if you have been longing to ride Shimano's 12s-speed Ultegra Di2 on a fantastic road frameset but you don't want to break the bank, this is the bike you want. The Specialized Aethos Expert Ultegra complete bikes feature a frameset that is step down in carbon grade from the ultra-light S-Works frame, but at 699 grams in a 54cm (!), it is hardly a heavyweight and is still as light nearly any other production frame made. Although the Aethos design carries a race geometry, it was engineered and developed to offer the apex cycling experience for the serious enthusiast who appreciates the ultimate in quality and design, with the cleanest aesthetic, an incredible finish, and wondrous ride quality.

The story of the Aethos is pure Specialized. The achievement of the frameset design represents virtually all of the foundational principles of the company, except one. For one of the leading proponents of aerodynamic design for road cycling and racing, as exemplified by the Tarmac SL7, aerodynamics was never factored in to the development of the Aethos. Having struck the perfect balance between light weight and aerodynamics for the SL7 race machine, the engineering problem of building the lightest, most exceptional riding road bike was incredibly appealing. In order to crack it, new and more efficient applications of carbon fiber, as well as a new Continuous Curvature Design strategy were achieved. The end result of Aethos process pushed the most innovative team in cycling development to new heights and will certainly inform and impact the future. While the S-Works frame features the ultra-premium FACT 12r carbon, the Aethos Pro and Expert models have the more cost-effective FACT 10r layup.

The Aethos frame has been designed with the perfect combination of ultimate ride feel, light weight, and style. This was achieved by reinventing the traditional road tube shapes found on bikes of the past, subtly altering these visual shapes to deliver massive gains in stiffness and balance, all without affecting weight or durability. That visual story appears simple on some level, but it was the application of carbon technology and incredible engineering capabilities to find the stress loads, tube thicknesses, and how to best integrate all of the shapes and engineering requirements in ways you can't see to create the FACT 10r Aethos. This new process, with an entirely-new layup system tapped into the R&D system Specialized has perfected over multiple decades to be the most innovative company in cycling.

The creation and engineering story is ripe for a graduate course offering, so the discussion must turn the possibilities and rationale of the rider experience. A superlight frame is useless without confidence-inspiring ride characteristics, which is the team developed the Aethos to have the perfect balance of front and rear stiffness combined with exceptional overall ride quality. By studying the flexing and breathing of carbon fiber, the testers were able to discover groundbreaking findings about how forces flow through frames. With just a few firm pedal strokes you’ll realize this sublime ride sets a new standard. Every detail has been designed with style, weight, and durability in mind, everything required in pursuit for the perfect ride. The geometry is exceptionally close to that of the Tarmac SL7, with a few modifications that may add up to a subtle handling difference if you were comparing each bike built with the same exact kit.

The electronic shifting-only Aethos frameset is equipped with a 27.2mm round seatpost, the Roval Alpinist to be exact, which offers some engineered flex into the upper portion that adds to the frame compliance and weighs a scant 136 grams in the 300mm length. Not to worry, it (and the frameset) is rated for a rider weight up to 275lbs. The frame and fork can accommodate tires up to 32mm with 4mm of clearance on both sides. The fork steerer is round, accepting standard stem and bar set-ups. Every line, every junction just feels so economical and judicious in the use of materials. Again, no real aero impact, as even the internal wiring set-up avoids the headtube integration mechanics quiver over. Still, the system is clean, simple, and looks totally inline with the Aethos concept. There isn't a single detail on the frame that has been overlooked. It is an amazing frameset: stunning, brilliant, and eminently rideable, which is truly the best part.

Shimano's updated Ultegra R8170 Di2 components deliver impeccable electronic shifting and all conditions disc braking with wireless signal from the shifters, while the derailleurs are each wired directly to the seatpost battery for longevity and reliability. Specialized and Roval supply the build kit, with carbon wheels and all-around quality. This 2022 Aethos Expert Ultegra Di2 build offers incredible value in a complete bike, with tremendous performance and a riding experience you'll long for before every ride.