New Specialized Aethos: A 5.9kg Modern Do-It-All Road Bike

Today Specialized released the new Aethos road bike which breaks all the rules in the pursuit of ride feel.

During development, the engineers produced more than 100 000 CAD simulations mirroring different riding conditions to better understand how forces flow through the frame. At first, this process yielded a data monster. Once interpreted, the data revealed design trends that optimized ride quality.

From that point, they went into prototype phasing and Lead Engineer Peter Denk says: “The first frame was 545 grams. We put it on the test machine and the frame behaved so beautifully—it was so stable. We only had to add 10 grams, and we could test-ride the frame. That was the moment we knew we had discovered something big.”

The new Specialized S-Works Aethos road bicycle
The new Aethos is a high-performance road bike that is not focussed on racing.


The new Specialized S-Works Aethos road bicycle
Tube shape dictates performance | Specialized says the vast majority — like 75% — of the frame’s performance is dictated by shape. The remainder plays itself out in the actual materials used and the manner in which they are connected—the frame’s layup. The Aethos tubing is shaped to prioritize handling and ride feel.
The new Specialized S-Works Aethos road bicycle
Fewer layers | Through studying how frames move under load Specialized engineered a new way to lay-up frames. By using large, long and unbroken plies they achieved a more consistent layup and reduced the number of plies by 11% as compared to the S-Works SL6.
The new Specialized S-Works Aethos road bicycle
Wall thickness | The minimum wall thickness is just under 1mm and never exceeds 2mm.
The new Specialized S-Works Aethos road bicycle
Tyre Clearance | On a 21mm inner diameter rim Aethos has clearance for 32c tyres with 4mm to spare.
The new Specialized S-Works Aethos road bicycle
Weight and rider ratings | The Aethos is available in builds as light as 5.9kg’s and the bike is rated for riders up to 125kg.
The new Specialized S-Works Aethos road bicycle
Bottom Bracket | As much as 19% of the weight was saved by removing material in and around the BB area. As you can see, it is also a threaded BB.
The new Specialized S-Works Aethos road bicycle
Finishing | The Aethos has understated graphics, logos and colourways.

Stewart Thompson, Road & Gravel Category Leader:It was hard for many people here to wrap their heads around a high-performance road bike that wasn’t focused on racing. We were afraid that the project would meet resistance and get canceled, so our team worked in relative secrecy for over a year. No one knew about the project until the design was finalized, and we were making our first frames.”

Specialized says the outcome of Aethos represents an entirely new way of designing bikes for them and moving forward it will influence how they build all their bikes.


How much does the Aethos weigh? The S-Works Aethos uses our most premium FACT 12r material and layup to achieve a painted frame weight of 585g in the lightest colorways. The complete out-of-the-box weight of the S-Works Di2 model is 6kg in the Carbon/Chameleon Red Gold colorway.

What about the different colorways? The lightest frame colorway is the Satin Carbon/Jetfuel that weighs 585g. Other colorways will add roughly 25g (like Satin Carbon/Chameleon Red Gold or Satin Carbon/Gloss Black Chrome) to 45g (like Gloss Clay/Flake Silver or Satin Flake Silver/Chameleon Red Gold) more.

Is the new Aethos Rider-First Engineered™? Yes. Every frame size has the same legendary climbing responsiveness and descending prowess you’d expect from any of our Performance road bikes.

As a lightweight frame, is it still reliable? Aethos represents a new way of thinking about how to engineer a bicycle frame–like all Specialized production frames, it must undergo stringent testing to ensure it meets all quality and safety standards. In fact, due to the optimization of the tube shapes and layup, the Aethos frame is exceptionally durable, even as a lightweight bicycle. 

What is the geometry of the Aethos? The Aethos features identical fit and handling geometry as the Tarmac SL7. Detailed measurements can be found in the geometry chart.

How is stack and reach measured on the Aethos? Stack and reach are measured to the center of the top of the headtube, as is customary. Although these numbers are different than the Tarmac SL7, the fit geometry is identical between the two framesets.

What offset will the Roval Alpinist seatpost come in? The Roval Alpinist seatpost is available in a 12mm offset and in 300mm and 360mm lengths. All complete bikes and framesets will be spec’d with this Roval Alpinist post.

What build configurations is the Aethos compatible with? The Aethos is only compatible with hydraulic disc brakes. All models can be built with electronic drivetrains, but only the 10r framesets can be built with mechanical drivetrains.

Roval Alpinist Cockpit: Is it compatible? The Roval Alpinist Cockpit is compatible with all Aethos models and framesets. It was designed as a bar/stem combo to reduce weight, while giving riders the fit and performance they expect. It will be available in 10 different sizes (as combinations of stem length and bar widths) by early 2021.

Alpinist Cockpit: Is there an integrated computer mount? The new Alpinist Cockpit offers an integrated computer mount with compatible mounts for the following brands: Wahoo, Garmin, Polar, Cateye, and Bryton. Additionally, there is a mount designed around GoPro devices, Specialized Flux Lights, and a new mount designed for Specialized Stix lights.

What’s the largest tire size you can install on the Aethos? Every Aethos comes spec’d with 700x26mm tires, however, the frame was designed with much larger clearance in mind. You can fit tires up to 32c on 21mm rims with 4mm of clearance all around. Of course, this is all still dependent on the exact tire and rim combination as there is quite a bit of variation among tires especially. We suggest that you check fitment of the tire before you take it out for a ride

Can I remove the Front Derailleur Hanger? Yes! The Aethos has a removeable FD Hanger, which gives you the cleanest set-up when running a 1x drivetrain. If the FD Hanger is removed, a cover for the routing hole and two bolt holes is included with your Aethos. The hanger’s construction is different between the 12r and 10r frames, so please refer to the User Manual for proper installation.

Front brake caliper adaptor: Why is there a proprietary part? All Aethos frames were engineered to maximize the performance potential in the pursuit of the perfect ride–this includes optimizing the front disc brake caliper mount for 160mm rotors only. In doing so, the engineering team designed a new adaptor plate designed to work with any flat mount caliper to reduce the weight of the fork, without sacrificing any stopping power or reliability.

Where is the Shimano Di2 A-Junction Box? The Shimano A-Junction will be installed in the handlebar.

What are the other tech specs of the Aethos? All Aethos models have a 68mm BSA threaded bottom bracket. The Aethos has 142×12 and 100×12 thru axles and follows the Shimano flat mount disc brake standard.

Will Specialized sponsored race teams use Aethos? No. The Tarmac SL7 can be built and raced at the 6.8kg UCI weight limit and represents a significant aero advantage over Aethos.

Why is Aethos UCI approved? Although the Aethos can be built and ridden well below the UCI weight limit, UCI frame approval is still very important. This approval allows riders to utilize the Aethos as they wish, as many amateur events across the world require participants to use a bike that is UCI approved. UCI rules also dictate that these bikes each have a label in a conspicuous location permanently adhered to the frame.

No comment yet, add your voice below!

Add a Comment

Your email address will not be published. Required fields are marked *

Comment *
Name *
Email *