Hardly any aerodynamic features, limited cable integration and mounting points for only two bottles: the list of things that the Specialized S-Works Aethos doesn’t have is long. Does this minimal concept work during the test or does this bike not stand a chance against the competition? Find out here.

For an overview of the test fleet head to the group test: The best road bike of 2021 – 15 models in review

Specialized S-Works Aethos | 6.49 kg in size 56 | € 12,999 | Manufacturer’s website

According to Specialized, road bike fans who are after more than just a purebred racing machine were the primary focus during the development of the S-Works Aethos. In turn, the premium FACT 12r carbon frame of our test displays hardly any obvious aerodynamic features. The comparatively delicate-look bottom bracket area is fitted with a 52/36 t Shimano DURA-ACE chainset with a standard BSA bottom bracket. Even the clamp for the 27.2 mm Roval Alpinist carbon seatpost comes across almost as traditional. Only the contrast with the one-piece Roval Alpinist carbon cockpit and the Roval C38 gravel wheels will awaken interest amongst keener eyes. So what makes this concept so special? The keyword is reduction. Instead of constructing the frame in the usual manner with reinforcements but also increased weight in key areas like the bottom bracket and down tube, the Aethos frame is constructed more homogeneously. Nonetheless, there are no sacrifices in stiffness where it matters. For the new S-Works, the top tube rather than the down tube is the key structural element in the system, with Specialized’s engineers apparently having taken steel frames as their inspiration.

Good for non-alpinists too
The ergonomics and comfort of the one-piece Roval Alpinist cockpit with 420 mm wide bars and 100 mm long stem convinced the whole test crew. The tidy look and integrated GPS mount round out the package.
In the Specialized universe, SWAT stands for Storage, Water, Air and Tool – everything you need for your ride. The Specialized Road Bandit stores tire levers, a tube and a CO2 cartridge and attached to the mounting points on the base of the saddle.
Everything but a downgrade
For our test bike, Specialized didn’t fit the superlight Roval CLX Alpinist wheelset but the heavier, tubeless compatible Roval C38 wheels from their gravel range. That offers security and additional stability at the limit.

Specialized S-Works Aethos 2021

€ 12,999


Seatpost Roval Alpinist Carbon 12 mm
Brakes Shimano DURA-ACE BR-R9170 160/140 mm
Drivetrain Shimano DURA-ACE Di2 R9150 2 x 11
Chainring 52/36
Stem Roval Alpinist 100 mm
Handlebar Roval Alpinist 420 mm
Wheelset Roval C38 12 x 100/12 x 142 mm Thru-Axle
Tires S-Works Turbo 30-622 (700x30C) 32
Cranks Shimano DURA-ACE FC-R9100 172,5 mm
Cassette Shimano DURA-ACE CS-R9100 11–30

Technical Data

Size 49 52 54 56 58 61
Weight 6.49 kg

Specific Features

lightest bike in the group test
SWAT storage system on the saddle
dual-sided Specialized power meter
Alpinist cockpit with integrated GPS mount

Everything under control
The dual-sided Specialized power meter helps you to stay under your limit. That won’t just help pros but also leisure riders who want to reach their destination enjoyably and without suffering.
An icon in the making
Regardless of whether it’s the bottom bracket or the junction between the seat stays, seat and top tube: the FACT 12r carbon frame combines classic tube shapes with modern visual features. A modern classic!
Don’t drink and ride
While the Aethos is a long way away from the racing bikes in Specialized’s portfolio, they’ve still gained UCI approval for the frame. We could happily have gone without and counter it with a hip flask. Chin chin at the end of the ride!

They’ve made sure that the Aethos can flex along the horizontal axis through corners allowing it to generate more grip, compliance and in turn an improved feeling of safety – a characteristic that inveterate steel frame fans all too often like to rave about. But really, the showstopper is that Specialized have managed to deliver all that at a weight of just 6.49 kg for our size 56 test bike. Though it would have been even lighter with the series Roval CLX Alpinist wheels, Specialized fitted our test bike with the robust and heavier C38 wheels due to their tubeless compatibility. Nonetheless, the Aethos is 330 g lighter than the next heaviest bike in this group test – the Wilier Filante. The accessories on our € 12,999 test bike like the King Cage bottle and hip flask cages, the SWAT Road Bandit tube mount and the Gramm Tourpacking Dyneema top tube bag are sadly not part of the series spec, but most definitely get our wholehearted recommendation!

