Cervelo S5 Disc first-ride review: Even faster, more refined

by Dave Everett


We’re now much closer to the end of the cycling season than the start, and for obvious reasons, most brands choose to launch their new bikes earlier in the year. The Tour de France was a cram-fest of new aero bikes from Cannondale, Specialized and Trek. So, for a brand to launch this late in the year suggests that it might be special enough to almost sell itself.

Is the new Cervelo S5 a bike that shines, and a bike that will see the newly partnered Sunweb team whip along with ease in 2019? CyclingTips sent roving reporter Dave Everett to Cervelo’s launch event in Girona, Spain, to find out.


It’s all about the V

The one standout design element that I’m sure is going to have cyclists arguing in cafes across the globe will be the new bar and stem setup. Developed with 3T, it’s similar in some ways to the Aduro integrated aero bar that Cervelo introduced on the P5 time trial bike in 2012. The new bar and stem may not quite rival the buzz we saw around the double-decker Hover bar that Canyon debuted on the Grail gravel bike, but I’m sure it’ll still divide opinions.

The bar and stem look fully integrated from a distance, but are actually two separate components so there’s still almost as much adjustability as usual. Cervelo has an out-front computer mount prepared, too.

The proprietary design accomplishes two jobs at once. Firstly, the cable routing for both mechanical and electronic drivetrains is now fully internal, and the split stem avoids tight angles for both shifting and braking. Secondly, the design is claimed to tidy the air behind the stem and around the rider. According to Cervelo, the new bar – along with a plethora of other aero upgrades that I’ll discuss in a bit – has shaved off 42g of drag (when measured along with the rider) over the current S5 that this new one is replacing.

“The entry into it [this bike] was the desire to bury the cables,” explained Cervelo product manager Phillip Spearman. “It seems a bit weird, but a lot of the time, people design a bike [first] then try and bury the cables. It turns out that concealing cables is remarkably complex for something that seems so simple. This bar is actually the function of first and foremost burying the cables.

“Cervelo wanted smooth cable lines. We have a history of only turning the cable on a single plane once it enters the bike. The goal as always was to have the cables passing through the middle of the bearing, so then you don’t have it swinging backwards and forth.”

Despite the integrated nature of the new bar and stem, there’s still the usual range of customisation. The stem height can be adjusted in 5mm increments with headset spacers, up to 30mm. The bars themselves can also be raised an additional 2.5mm, and the rotation set at 0°, 2.5°, or 5° angles through a series of shims. And since the bar and stem are separate components, length and width can be picked at will. The bars come in widths from 38cm through 44cm, and stems in length from 90mm to 130mm.

It is possible to fit a standard stem, too, although this would obviously cancel out much of the aero gains that the proprietary bar-and-stem combo offer. And to be brutally honest, it would look pretty ugly, too, but hey, that’s just a personal view.

Cervelo is also looking at the possibility of developing clip-on aero bars, and if everything goes as planned, it’ll be a very clean setup. The plan is to use the same mounting holes as the bar and stem, so the result should be very tidy.

A stiffer and lighter frame, updated geometry, and a slick new fork

That bar and stem may be the visual highlight of the new Cervelo S5, but what it’s attached to deserves attention as well.

Instead of a conventional fork with an internal steerer tube, the new S5 fork sandwiches the head tube at the top and bottom; there’s nothing but a threaded rod inside the head tube to preload the headset bearings. It’s just as slick-looking and unconventional as the bars, but it too is designed that way for a reason. With no steerer tube inside, the head tube (and the fork itself) can be made narrower and more aerodynamic, and the pseudo-dual crown layout is stiffer, too.

“The external fork design is really there to support the [internal routing] system,” said Spearman. “There is no steerer tube inside, just a tensioning rod, which means it’s hollow. This allows the cables to pass down smoothly, by passing through the bearings. ”

Behind the head tube, the rest of the new S5 frame is visually evolved from the current model, but there’s a lot of change below the surface. Although tube shapes are basically carried over, for example, revisions in the carbon fibre lay-up make the latest version lighter than before. Claimed weight for a painted 56cm frame is just 975g, but claimed stiffness is up 25% at the bottom bracket, and 13% at the head tube.

