Thanks to a new cockpit, the Cervélo S5 is simpler but faster.
Words Charlotte Head
All bikes have a definite life cycle, but once the latest model is released, its engineers don’t ever just sit back and relax. ‘When you’re developing big new ideas, you have to pick an endpoint and launch a product,’ says Maria Benson, Cervélo’s director of product management. ‘But in reality we don’t stop looking at how it can be improved after the bike is launched.’
Immediately after the last S5 was released in 2018, work started on its successor, which has now arrived to sit at the top of Cervélo’s road racing line-up, and it has already seen some action. While the men’s Jumbo-Visma team were racking up wins on the previous S5, this latest model was being raced by the women’s and development teams in early 2022.
The biggest changes include deeper tube profiles, thanks to a relaxing of UCI rules, and subsequent remodelling of sister company Reserve’s wheels so that the components continue to work aerodynamically as a whole. The distinctive V-shaped cockpit and external steerer remain, although both have been redesigned to make them more service and adjustment-friendly.
‘We thought, hey, this is pretty good. Let’s refine this and distil it down into a package that’s easier for the team mechanics, easier for the consumer and easier for the bike shop,’ says Cervélo’s engineering manager, Scott Roy.
Step by step
‘The concept of the V stem style came from the idea that hiding the cables was one way to smooth out the airflow around the cockpit, without affecting the performance of cable shifting,’ says Benson. ‘The level of aerodynamic advantage was actually a secondary discovery.’
The first model may have been aerodynamic, but it was also complex. The team initially struggled to create a design with a one-piece fork that worked well with the frame, settling for a two-piece system with an alloy topper and a variety of pre-load bolt lengths to accommodate different stack heights. Over time, and as the bike excelled in the pro ranks, Cervélo saw the system was inherently stronger than expected and didn’t need as many fail-safes.
‘That’s when the refinement happened. The fork is now one piece, which saves a ton of weight, and the big alloy topper is no longer there,’ says Roy. The unit is also stiffer since it’s one piece, says Cervélo, and this new design shifts 53g.
Another change to the cockpit is the removal of the stepped handlebar angle adjustment. The new S5 allows infinite adjustment between 0° and 5°, with the aim of offering more precise individual fits.
A new rulebook
A change to the UCI rules removed the distinctions between road and time-trial bikes, which was a big win for road aerodynamics. For the S5, this has meant deeper tube profiles and a claimed total saving of 8.3 watts at 48kmh.
One casualty of these changes is Campagnolo. The frame no longer accommodates anything other than brake hoses from the shifters. Campagnolo is the only main groupset manufacturer not using wireless shifters, so the S5 is now only compatible with Shimano Di2 and Sram AXS groupsets.
The frame isn’t the only place where the new S5 has seen aerodynamic changes. The team developed the 52/63 wheelset using turbulent as well as the standard laminar flow testing, and Cervélo claims the new wheels are 7 watts and 6.6 watts more efficient at 48kmh in respective tests. The shallower, wider front rim is designed to provide better handling in windy conditions, while the deeper, narrower rear rim chiefly concerns itself with reducing aerodynamic drag.
It’s not just aero designs that make a bike quick, though, and Cervélo has recognised this.
‘We’ve really found that a wider tyre paired to a wider rim – internally and externally – is quite fast,’ says Benson. ‘It also allows you to run lower pressures and add more comfort to the overall ride. When you’re talking about a really stiff, aerodynamic bike, that is quite important.’
Accordingly, the new S5 has tyre clearance for up to 34mm, compared to 28mm previously. While we don’t think we’ll be seeing Wout van Aert rocking 34mm tyres at the Tour de France any time soon, the changes should help to make the S5 as appealing to everyday riders as it is to the pros.
Cervélo S5, Shimano Dura-Ace Di2 or Sram Red AXS – $17,500
Cervélo S5, Shimano Ultegra Di2 or Sram Force AXS – $12,500
Cervélo S5, frameset only – $7,600