Bespoke Blog

Cervélo has unveiled the new 2019 S5, and it ticks all the usual upgrade boxes; stiffer: check, more aero: check... but the big news is the addition of disc brakes, now standard across the whole S5 range

It's one of the most eagerly anticipated launches, the arrival of the brand new Cervelo S5. This is an important release because it's worth remembering how critical Cervelo has been in the development of aero bikes since the debut of the original Soloist, arguably the first road bike designed with aerodynamics in mind.

The S5 is the company's flagship aero bike, and it's often held up as a benchmark aero bike in competitor wind tunnel tests. There's a lot of change with the new S5 and probably the biggest is that it's now only available with disc brakes.

That's right; the S5 rim brake is no more, the new improved model will be available exclusively with discs - a mark of how much they've become the de facto standard for aero road use.

We could have predicted the new S5 would be designed around disc brakes, just like the new Cannondale SystemSix and Specialized Venge, but we weren't expecting a radical new front-end. Instead of a conventional head tube with a steerer tube inside, the new fork has a steerer tube that effectively sits in front of the fork, sandwiching the short head tube. A bit like a mountain bike triple clamp fork in fact.

Because there's no conventional steerer tube, the head tube is able to be made much narrower which improves the aerodynamic performance. It also makes internal cable routing much easier, which really has been the key thrust of the design of the new S5.

To enable fully internal cable routing for any mechanical or electronic groupset and hydraulic brake hoses, the head tube is hollow and the cables pass through the bearings very smoothly.

Atop this new fork and head tube design are the radical V-shaped stem and new aero handlebar. The stem achieves two objectives; easy internal routing with smooth lines and enhanced airflow along the top tube.

The new S5 is 42 grams faster than its predecessor - that's the equivalent of 5.5 watts

The aero handlebar is also brand new and while the two components look like a one-piece design, they are in fact separate. This ensures bike fit, stack, reach and bar angle, can be fully adjusted to suit each rider.

The rest of the bike has been refined as well. The newly shaped downtube now curves around the front wheel, as does the seat tube around the rear wheel, and there's an aero seatpost with an internal seat clamp.

Frame weight is 975g for a size 56cm which is very competitive not only with leading aero bikes but also with regular road race frames too.

All these changes have netted a considerable aerodynamic improvement. Cervélo claims it has reduced drag by 42g compared to the previous S5 when measured with the rider in a wind tunnel, the equivalent of 5.5 watts.

Other changes have also focused on frame stiffness and geometry. Cervélo has increased the bottom bracket stiffness by a whopping 25% and the head tube is 13% stiffer, both changes which should attribute a much more responsive ride. The geometry is more agressive and mimics the R5, which was updated last year, in possessing a lower bottom bracket, longer reach and lower stack.

Another change we like is the clearance for wider tyres. Up to 28mm tyres will fit, so if you aren't racing you could consider fitting wider tyres. More air volume equals more comfort, and together with their carbon expertise, we're expecting this to be a particularly comfy aero road bike (in relative terms).

13% increase in headtube (torsional) stiffness over the previous S5, and a 25% increase in bottom bracket stiffness over the previous model

The new S5 will be available in a range of builds, including Ultegra and Dura-Ace Di2 and SRAM RED eTap, and as a frameset.

Want to deep dive into the tech side of the S5? Unsurprisingly Cervélo has that covered, with a detailed Tech Paper available for download. Get the PDF here.

We can't wait to get our hands on one of these for a ride, and we'll be taking a closer look at the S5 here on the Bespoke blog. Look out for more details coming soon.