Why buy your bike from Sigma Sports?
Don't hesitate to reach out to us. It's our goal to answer all of your questions and offer the best advice from our experts. We’ll be happy to answer any questions you may have. Contact us now or visit us in-store.
All our bikes are fully built by our Cytech qualified mechanics. To find out more, see the Built, Checked, Tuned and Tested section below to see how we'll deliver your bike.
We offer FREE DELIVERY of your bike to your home or place of work. Once you've placed your order, our Customer Care team will be in contact to offer a convenient delivery date of your choice.
We've partnered with Pedalsure to offer you 30-DAYS FREE bike insurance on new bikes over £400. Visit our Cycle Insurance page to learn more and claim.
Product Highlights
FACT 12R is a lightweight and stiff carbon fibre that offers excellent levels of comfort.
Carbon clincher wheels, ideal for hilly terrain. They weigh 1248 grams and use a 33-millimetre deep rim.
A top of the range groupset, boasting 11-speed electronic shifting.
Body Geometry technology used in the Power saddle offers both comfort and performance.
Specialized S-Works Aethos Dura-Ace Di2 Disc Road Bike 2021
Specialized's S-Works Aethos is the lightest frameset they've ever made, with the frame coming in at a featherweight 588 grams (size 56). This road bike has been built up with Shimano's flagship electronic disc Dura-Ace Di2 components and Roval's lightest wheels - the Alpinist CLX. The idea behind the Aethos was to create the perfect bike, one that's not built for racing, but for the pure joy of riding, without compromising any of the performance of a top-end race bike.
The FACT 12r carbon layup and updated tube shapes are responsible for the huge weight reduction, and the bike sits below the UCI lower limit, without losing any of the stiffness or great handling that this material brings to a build. On top of this, you get the geometry and fit of the Tarmac SL7, alongside Rider-First Engineered™ design ensuring equal performance and ride characteristics from the smallest to the largest frame size.
The frameset is electronic groupset compatible only and Shimano Dura-Ace R9170 11-speed components make up the drivetrain, alongside hydraulic disc brakes. Shifting is precise, fast and easy to actuate by just a light press of the levers and stopping power is effective at speed even in wet conditions. Further shaving off the grams is Roval's Alpinist carbon seatpost, their lightest to date and the cockpit consists of an S-Works SL alloy stem and S-Works Short & Shallow handlebar.
Read more about the bikes in our Specialized S-Works Aethos article.
Highlights
- S-Works Aethos FACT 12r Carbon frame and fork
- Same fit and ride geometry as the Tarmac SL7
- Electronic cable routing specific frame
- 68mm BSA threaded bottom bracket
- Rider-First Engineered™ design
- Frame only claimed weight - 585 grams, size 56cm
- Shimano Dura-Ace R9170 hydraulic disc 11-speed components
- Dual-sided power meter
- Roval Alpinist carbon seatpost
- Roval Alpinist CLX wheels and Specialized Turbo Cotton 26mm tyres
- 32mm tyre clearance
Technical Specification
| Frame | Specialized S-Works Aethos FACT 12r Carbon, Rider First Engineered™, 68mm BSA threaded BB, electronic cable routing only, 12x142mm thru-axle, flat-mount disc |
| Fork | Specialized S-Works FACT Carbon, 12x100mm thru-axle, flat-mount disc |
| Bottom Bracket | BB-R9100 |
| Stem | Specialized S-Works SL, alloy, titanium bolts, 6-degree rise |
| Handlebar | Specialized S-Works Short & Shallow |
| Bar Tape | Supacaz Super Sticky Kush |
| Front Brake | Shimano Dura-Ace R9170, hydraulic disc |
| Rear Brake | Shimano Dura-Ace R9170, hydraulic disc |
| Brake Levers | Shimano Dura-Ace R9170 |
| Front Derailleur | Shimano Dura-Ace Di2 R9150, braze-on |
| Rear Derailleur | Shimano Dura-Ace Di2 R9150, 11-speed |
| Shift Levers | Shimano Dura-Ace Di2 Disc R9170 |
| Chain | Shimano Dura-Ace, 11-speed |
| Cassette | Shimano Dura-Ace CS-R9100, 11-30t, 11-speed |
| Crankset | Shimano Dura-Ace R9100, HollowTech 2, 11-speed, dual-sided power meter, 52/36T |
| Front Wheel | Roval Alpinist CLX, 21mm internal width carbon rim, 33mm depth, Win Tunnel Engineered, Roval AFD hub, 21h, DT Swiss Aerolite spokes |
| Rear Wheel | Roval Alpinist CLX, 21mm internal width carbon rim, 33mm depth, Win Tunnel Engineered, Roval AFD hub, 24h, DT Swiss Aerolite spokes |
| Front Tyre | Specialized Turbo Cotton, 320 TPI, 700x26mm, clincher |
| Rear Tyre | Specialized Turbo Cotton, 320 TPI, 700x26mm, clincher |
| Saddle | Specialized Body Geometry S-Works Power, carbon fibre rails, carbon fibre base |
| Seatpost | Roval Alpinist carbon seatpost |
| Pedals | Available to be purchased separately |
| Manufacturer Claimed Weight | 585 grams, frame only, size 56cm |
Built, Checked, Tuned and Tested
All our bikes are fully built, checked, tuned and tested by our Cytech qualified mechanics and then securely packaged, ready for delivery. All you have to do is add the pedals (if included), attach the handlebars to the stem and tighten them following the included detailed instructions or by watching our video and using the provided FREE tools. Visit our Bike Assembly page to see how you assemble your new bike once you receive it.
All bikes collected from our shop, are built, tested and ready to ride.
Please note, occasionally, manufacturers may change the specification without notice. Bicycles do not come with pedals unless otherwise specified. Bikes ordered for delivery will not arrive with the pedals installed, please refer to the owners manual and pedal installation guides provided for guidance. We do not install accessories to bikes, including mudguards. Bikes ordered for delivery that have tubeless compatible tyres and rims will arrive with inner tubes installed or with tubeless valves installed, this will be brand dependent. Sealant is available to be purchased separately.
If you require any assistance please contact our Customer Care team.