Size 49 52 54 56 58 61
Seat tube 431 mm 462 mm 481 mm 504 mm 532 mm 567 mm
Top tube 508 mm 531 mm 540 mm 562 mm 577 mm 595 mm
Head tube 109 mm 120 mm 137 mm 157 mm 184 mm 204 mm
Head angle 71.8° 72.5° 73.0° 73.5° 73.5° 74.0°
Seat angle 75.5° 74.0° 74.0° 73.5° 73.5° 73.0°
Chainstays 410 mm 410 mm 410 mm 410 mm 410 mm 410 mm
BB Drop 74 mm 74 mm 72 mm 72 mm 72 mm 72 mm
Wheelbase 973 mm 975 mm 978 mm 991 mm 1,005 mm 1,012 mm
Reach 375 mm 380 mm 384 mm 395 mm 402 mm 408 mm
Stack 514 mm 527 mm 544 mm 565 mm 591 mm 612 mm
Helmet POC Ventral Air SPIN | Glasses POC Devour Clarity | Jacket Rapha Mechanics Jacket
Jersey Rapha Men’s Logo T-Shirt | Pants Rapha Men’s Cargo Bib Shorts
Shoes Specialized S-Works 7 Road Shoes | Socks Rapha Logo Socks | Watch Sinn 556 I

The Specialized S-Works Aethos in review

Step on the pedals and the Aethos is willing and light-footed like no other bike in the group test and can be brought up to speed immediately in any situation. Uphill and on long climbs it responds to every turn of the cranks with responsive drive, even if on very steep slopes you’ll need enough strength to keep on turning the pedals due to the large chainrings.

In the test field, there is no other bike that better combines the essence of cycling with the most modern technologies of the 21st century. The Specialized S-Work Aethos points the way ahead!

On the flats there are significantly more efficient bikes in the form of the MERIDA REACTO or the BMC, but does that harm your enjoyment aboard the Aethos? Our test crew unanimously says no! The S-Works magics a grin onto the face of riders of any ability like no other bike thanks to its intuitive and balanced handling. The perfect mix of direct, good-natured, stable handling and manoeuvrability seek their equal in this group test. Even on rough and broken up surfaces, the bike stays supremely capable, inviting experienced riders to play and simultaneously giving beginners the security to press on. Despite the low weight it stays planted on the road and feels like a bike that is much heavier. And yes, the parallels to cornering aboard a steel bike can’t be denied! While lightweight bikes generally result in significant compromises downhill, you always feel safe aboard the Aethos and can push your limits or simply enjoy maximum riding fun. In terms of comfort, the Alpinist setup consisting of the one-piece cockpit and seatpost, together with the frame’s compliance, deliver a convincing impression. Big hits are pleasantly defused and high-frequency vibrations strongly damped. The 700 x 30C S-Works Turbo tubeless tires also make an important contribution to the overall comfort of the bike with their good damping. Alongside the average efficiency on the flats, the only issues are the lack of mudguard mounts in an otherwise trendsetting and coherent concept.

Tuning tip: fit a complete set of Dyneema Gramm Tourpacking bags and set off on your big bike adventure of 2021!

Riding Characteristics



  1. cumbersome
  2. playful


  1. nervous
  2. confident


  1. demanding
  2. balanced

Fun factor

  1. boring
  2. lively


  1. firm
  2. comfortable

Value for money

  1. terrible
  2. very good

Technical Data

S-Works Aethos

Size: 49 52 54 56 58 61
Weight: 6,49 kg
Price: € 12,999

Indended Use

Smooth tarmac 1
Allroad/Gravel 2
Everyday/Commuting 3


No other bike in the test field combines light-footed acceleration, intuitive handling, long-distance comfort and maximum fun on all surfaces as well as the Specialized S-Works Aethos. It’s the most versatile bike in the test for everyone from leisure riders to racers, from beginners to pros and from lactate hunters to ice cream aficionados. A completely coherent package with proven handling and modern technologies: the best road bike of 2021. Best in Test!


  • balanced and intuitive handling
  • most light-footed and willing acceleration in the test
  • minimal weight without the usual disadvantages
  • high level of comfort


  • average efficiency on the flats
  • limited mounting point

For more information head to specialized.com

The test field

For an overview of the test fleet head to the group test: The best road bike of 2021 – 15 models in review

All bikes in test: BMC Roadmachine 01 ONE (Click for review) | Cannondale SuperSix EVO Hi-MOD Disc Ultegra (Click for review) | Canyon Grail CF SLX 8 eTap (Click for review) | Cervélo Caledonia-5 Dura Ace Di2 Disc (Click for review) | Mason Resolution Ekar (Click for review) | MERIDA REACTO TEAM-E CUSTOM (Click for review) | MERIDA SCULTURA ENDURANCE CUSTOM (Click for review) | OPEN MIN.D. (Click for review) | Orbea Gain M20i (Click for review) | ROSE REVEAL FOUR DISC Ultegra Di2 (Click for review) | SCOTT Addict eRIDE Premium (Click for review) | Specialized S-Works Aethos | Storck Fascenario.3 Comp Disc Ultegra (Click for review) | Trek Domane+ LT 9 (Click for review) | Wilier Filante SLR (Click for review)

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Words: Photos: Valentin Rühl