2025 Cervélo S5 on Test – Aero still rules the game!

The Cervélo S5 isn’t just about style and speed on two wheels – it’s all about performance. And for 2025, this race bike underwent a major update. But can you really improve a bike that already sets the benchmark for aerodynamics? Cervélo believe you can, and they’ve rolled out a thoroughly reworked S5. In our first test, we take a closer look to see whether the 2025 Cervélo S5 can raise the bar once again – and just how fast it really is.

The Cervélo S5 isn’t just any aero bike – it’s the very definition of speed on two wheels. Few bikes have racked up more victories in recent years, and in the hands of the pros at Visma Lease a Bike, the S5 has become the undisputed benchmark for aerodynamic performance. But for 2025, Cervélo stepped things up yet again. With new wheels, clever frame refinements and a lower system weight, the Canadian brand claim a gain of no less than 6.3 watts over the previous model. Sounds like full-on Tour de France vibes? Absolutely – and the timing couldn’t be better, with the launch coinciding with the start of the Tour. We’ve already put the bike through its paces to find out whether the new Cervélo S5 really has what it takes to chase yellow.

All about Aero? – Can the 2025 Cervélo S5 get even faster?

Hot on the heels of the Áspero-5 gravel race bike launch – which made a bold statement with its S5-inspired look – Cervélo are already lining up their next purebred racer for the start of the Tour de France. And what could be more fitting? It’s none other than a brand-new Cervélo S5!

Admittedly, the new S5 looks familiar at first glance. But according to Cervélo, every tube shape has been reworked and fine-tuned in the name of ultimate speed. As you’d expect, everything on the new S5 is designed with aerodynamics in mind. The frame has been subtly reshaped, most noticeably at the front, where a deeper head tube and a significantly lower, more streamlined fork underline the aero-first approach.

The seat tube, including the cutout, has been specifically optimised for the brand-new Reserve 57|64 wheelset. With 57 mm up front and 64 mm at the rear, the rims are slightly deeper than their predecessors ( 53 and 63 mm) but are said to weigh no more despite the added depth. The overall package is rounded off by a new one-piece cockpit. It retains the distinctive V-shaped design of the previous model but now features a more modern look, with a wider opening and a smoother transition between stem and handlebars – shaving off another watt in the process. A practical bonus: the new handlebars are compatible with older S5 models, which makes it easy to upgrade for existing owners.

More All-Rounder than Aero? – The 2025 Cervélo S5 sheds some Weight

But Cervélo weren’t just chasing aero gains with the new S5 – they also managed to trim a significant amount of weight. The full frameset, including hardware, cockpit and seatpost, is 124 g lighter overall. While the frame, seatpost and small parts have all been carefully refined for weight savings, It’s the redesigned cockpit that makes the most impact, shaving off a substantial 100 g. Interestingly, the new fork is actually 53 g heavier – but given the much deeper, more aerodynamic shape, Cervélo are more than happy to accept that trade-off.

Hidden inside the fork is some clever tech, with integrated hardware designed to reduce weight, along with a 160 mm brake mount. The revised seatpost comes with a new clamp that shaves off a few more grams while offering a wider adjustment range. It’s available in two versions, with 0 and 15 mm offset. Cervélo also introduced their own twist on the UDH derailleur hanger called éUDH, which is not only lighter but also UDH-compatible, making it ready for custom builds with SRAM RED XPLR. And that’s exactly where Cervélo see even more potential. According to the brand, running a 1x drivetrain could save a further 2 watts and bring down the weight even more.

The 2025 Cervélo S5 in Detail

Our 2025 Cervélo S5 test bike tips our office scales at 7.44 kg, retailing at € 13,999 – which makes it neither a lightweight nor a bargain. However, for your money you’ll get a full-blown high-end build. Outfitted with Shimano’s Dura-Ace Di2 groupset, including a 4iiii power meter integrated into the crankset, and rolling on Reserve 57|64 wheels with DT Swiss 180 hubs and 29 mm Vittoria Corsa Pro TLR G2.0 tyres, the S5 delivers a ride that feels straight out of the pro peloton.

If you prefer SRAM over Shimano, you won’t be disappointed. Cervélo offer two SRAM builds at the same price, giving you the choice between a classic SRAM Red AXS setup or the gravel-oriented SRAM Red XPLR with a 1x drivetrain. Both versions roll on the same Reserve 57|64 wheelset with DT Swiss 180 hubs. There are also two more affordable options available, equipped with either SRAM Force AXS or Shimano Ultegra Di2. Both feature a power meter, Reserve 57|64 rims and DT Swiss 240 hubs, and are priced at € 9,999. For riders looking to build their dream bike from the ground up, Cervélo also offer the frameset on its own in a range of colours, available for € 5,999.

