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Gravel Gear

Cervélo Áspero-5 review: A purebred gravel race bike

The wind tunnel meets the windswept plains in Cervélo's hyper-aero gravel racer.

Review Rating


Basics

Cervélo updates its original gravel race bike with front-end integration, its own bar and stem, and a D-shaped seatpost — all upgrades that improve performance without hampering adjustability.


Pros

Light, aero, fast, well thought out front end

Cons

Not cheap


Our Thoughts

If you love aero road races bikes, you'll probably love the Áspero-5. If you are wanting to ride a lot of chunky trails and go bikepacking, this is not the bike for you.


Size Reviewed

56cm

Weight

18.6lb

Price

$7,100

Brand

Cervélo


On the gravel-bike scale of race to bikepacking adventure, the new Áspero-5 is on the hardnosed race end of the spectrum. Cervélo’s dirt aero rig is a 100% gravel race bike. And it’s a blast to ride.

The key update with this new “-5” iteration is the front end: Cervélo tucked the brake and shift lines insides the stem and head tube, for an ultra-clean and aero presentation to the wind. Hand in hand with this integration is Cervélo’s new AB09 aero handlebar, which is a smart mix of aero shaping, gravel design, and practicality.

Photo: Ben Delaney

Carrying over from the original Áspero, the long-and-low geometry offers stability on dirt roads while allowing you to mimic your road position with a stack height comparable to many road race bikes.

A common refrain I’ve heard about the Áspero is that’s “it’s basically a road bike.” Um, no; it’s not. It does allow you to get low on the bike, and this latest iteration has the type of aero integration familiar to road race bikes. But at its core it’s a purebred gravel race bike, with progressive gravel race geometry.

Related: Bike-handling geometry: ‘Stable’ vs. ‘twitchy’ explained

Lighter and faster than the original

Cervélo claims the Áspero-5 is 10 percent lighter than the original, with a 56cm frame weighing 920g and the fork another 375g.

The company also claims the new bike is 32g faster than the original, when wind tunnel tested at 30mph. This figure isn’t hard to believe, given that cables in the wind have been proven time and and again to be a significant source of drag by many companies in many wind tunnels.

Clean as a whistle. Photo: Ben Delaney

Complete bike weight of course depends on the build, and Cervélo is selling three complete machines: a $6,900 SRAM Force eTap AXS 1 in Purple Sunset and Black, a $7,100 Shimano  GRX RX815 Di2 in Purple Sunset and Black, and a $9,000 SRAM Red eTap AXS 1 Ltd. in Lime Shimmer. I tested the Black Di2 bike, which built with Reserve 32 wheels and 38mm Panaracer GravelKings weighs 18.5lb. Please note that these prices are slightly higher than listed in the video above, as Cervélo updated its prices just before launch but after the video was made.

It comes in six sizes, from 48 to 61cm.

New AB09 cockpit

The original old, standard routing from bar into frame Áspero used an Easton cockpit with standard brake and shifting lines run under the handlebar and into the frame at the down tube. In this new bikes, that’s all effectively hidden, with the AB09 bar sculpted to tuck the lines neatly into the underside of the bar and then into the stem.

The shape looks a little funky, but I found it to be quite comfortable on the tops, hoods, and in the drops. Photo: Ben Delaney

Wind tunnel engineers are often at odds with mechanics and bike fitters as to what good bike design is. The absolute fastest front end is completely integrated: a one-piece bar/stem with the lines run internally. But, um, what about adjusting for reach, angle, and stack?

So, many companies have decided on a compromise where the brake and shifter lines are effectively internal — at least to the wind and the eye at first glance — while still allowing for adjustability via separate bars and stems.

Here, the AB09 lets you have your cake and eat it, too, with killer aerodynamics and easy adjustability.

Chasing aerodynamics while maintaining adjustability is a challenge, and Cervélo did an excellent job here. Photo: Ben Delaney

Further, the shape and construction of the AB09 is well done, in my opinion. The tops are flattened but not extremely so (Cervélo’s initial aero bar was so wide and flat most riders wouldn’t wrap their thumbs around it; a no-no in my book). There is room to bolt on aero extensions (and run satellite shifters for both Shimano and SRAM). And while the flare allows for more triangulation when in the drops, the shifters remain fairly vertical instead of tipped out at an extreme angle. So, you’re narrow n’ aero when on the hoods, and then more stable when in the drops.

Frame geo, features, and handling on dirt

The bike retains the ‘Trail Mixer’ chip, which lets you switch between 700c and 650c wheels without kertwangin the trail figure. With 700c wheels, you can fit 45mm tires with 4mm of clearance on either side. (In the video, I say Cervélo recommends a 42mm, which was the company’s initial cautious statement on max width.)

