Specialized Aethos: First look, gallery and early review

What happens when a bike company stops the clock and ignores the rules of competition? The Specialized Aethos is a bike designed for the rider, not the racer

What is a hands on review?
Specialized Aethos
(Image: © Graham Cottingham)

Early Verdict

Our first impression is that Specialized's Aethos proves that rules were meant to be broken


  • +

    Extremely positive ride feel

  • +

    Incredible weight

  • +

    Beautiful finish


  • -

    Non-tubeless wheels

Why you can trust Cyclingnews Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.

What happens if the racing rule book is torn up and a bike is created not to be first over a finish line but instead focusing on creating a purer riding experience? The designers at Specialized conducted a year-long project in secret exploring what forms the essence of riding pleasure and how to create the best road bikes designed for the love of riding. 

The result is the new Specialized Aethos. A concept that goes against the status quo and may revolutionise how bikes are designed and built in the future.

The Aethos ethos 

Bike design is about marginal gains or at least that’s what has been preached to us from the upper echelons of cycling with aerodynamic improvements at the forefront of design. The introduction of aero road bikes with their elongated tubes was significant, but as refinements have been made almost every top-end road bike is now painted with the aero brush as they evolve in the hunt of an advantage. In the world of pro peloton bikes, the cycling industry has now returned full circle, Specialized’s new Tarmac SL7 dramatically put Specialized’s aero Venge out to pasture while still competing on the climbs with the best. The pursuit of speed is relentless, however, while companies focus on ever-decreasing micro gains to achieve any possible advantage over the competition there is a huge elephant in the room. 

The Union Cycliste Internationale is the world governing body for road racing and the UCI’s weight limit of 6.8kg has been strictly in place since 1999. This has meant race bikes, especially those from the last decade with advanced carbon construction, have been inherently compromised in performance. Whether the weight restriction benefits competition is a debate to be had another day, however, the everyday rider who is not bound by the authoritarian rule of the UCI has also been burdened by this weight limit. Blinded by racing blinkers, bike manufacturers in most cases focus on racing first and the consumer second, leaving paying customers to be force-fed bikes built to a limitation. For us mere mortals, the aerodynamic micro gains at 40km/h mean very little as we contest the local Strava KOM on a Sunday morning. 

What makes the Aethos so significant is Specialized’s design process, right from the start Specialized’s design team ignored the rules. Overbuilding the bottom bracket area to increase frame stiffness has been an accepted process of frame fabrication. However, when Specialized studied frame flex in its pedalling test rig they discovered this was only part of the story and the head tube area played a much more significant role than once thought. 

Instead of using supercomputer simulations to optimise aerodynamics, Specialized focused its computing power on tube shape. The resulting subtly conical tube shapes claimed to massively increase stiffness with a minimal amount of materials. This process may not result in a visually dramatic alteration in the frames form but Specialized believe it’s on to something significant. So significant that the Aethos heralds a complete shift in how Specialized bikes will be designed and will directly affect all future bikes.

Specialized didn’t stop at tube shape, carbon layup still plays an important role in the character of the frame. Continued study of the behaviours of the frame under stresses determined the possibility for a new carbon layup. The new tube shapes combined with a carbon lay-up using larger, longer, and more continuous, unbroken ply reduces high-stress areas by spreading load through the frame, Specialized describes this as 'no lazy fibres'. The results of Specialized’s efforts were evident right from the first physical frame, which weighed 545g and reportedly only required 10g of extra material to pass Specialized’s tests. With a final production weight of 585g +/- 5g (56cm, depending on finish), the Aethos is claimed to be the worlds lightest disc frame.


That builds up into a very light bike with the top of the range limited edition Founders Edition weighing in at a claimed 5.9kg. Our review S-Works Aethos Shimano Dura-Ace Di2 model comes in just a touch heavier at an impressive 6.1kg according to our scales. At S-Works level, no expense is spared although the component sheet is far from a weight weenie build making this overall weight even more impressive.

With so much consideration going into the frame, the Aethos deserves a lightweight wheelset to match and Specialized has turned to its component partners Roval, speccing the 1,248-gram Alpinist CLX wheels. The wheels are fitted with Specialized’s Turbo Cotton tyre in a 26mm although the frame has clearance for 32mm tyres should you need some extra cushioning.

The drivetrain is Shimano’s Dura-Ace Di2 which delivers flawless shifting as expected and has the addition of Specialized’s dual-sided power meter (courtesy of 4IIII) fitted to the Dura-Ace crankset. As this is a bike for the people, home mechanics can rejoice as the Aethos has a BSA threaded bottom bracket.

The recently released Alpinist bar and stem are also from Roval and was designed specifically for the Aethos. The bike is finished with a Specialized Power Pro saddle and a round Roval Alpinist seatpost with a regular seat clamp.

Beyond the spec, the bike is stunning to behold. The Satin Carbon/Chameleon Red Gold finish is beautiful, with deep sparkly reds and purples pick up light and further reveal themselves as you look closer. The logos and decals have been purposely kept to a minimum for a cleaner aesthetic, immortalised in gold/bronze coloured foil which further enhances the complete attention to detail and premium nature of this frame. 

First impressions

We have been lucky enough to have had the opportunity to ride the Aethos pre-release and, while we haven't put in enough miles to formulate a full review, first impressions have been extremely positive. Benefits from low weight are far more tangible to rider experience than aerodynamics and from the first pedal stroke, the low mass and instant movement forward feels special. This is by far the lightest bike I have ever ridden and the sheer ease at which speed is generated is spectacular. A big part of Specialized’s design process was for the Aethos to be uncompromised in real-world riding which means it must match it’s climbing prowess with descending capability. Geometry and handling has been lifted straight from Specialized’s dedicated race bike, the Tarmac SL7, and has so far been nothing but precise allowing pinpoint apex calculations through corners and beautiful weight distribution. 

When the SL7 was launched earlier in the year, Josh described it as a 'weapon of race destruction' in his Tarmac SL7 review, likening the SL7 to a lightweight Venge rather than a true descendent of the Tarmac line. With the new Aethos, Specialized may have found that lost Tarmac DNA and evolved it into a whole new species.  

Logbook: Specialized S-Works Aethos Dura-Ace Di2

  • Time: 3 weeks
  • Rides: 3
  • Mileage: 144km
  • Punctures: 0
  • Ride types: Road, rolling terrain

Specifications: Specialized S-Works Aethos Dura-Ace Di2

  • Price: $12,500 / £10,750 / AU$18,500
  • Frame: S-Works Aethos Fact Carbon 12R
  • Size: 54cm
  • Weight: 6.1kg
  • Groupset: Shimano Dura-Ace Di2 R9150
  • Crankset: Shimano Dura-Ace R9100 with Specialized Left-Right power meter
  • Wheels: Roval Alpinist CLX
  • Brakes: Shimano Dura-Ace R9170
  • Handlebar: Specialized S-Works Short & Shallow
  • Stem: Specialized S-Works SL
  • Seatpost: Roval Alpinist Carbon seatpost
  • Saddle: Specialized S-Works Power
  • Tyres: Specialized Turbo Cotton 26c

Thank you for reading 5 articles in the past 30 days*

Join now for unlimited access

Enjoy your first month for just £1 / $1 / €1

*Read any 5 articles for free in each 30-day period, this automatically resets

After your trial you will be billed £4.99 $7.99 €5.99 per month, cancel anytime. Or sign up for one year for just £49 $79 €59

Join now for unlimited access

Try your first month for just £1 / $1 / €1