent Aero, DT Swiss 240 hubs

All of these models come with 29mm Vittoria Corsa Pro TLR G2.0 tyres.

The Cervelo S5 is also available as a frameset (frame, fork, HB19 cockpit, headset, SP34 carbon seatpost, thru axles) for £5,400.

www.cervelo.com