Cervelo S3 Disc

Cervelo S3 Disc

Cervelo’s S3 has been a long-standing member of the company’s range.

A hybrid between the Classics oriented R3 and the aggressively aero S5, making a bike they claim is built to “pull away from the peloton or put the hurt on a Saturday morning group ride”. Now married to disc brakes and claiming to be faster than ever, I was keen to put these claims to the test.


The heart of any good road bike is the frame, and this is where Cervelo put the work in. The S3d takes an aerodynamic front triangle modelled on that of the S5 and binds that to the thinner stays of the R3 on the rear for improved compliance. Cervelo claim the disc model of the S3 is 9 % stiffer and 2 watts faster on aerodynamics than the rim brake version (still available if that’s your thing) and on inspection I’m inclined to believe them. The bottom bracket has enough carbon to break the Paris agreement, internal cable routing for both Traditional and Di2 drivetrains and even the bottle mounts have been placed to best optimise their aero capabilities. The S5 still reigns supreme as the flagship aero machine in Cervelo’s range with flattened stays and a few other subtle tweaks, but the two bikes are closer than you might think.


Through axles on the front and rear keep things stiff in the corners without any real change in weight. Some riders may also find them easier to use, so a double win there. The one trade for this technology is when it comes to those who have an investment fund’s worth of different wheels waiting to be used. Given that the bike uses disc brakes and that moving to these instead of callipers will require new wheels for most riders anyway, this isn’t as much of an issue as it sounds. For the increased stiffness and ease of use, this tester thinks it’s worth it for most riders.

The build tested is what I’d describe as “workhorse”. A mechanical Ultegra 11spd group-set with an FSA SLK Mid Compact crank-set takes care of drivetrain duties. Di2 is available in the build kit above the one tested if that is your preference as well. An 11x28 spread is a conservative choice, offering more range than narrower options without massive jumps to help maintain a smooth cadence. Shimano also take care of braking duties with the RS805 hydraulics matched up to a 140mm rotor. For those of you yet to try disc brakes the power and modulation on offer may come as a surprise. Reliability is a bonus of this system (our muddy legged cousins will attest to Shimano’s reputation in disc brakes) leaving little to worry about when you want to go from fast to not-fast as fast as possible.

HED take care of wheel duties with the “Ardennes Plus GP”. At a claimed 1660g these are light, stiff, and a good workhorse race wheel to start out with for your disc brake collection. This tester had absolutely no issues with flex out on the road and they held their speed well.

Is it worth noting, the rubber on the S3d is Continental Grand Sport Race 23mm - which is unusual to see in this modern era of wider tyres. However, the range actually measure at 24.5mm. The rear clearance appears tight, but it can accomodate Vittoria and Schwalbe 25's. The rest of the build is as you’d expect.

An FSA Energy Compact bar and FI’ZI:K Antares saddle are sensible choices (although everyone has their own preferences in these departments) that agreed just fine with me and neat little details are abound. I’m a big fan of the flush integrated seat clamp, and although Red, White and Blue has become somewhat of a cliché for paint schemes on the S3 it oozes class. With the stem slammed and saddle set to personal preferences, it was time for the ultimate test.


It’s easy to make a bike look good on paper, but much harder to bring the intended ride quality to life. It can be difficult to quantify stiffness and compliance and geometry into real world traits that matter to a rider but fortunately this is where Cervelo excels.

From the first ride, it became apparent that the Cervelo is deceptively quick. Some bikes shoot forward like a cheetah on amphetamines when you put pedal to metal; they’re raw, they’re visceral, and they’re just a little bit scary. The S3d is not one of those bikes.

The S3d is statesmanlike in its composure. It sits balanced and poised on the road, moving forward without impediment. I put this down to the combination of a compliant rear, stiff frame and aero intentions. The latter is the hardest to quantify, but speed is a good proxy and Cervelo have certainly put plenty of that into this bike. After spending time on more endurance oriented bikes, the S3d felt familiar despite the slammed stem and aggressive appearance. Chip-sealed roads and debris filled shoulders weren’t a challenge for this bike; it treated them as minor annoyances rather than obstacles. I am of the belief that smooth is fast, and it seems Cervelo agree.


When putting down wattage that composure remains, expressed as a surge of power that will feel familiar to all who have sat in a jet plane during take-off. Far from frantic, it just feels unstoppable.

It’s all very well and good grinding and sweating your way up the hill as fast as humanly possible (and believe me, Cervelo have built this bike to take pleasure in that) but if you can’t make it down the other side of the hill at warp speed then really, what’s the point? This is where the through axles and disc brakes came into their own, keeping the bike tracking where I needed at the speed I wanted. Some riders have reported a bit of sponginess in these early generation Shimano Road Hydraulics but I didn’t find issue in this case, nor was any fade on longer descents with the 140mm rotors.

I was impressed by the tyres as well despite their 23mm width. I’m a big fan of higher volume tyres (my personal bike has 28’s) but the narrower option didn’t deter from the ride quality. I would still like to see more frame clearance in the interest of keeping the quiver killer spirit alive but as it stands this wouldn’t deter me from recommending this bike.

The rest of the bike was as expected for a bike of this calibre. The Ultegra drivetrain exhibited exemplary behaviour, the wheels didn’t wobble and flex on standing climbs, and the cockpit was a nice fit for this style of bike. Good choices all round.

So, who is this bike for exactly? One description Cervelo use is “Workhorse Unleashed” and it’s an apt one. I see this as the bike for the privateer with a reductionist attitude to things who wants one bike to get them through everything from a Criterium to a Classic. It’s stiff enough to sprint, smooth enough to ride all day, aero enough to keep up with the arms race that is the modern race bike, and thanks to the disc brakes can keep that all under as much control as desired.

Some will argue that a bike that scares you is also a bike that excites you, and that the composure on offer with the S3d is a detriment to truly enjoying the ride. But honestly, it’s hard to hear them say that when they’re at the back of the peloton and you’re off the front. If going fast is your thing, then the S3d is worth a look.