While many gravel bikes opt for very slack front ends (with head tube angles in the 70 to 71-degree range) and keep top tube length similar to road bikes, Cervélo extends its top tube (57.5mm on this 56mm tester) and keeps the head tube at 72 degrees. As built, the trail is 58.6mm, which is on the faster end of things, compared to a more steadfast 71mm on the Salsa Warbird and the Giant Revolt.

The bike’s handling is relatively quick, yet stabilized a bit with a longer top tube. Photo: Ben Delaney

The end result is a stability on dirt at speed with a sleepy or sluggish feeling. Specialized and Trek have done something similar,  with the head tubes on the Diverge and Checkpoint being steeper than 72 degrees and the trail figures being 58mm and 61mm respectively.

The bottom bracket also sits relatively low, with 76mm of drop — the same as the Checkpoint, which is more than most all bikes save the Diverge at 85mm. A low bottom bracket means stability, too — although pedal clearance can be compromised when pedaling through corners or on off-camber sectors. Since gravel racing is 99% a flat affair (I’m talking road surface, not elevation), you don’t need high clearance like you would for cyclocross.

I tested the bike on the flats and mountains around Boulder, Colorado, and down in Arizona on the Spirit World 100 gravel race course.  I was able to easily replicate my road position on the bike, which was a marked contrast from some of the other bikes I was testing at the time, most notably the BMC URS, which is an excellent machine but very much an upright proposition.

A rubber bashguard is a good idea, and you can bolt on a third cage down here, too. Photo: Ben Delaney

Responsiveness is excellent without the bike feeling nervous. It’s not as absolutely as plush as, say, a titanium bike like the Mosaic GT-1 I was testing, but the 27.2 carbon post is forgiving enough.

When riding blind behind a truck for filming, I felt comfortable on the hoods and in the drops; the position feels like a road bike, but the handling is so much calmer.

Reserve wheels, Panaracer rubber and build

Cervélo is part of the PON family that also includes Santa Cruz. The Reserve 32 wheels are the gravel-specific offerings from PON’s house wheel brand, a collab between Santa Cruz and Cervélo engineers.

At 24mm internal, the wheels are plenty fat for modern gravel, especially for the 38mm Panaracer GravelKings that Cervélo specs on this bike.

Panaracer rubber on the excellent house brand Reserve wheels. Photo: Ben Delaney

The wheels are named for their rim height, which should offer some aero benefit without crosswind sketchiness. I certainly didn’t feel any ill sidewind affects while ripping around the desert.

As for durability… go watch this video of Danny MacAskill doing the things that only Danny MacAskill can do to test their construction. I certainly didn’t knock the wheels out of true during any of my much more pedestrian antics on the bike.

This Shimano model comes with a front derailleur, which is not what the mustachioed kids are riding on Instagram, but something that still works exceedingly well for quick changes at the tops and bottoms of hills. This bike is built with a 48/31 crankset and an 11-34 cassette.

The rubberized chainstay guard is a welcome touch, although the GRX clutch does a good job of minimizing chain slap.

I love the GRX Di2 group for a few reasons: dependability in shifting and braking, ergonomics of the hoods, and the cool little thumb buttons that can control your Garmin if you buy a little D-Fly plug-in.

This bike also comes with a 4iiii dual-sided power meter. My test bike didn’t have a functional meter installed, so I can’t commit on its performance, but I do appreciate high-end bikes coming with integrated meters. The Force bike does not come with a meter, but the $9,000 Red bike does include a Quarq meter.

The bike comes in 6 sizes, from 48 to 61.

I found the padded Prologo saddle to be comfortable and similar to my preferred Specialized Power. One rail became dislodged from the base and started creaking quite a bit. I would hope Cervélo would replace it should the same thing happen to you. Photo: Ben Delaney

Áspero-5 bottom line: A ripping gravel bike

Cervélo doesn’t make cheap bikes. And the Canadian company doesn’t make an enormous range of bikes. What they do make, and often very well, are straight ahead race bikes for a specific purpose, be that on the road, for triathlon, or, here, for gravel racing.

Sure, speeds aren’t as high in gravel as they are in road. But in gravel racing the chances of finding yourself alone or in a small group for hours is much, much higher than it is in road racing. And there, you better believe aerodynamics makes a difference. So if you value that, plus great handling and a low, road-like position, then the Áspero-5 is absolutely worth your consideration. Just keep in mind that this isn’t a jack-of-all-trades bike; it’s a straight-up gravel race machine.

Photo: Ben Delaney