The geometry of the 2025 Cervélo S5

The subtle updates to the 2025 Cervélo S5 continue into its geometry. While the changes are only minor, they’ve been carefully made to accommodate wider 29 mm road tires. The bottom bracket now sits 2 mm lower, while the fork features a slightly longer offset. Despite these tweaks, the S5 still delivers the same aggressive, stretched-out position it’s known for, thanks to its stack-to-reach ratio of 1.44. Up front, a 73.5° head angle gives the bike sharp, precise handling, while the 72 mm bottom bracket drop helps lower the centre of gravity for confident, stable cornering.

Size	48	51	54	56	58	61
Reach	367 mm	376 mm	384 mm	392 mm	401 mm	409 mm
Stack	496 mm	519 mm	542 mm	565 mm	588 mm	608 mm
Chainstay	405 mm	405 mm	405 mm	405 mm	405 mm	405 mm
BB Drop	74.5 mm	74.5 mm	72 mm	72 mm	69.5 mm	69.5 mm
Head Tube Angle	71°	72°	73°	73.5°	73.5°	73.5°
Seat Tube Angle	73°	73°	73°	73°	73°	73°
Top Tube	520 mm	535 mm	550 mm	565 mm	581 mm	595 mm
Head Tube	64 mm	82 mm	104 mm	125 mm	152 mm	173 mm
Wheelbase	973 mm	974 mm	975 mm	982 mm	999 mm	1013 mm

Pure Speed? – First Ride Review of the 2025 Cervélo S5

From the very first powerful pedal strokes, the deep Reserve wheels of the Cervélo S5 generate a distinct roar that makes one thing clear: this bike is built for speed. It picks up pace incredibly quickly on even the slightest descent and holds its speed effortlessly on level ground. When it comes to acceleration, the S5 takes two or three solid pedal strokes to really get going – but once it’s up to speed, it unleashes its full potential. With every additional kilometre per hour, the ride becomes more exhilarating, turning pure speed into pure fun.

Visually, the deep rims and wide, flat frame shapes make one thing clear – crosswinds are very much part of the equation. Even light gusts are enough to noticeably push the bike sideways. That said, the handling always remains composed and reassuringly direct. At high speeds in particular, the Cervélo S5 impresses with outstanding stability without ever feeling sluggish, responding to direction changes with sharp precision and minimal effort.

In terms of comfort, the S5 is a pleasant surprise given its stiff frame. Thanks to the 29 mm Vittoria Corsa Pro TLR G2.0 tires, the forgiving cockpit and a compliant seatpost, it offers far more comfort than you’d expect from a full-blown aero machine. Even when the road surface gets rough, the ride remains smooth and controlled.

Surprisingly, the S5 feels right at home on the climbs too. Thanks to the raised handlebars, the riding position is comfortable without being overly stretched, and at 7.44 kg, the weight is still quite reasonable for a bike with such a strong aero focus. That said, the bike isn’t without its flaws. Much like on the Áspero-5, the seatpost clamp fails to fully convince, with fiddly adjustment and slipping issues detracting from the otherwise excellent experience. Another drawback is the cockpit. On our test bike, it lacked the stiffness you’d expect from a top-tier aero race bike, which is particularly noticeable during sprints, where the front end felt a bit vague and less efficient than it should.

Who should take a closer look at the 2025 Cervélo S5?

With its aggressive look, deep-section wheels and striking cockpit, the S5 is guaranteed to turn heads – whether on your Sunday ride or lining up at a local road race. At 7.44 kg, it’s light for an aero bike, but it’s still not a true all-rounder. For long mountain days and rougher routes, there are better-suited options. The flex in the cockpit also remains a double-edged sword: while it adds a welcome dose of comfort, it can feel vague during all-out sprints, costing you confidence, precision – and potentially a few watts. But if you’re after an uncompromising speed machine, value comfort in your aero racer, and are ready to splash out on a premium ride, the S5 delivers one of the fastest and most distinctive road bikes currently on the market.

Conclusions about the 2025 Cervélo S5

The new Cervélo S5 stays true to its radical aero DNA, but targeted refinements have made it more modern – and even faster. With its composed handling, impressive efficiency and pure, unapologetic speed, the 2025 Cervélo S5 remains firmly at the front of the pack and continues to be one of the fastest bikes in the peloton. Thanks to a surprising level of comfort, it’s also perfectly rideable for us mere mortals – if it weren’t for the eye-watering price of nearly € 14,000 for the high-end Shimano Dura-Ace Di2 build.

For more details, visit cervelo.com.

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Words: Calvin Zajac Photos: Jan Richter