There are even bigger changes in the geometry, which has been pulled over from last year’s R5. Stack and reach figures are carried over for a more predictable progression through the size range, and the handling has been toned down for more stability. The bottom bracket is closer to the ground for a lower centre of gravity, and all sizes get a longer (and consistent) trail dimension that both slows down the steering and reduces toe overlap.

“When we talk about improving the ride quality, it’s imperative to us that we pay attention to all sizes, and not only those sizes in the middle range,” said Spearman. “As such, we followed the precedent we set with R-Series, and we standardised the trail across all sizes. What this means, is that the smaller-sized riders are no longer asked to fight the instability issues associated with having too much – or mismatched – trail, and are riding a bike that handles the same as the benchmark 56cm.”

And what about the brakes? Sorry, rim-brake fans, but you’re out of luck. The new S5 is disc-only with 160mm-diameter rotors standard on complete builds; 140mm ones will also work for lighter riders.

Going along with the new flat-mount disc calipers are 12mm thru-axles at both ends. These use Cervelo’s version of the RAT (Rapid Axle Technology) design that corporate partner Focus introduced a few years ago, but with an additional safety feature to prevent unintended opening in mass-start road racing situations. For those wanting more traditional thru-axle systems, there will also be a threaded axle with a flush, tooled head available aftermarket.

Pricing and build options

Cervelo will offer the new S5 in four complete builds, plus a frame-only option. Graphics are definitely on the more subtle side throughout — the higher-end build has an especially stealthy black/white/graphite scheme while the lower-end builds have a bit more colour. Retail prices are as follows:

Shimano Dura-Ace Di2: US$11,500 / AU$14,500 / €10,999 / £9,699
SRAM RED eTAP: US$11,500 / AU$14,000 / €10,499/ £9,299
Shimano Ultegra Di2: US$8,500 /AU$10,500 / €7,999 / £6,999
Shimano Ultegra mechanical: US$6,000 / AU$8,000 / €5,499 / £4,899
Frameset: $5,200 / AU$6,500 / €4,699 / £4,299

The new Cervelo S3: An aero bike for the masses

Also getting a revamp is the workhorse S3 aero road bike model, which, unlike the S5, will eventually be offered in both rim-brake and disc-brake form (just the disc-brake version will be offered initially). Like the S5, the frame shape is mostly evolutionary relative to the current S3. Frame weight for a 56cm size is claimed at a respectable 1,100g.

The new S3 has had a whole lot of engineering work thrown at it for 2019.

Up front is a more standard fork, and the matching stem and bars are a lot more conventional than the outlandish S5 cockpit. A fresh-looking forged alloy stem is paired with a mildly aero flat top bar, and combined with the new C-shaped steerer tube, the S3 allows for fully internal cable routing. I didn’t get to ride the new S3, but it seems like the more rounded handlebar shape will please more people than the huge flat platform the S5 bar offers up.

Either way, the S3 is quite clearly a bike the engineers are proud of, especially given the 102g of drag that the new bike supposedly saves over the old one. Most of this, we were told, is a result of the updated internal routing.

Retail prices for the new S3 are as follows:

Shimano Ultegra Di2 disc: US$6,500 / AU$8,500 / €6,399/ £5,459
Shimano Ultegra mechanical disc: US$5,000 / AU$6,300 / €4,499 / £4,159
Shimano Ultegra Di2 rim: US$5,999 / AU$6,000 / £4,999
Shimano Ultegra mechanical rim: US$4,000 / €3,999 / £3,699
Frameset (rim or disc): US$4,000 / AU$3,500 / £2,999

S5 first ride impressions:

I’ll just preface this by stating that, bar a few design choices, I struggled to find much I disliked about the S5. So get set for what could be a taken as a bit of a flowery review. It perhaps also helped that Cervelo chose to debut the S5 in Girona, Spain. With a wide variety of terrain, minimal traffic, and perfect tarmac, it was admittedly the perfect setting for an aero bike launch.

