Bike at Bedtime: take a look at the Cervelo S5

Team Jumbo-Visma riders have switched from Bianchi to Cervelo this year, spending most of their time on the lightweight R5 or on this aero S5.

The S5 is a direct descendant of the Soloist, the brand’s pioneering aero road bike that it released back in 2002. Of course, lots has changed since then although the focus is still on efficiency.

The latest S5 was introduced in the 2019 model year and Cervelo claimed an aero saving of 5.5 watts (42g of drag) over the 2014 version at 40km/h.

“The most noticeable visual and performance change comes at the front of the bike,” said Cervelo. “An entirely re-conceptualised aero cockpit achieves significant improvements in aero performance. Fully internal cable routes are provided for both electrical and mechanical shifting while maintaining ease of adjustments. Slip-in spacers can be used to adjust stem height and bar tilt without detaching any cables, making adjustment far simpler than in a typical aero bike. 

“Importantly, the V-shaped stem made it possible to fully hide mechanical shifting cables. The stem was specifically designed to minimise the angle of cable bends, so riders get both perfect shifting/braking and the full aero benefit of hidden cables.”

As well as hiding the cables, the V-shaped geometry of the stem is designed “to present less obstruction to the oncoming high-velocity airflow between the rider’s arms”. The idea is that this high-velocity flow of air is maintained along the top tube, through the thighs of the rider, and past the seat post. 

“When compared with a standard stem system, the increase in flow velocity past the seat post results in a smaller low-pressure wake region behind the thighs and reduces drag,” according to Cervelo.

This barely touches the surface of the aero development work behind the latest version of the S5. If you want to know more, check out the white paper that Cervelo produced to accompany the launch. 

The S5 isn’t just about aerodynamics, though. Cervelo also says that it was able to increase head tube stiffness by 13% with the latest model in order to improve handling, and to increase bottom bracket stiffness by 25%. Where would the road race bike market be these days without a few statistics thrown into the mix? 

Cervelo also dropped the bottom bracket to lower the rider’s centre of gravity, the idea being to provide greater stability when turning and riding at speed, and increased 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) to increase stability further. 

Bike geometry 101: Learn why frame angles & trail matter

Did all that work pay off? In short, yes, it did. When we reviewed the third generation Cervelo S5 we called it “one of the most exciting bikes in the peloton right now and a mighty impressive piece of engineering”. 

We found it super-fast and more comfortable than you might expect for a bike of this kind. With a frame weight of 975g (56cm model), it’s pretty light for an aero road bike too, although it’s eclipsed in this respect by bikes like Specialized’s Tarmac SL7 that have come along more recently. 

The Cervelo S5 is now a disc brake-only model with complete bike prices starting at £5,699.

www.cervelo.com