We take a closer look at the new Cervélo S5 and give our first ride review
Cervelo S5: What’s new?
In 2014, when the Cervélo S5 went to market it was probably already outdated. As damning as that indictment might sound, it’s because it was designed around rim brakes and 23mm tyres and following couple of years saw radical changes to road bike technology: none more recognisable than current trend for wide tyres and disc brakes.
So, with this in mind the new Cervélo S5 is another in a long run of new aero bikes that is disc brake specific. It’s much the same story as the other brand’s: removing the rim brake calliper gave more room on the frame to innovate on the front end of their bike. Then there’s the fact that disc brakes mean room to accommodate wider tyres and the new Cervélo S5 will happily gobble up 28mm tyres.
New Cervelo S5: The V-shaped stem
Aero bikes are no strangers to funky shapes and ‘out there’ designs, so while the new v-shaped stem might be visually arresting, it doesn’t feel out of place. According to Cervélo, it’s the result of many hours aero testing and it has found the design to be the fastest through the air compared to a standard stem.
Cervélo found that the v-shaped hole allowed the air to flow cleanly between the arms of the stem rather than being disrupted like when it has to pass around a standard stem. Research showed that the air was quicker to re-attach to the top tube when it wasn’t disrupted, equalling less drag. According to Cervélo it was also significantly smoother around the legs of the rider.
But the design isn’t purely aerodynamic, another significant concern of the Canadian brand was cable routing. The new bike’s cables are routed completely internally, and a key consideration – especially for the UK market – was hiding away the mechanical cables completely. The new v-shape allows a much more fluid cable routing that avoids kinks at any point.
While the stem might look like it has a dramatic rise in reality, when slammed, it is in fact the same height as an old Cervélo S5 with a slammed -6 degree stem. Do not be fooled, this is an aggressive bike.
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It is possible to change the height of the bars using 5mm spacers with two-piece designs. 2.5mm spacers are also used where the bar interfaces with the stem and you adjust the height of the bars even further. A final level of adjustment is possible by tilting the angle of the bars and this is something we’ve seen lots of the new aero bikes released this summer featur in varying forms.
Through its work with Mark Cavendish, Cervélo knew the new iteration S5 had to be stiffer, especially at the front end. To do this, the fork steerer was removed and replaced by a tensioning rod and the front portion of the head tube has been built up for additional stiffness.
To be specific, Cervélo claims that the bottom bracket of the new S5 is 25% stiffer than the last bike whilst the head tube is 13% stiffer.
If the new stem is too wacky for you, or you need a length longer than 130mm, then fear not, there will be a conversion kit available it can run with a standard stem.
New Cervelo S5: How much more aero can bikes get?
Not much, that’s the reply of Cervélo’s leading engineers who say that aero road bikes are getting close to the peak of current, UCI legal aerodynamics.
As we’ve seen, a great deal of the aerodynamic leg work has been done at the front end of the new S5, but that doesn’t mean Cervélo shied away from the rest of the frame, it’s just less visually pronounced. Changes have been made on the rear, including a newly designed seat post and newly shaped seat stays, including where they meet the seat tube.
The overall result is a claimed 42g of drag saved over the previous S5 when wind tunnel tested with a rider – that’s 5.5watts.
So, if the bike can’t get that much faster, then the focus now has to shift to make the system more effective. What that means is that aero bikes can become more comfortable and well rounded, whether that’s by the addition of disc brakes, wider tyres or geometry changes, talking of which…
New Cervelo S5: Geometry changes
Starting with the C-series and then more latterly with the R-Series, Cervelo has been placing a lot of emphasis on the handling and ride quality of its bikes.
What the brand names ‘the psychology of the ride’ translates more broadly as how comfortable you feel on the bike and, to a greater extent, how confident it makes you feel when you ride. Ultimately, the aim was to keep an elite level feel but inspire confidence in whoever was riding the bike.
To do this, Cervélo tweaked the handling geometry of the bike by lengthening the bike’s trail to add more stability and dropping the bottom bracket height. It’s the same tweaks that were made on the Cervélo R5 and the result is much the same: incredible handling.
Cervélo has not changed the fit of the Cervélo S5, and the stack and reach remain the same as the last bike.
First ride of the new Cervelo S5
Having spent a long time riding the Cervélo R5 (it’s one of my favourite bikes) it’s clear that it has a shared DNA with the new Cervélo S5. The handling of the S5 mirrors the razor sharp handling of the R5, making it one of the best descending aero bikes I’ve ridden (along with the Specialized S-Works Venge).
The dropped bottom bracket had the exact same affect, making it feel like you’re sitting in the bike rather than on top of it. It’s easy to flip it over in corners and lean into them. The extended trail makes the bike hold its line no matter the corner, never wavering from where you point it.
It’s worth repeating: don’t be fooled by the rise on the stem, the Cervélo S5 is an aggressive bike, and riding with the bars slammed on my test bike I could feel it in my back after the 90 or so kilometres we rode around Girona. It’s not that it’s uncomfortable, it’s just aggressive, and the ride is actually very compliant; no doubt helped by the slightly wider tyres. After all, if you find the bike too aggressive there’s always the Cervélo S3 you can ride which has 16mm more stack.
The final sticking point for any modern aero bike has to be: how easy it is to live with? If anything, this summer and it’s multitude of aero bike releases has shown how there’s been a step away from pushing to be the most aerodynamic, with brands now recognising how important it is to be able to live with and ride the bike everyday.
Only time will tell for the new Cervélo S5, so be sure to check back for the long-term review in the future.
New Cervelo S5: Prices and specs
Cervélo S5 Disc Dura Ace Di2 £9,699
Cervélo S5 Disc Red eTap £9,299
Cervélo S5 Disc Ultegra Di2 £6,999
Cervélo S5 Disc Ultegra £4,899
As soon as we have word of the UK pricing we’ll be sure to update this page.