It’s nice to see a frame that seems unfussy in its design language. Some of the more recent aero bikes seem to have more angles than a math class full of kids with protractors.

The S5 I rode was built with a Shimano Dura-Ace Di2 groupset and rolled on Enve’s SES 5.6 Disc carbon aero wheels, neither of which require a major review. As you’d expect, both performed flawlessly. But then again, at US$11,500 / €10,999 for that build option, it should be nothing but top-tier performance.

On the first day of testing, we easily knocked out an undulating 50km in just over 90 minutes, which I feel is more a testament to the bike rather than my current (lack of) fitness. Initial impressions were that, yes, this is indeed a fast bike. But unlike a few other aero bikes I’ve had the chance to play on lately, the S5 doesn’t scream its potential. Instead, the S5 Disc felt surprisingly balanced, going about its intended purpose without the usual aggressiveness that many aero bikes seem to have.

The tight rear end doesn’t make for an overly twitchy bike.

At speeds above 35km/h, the bike absolutely sings, holding its speed with ease. We rode in small groups of about 12 people for the launch, and there’s usually a bit of sketchy and nervous behaviour at these things: new bikes, new people, varying levels of ego, unfamiliar roads. Speeds often fluctuate a fair bit, and the group can turn quickly into a mini accordion of riders trying (but failing) to keep a steady pace. Whether I was lucky enough to get in a good group of bike handlers is up for discussion, but it seemed that everyone, including myself, was quickly comfortable and confident on the S5. A swift pace was set and wheels were kept confidently close together. Everyone just settled in.

While I quickly adjusted to the bike, I didn’t get along as well with the bars. The top of the bars felt slightly too big to grip, especially when wrapped, and the reach seemed too short. Lastly, the stock zero-degree bar tilt felt too low. I’m sure that tilting them with the available shims to either the +2.5° or +5° setting would quickly eliminate this problem, as might raising the hoods slightly.

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Even with all the talk from the engineers about improving comfort before riding, I expected an overly stiff cockpit. The look of it alone seems like it’s built to favour the sprinters, and I expected it to knock the stuffing out of lighter riders like me. But, thankfully, the cockpit is stiff, but not excessively so, nor is it wooden-feeling like some other aero bars I’ve had the chance to use. Sure, it’s not an “all-day comfort” bar, but it manages to find a balance, much like the rest of the bike.

Bar shape is a personal thing, but these broad tops won’t be for everyone, especially those with smaller hands.

Comfort isn’t generally a focal point for an aero bike but, again, Cervelo has done a sterling job at creating a platform that doesn’t beat you up when out for a long ride. It’s not plush or on the same level as a top-tier all-around road bike, but it holds its own against many bikes that claim to be built for longer days in the saddle. It never left me feeling jarred when hitting rougher roads.

The same goes for climbing, and although we only tackled a few 1-2km rises, the S5 handled them in a manner that didn’t scream it was an aero bike. Instead, climbing felt natural, especially when out of the saddle.

Handling felt predictable and intuitive, and was put to the ultimate test when a small dog darted out while I was at the front of the group during the first day’s ride. It was a hairy moment that allowed the nimble – but not twitchy – steering and braking performance to shine. It’s something I was especially grateful for as I hear drinking tapas through a Spanish hospital straw isn’t the easiest of things.

Snappy sprinting is something that a bike like this should be able to handle without hassle, and the S5 definitely ticks this off the to-do list. I’ve found on many aero bikes that when putting the hammer down, there’s often an angry fight to keep the bike planted shortly after that initial kick. Instead, the S5 returned the effort with a smooth snap of speed. You’re never wrestling it to keep on top of the power.

It’s obvious to say that aero bikes should feel fast under you, but yet the latest incarnation of the S5 feels not just slippery, but it has a level of slickness that seems manageable and stable.

I really enjoyed this bike, and although I have a few complaints about the bar, and can’t comment on the ease of maintenance, the new S5 seems to be a bike that has come of age. It’s a matured ride, showcasing not just what Cervelo has recently developed, but also the knowledge garnered from those early Soloist days to the present day.

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