New Cervélo Áspero 5 is 'the world’s most aerodynamic gravel bike'

Cervélo’s new Áspero 5 is a radical departure from the Áspero template that debuted in 2019. While last year’s update was more of an evolution, the 2025 overhaul sees the premium Áspero 5 model join the R5, S5 and P5 as an aerodynamically optimised pure-bred racer.

The new Áspero 5 has already had an outing under the rainbow jersey of 2024 UCI gravel world champion Marianne Vos and will feature in this year’s UCI Gravel World Series.

With two premium SRAM XPLR-equipped bikes available at launch, plus a frame kit, and another model joining the ranks later this month, the Áspero 5 range is concise and somewhat premium. The Force XPLR bike is priced at £8,000 / $8,700 / €8,299 / CA$11,500 / AU$12,900.

The RED XPLR version is £10,000 / $12,500 / €11,499 / CA$16,950 / AU$18,00 and the frame kit (frame, fork, headset, HB16 bar, ST31 stem, SP27 seatpost) is £5,000 / $5,500 / €5,499 / CA$7,500 / AU$7,900.

The SRAM builds both use a mixture of AXS components, with SRAM Red AXS shifters, SRAM Eagle XX SL rear derailleur, SRAM Red 1x aero crankset and a power meter.

The gearing combines a large 48-tooth chainring and 10-52t 12-speed cassette on the premium Red AXS model. The Force AXS model gets the same gearing, but the Red components are replaced by new Force parts and an X0 derailleur and cassette.

All models use Reserve’s turbulent aero wheelsets with a 40mm-deep front rim and 44mm-deep rear.

• Read more: Cervélo Áspero 5 review: a rapid gravel racer that I wouldn’t take out in the mud

Aero is everything

The new bike was designed to be the fastest gravel bike on the market.

The Áspero 5's aero-optimised design sees full integration at the front end, while not resorting to a one-piece bar and stem. Instead, it uses a combination of the ST31 stem and a new carbon gravel bar called the HB16, which takes its inspiration from the AB04 bar seen on the 2015 S5.

The bar's deep wing-shaped top section includes an aerofoil section in front of the stem clamp that mimics a one-piece design, yet has the adjustability and choice of a standard two-piece setup.

Cervélo claims this detail alone results in a 6-watt drag reduction over the previous Áspero and Áspero 5.

Out has gone the twin-tip adjustable fork dropout, with the new fork having a deeper bladed shape and the crown of the fork locking into the head tube in a much smoother transition.

Instead of the twin-tip fork providing geometry adjustments, the new Áspero 5 was optimised to be run with different tyre sizes front and rear.

In the more aggressive racing position, the front runs a 40mm tyre and the rear 44mm. However, consumers will get the bike with the 42mm tyres front and rear, with the geometry slackened slightly, and the stack and reach growing by a couple of millimetres.

The rear-end frame shape takes far more inspiration from the current Cervélo S5 than it does the outgoing Áspero 5, with a truncated aerofoil tube shape and a deep curve that wraps and shields the rear wheel.

This flows into an oversized bottom bracket shell that blends into a deep-section down tube that incorporates a down tube storage compartment, as found on the P-Series triathlon bike and, more recently, the Caledonia 5.

Wind-tunnel proven

The new frame design and cockpit result in an improvement in aero efficiency by a huge 37 watts. Cervélo claims its wind-tunnel tests show the Áspero 5 is 36 watts more efficient than its nearest competitor, Ridley’s Kanzo Fast, and 46W more efficient than Trek’s latest Checkmate.

New Cervélo Áspero 5 geometry

The Áspero 5's geometry falls as you'd expect, very much in the race-ready category: a low stack, longer reach and steep seat angle. Cervélo says the Áspero 5 geometry is based on its racing all-rounder, the Soloist, ridden by Wout Van Aert in this year's Paris-Roubaix.

However, it has a slightly relaxed head angle and short fork offset. When using the same 42mm tyre sizes front and rear, which Cérvelo calls 'balanced geometry', the bike gets a little more of an endurance bent.

In the 'mixed geometry' incarnation, with different front and rear tyre sizes, the stack lowers, reach grows and the angles steepen for a more race-ready setup.

Balanced geometry

Mixed geometry

New Cervélo Áspero 5 frame details

The Áspero 5 comes with the same stripped-down ethos as the original Áspero, which launched with the mantra of ‘Haul ass not luggage’. That means no fork mounts, mudguard or fender provision, two bottle mounts, down tube storage, bento box mounts on the top tube – and that’s it.

The bottom bracket uses Cervélo's threaded T47 BBright standard, and the rear dropout is SRAM's Universal Derailleur Hanger. The aerodynamic seatpost is the SP27, the same design as found on the current Soloist.

Cervélo claims the frame kit is 66g lighter than the previous generation's 990g frame and 496g fork.

The frame is heavier, at 1,023g, due to its inclusion of down tube storage. The weight savings come from a lighter fork (393g), bar, stem and seatpost, according to Cervélo.

The frame and fork have clearance for 45mm tyres, up from the 42mm of the previous generation. However, that looks a little conservative in light of the current trend for ever-wider tyres of 50 mm+ and even the adoption of mountain bike race tyres for events such as Unbound.