Cervelo

S3 Ultegra Di2 R8050 Road Bike

Whether you're a lead-out man, the domestique who chases back breaks, or the team's designated sprinter, you can go faster on an aero bike. Aerodynamic drag accounts for as much as 90 percent of the overall resistance you encounter or a ride and less drag simply equals more speed. Imagine having that, plus a smooth ride, proper stiffness needed for rock-solid sprinting, refined geometry for sure handling, and some good looks for the cherry on top. Well then, you'd have the S3 Ultegra Di2 R8050 Complete Bike, one of the picks of our litter.

Cervelo honed the S3's aerodynamics after spending countless hours in the wind tunnel testing and refining designs. This particular model features full internal cable routing thanks to a new bar and stem that hides the brake and shift housing from the wind for improved aerodynamics. Additionally, the new frame profiles work together to reduce drag so you simply go faster. Cervelo calls this True Aero which combines these specific tube shapes, sizes, and design features to improve aerodynamic flow across the bike.

The most aero bike available is meaningless if it’s a wet noodle though, so thankfully Cervelo worked hard to increase the stiffness at the bottom bracket shell ensuring efficient power transfer and that every watt goes straight to the rear wheel. Just like every other Cervelo, the S3 uses its BBright shell which takes advantage of oversized frame tubes that are stiffer and lighter. With the BBright system, larger sized tubes are used at the seat tube, down tube, and non-driveside chainstay. The benefit is an increase in stiffness and pedaling efficiency while achieving a lighter weight frame that's compatible with all major bottom bracket standards. Stiffness doesn't just end there and Cervelo beefed up the head tube junction that conspires with its geometry for more confidence inspiring handling with impressive stability and precision when cornering and descending at speed.

Cervelo's mastery of carbon layups and construction techniques also allow it to reduce the frame's weight while making it stiffer. It uses advanced engineering software like Finite Element Analysis (FEA) that allows it to better understand exactly how each layer of carbon fiber is working and if it's being used properly. Its carbon expertise prescribes a specific frame layup by placing hundreds of individually cut plies of carbon in a mold in a certain order and orientation. By precisely cutting these plies, Cervelo makes the frame lighter while still achieving the desired strength and reliability.

Different areas of the frame experience different loads while climbing, sprinting, and descending; to better cope with these forces, Cervelo creates different layups by placing the fibers at different angles in specific areas for the desired metrics. In addition to reducing weight and maximizing strength and stiffness, the layup also gets credit for making the bike comfortable to ride—claims that Cervelo backs up with extensive in-house testing and real-world experience.

A fast ride is a smooth one and it's important to keep vibrations at bay if you plan on going fast for long periods of time. Excessive road noise transmitted to the rider has proven responsible for premature fatigue and since Cervelo uses specific frame lay-ups and tube shapes that help soak up road vibrations, it helps reduce fatigue on those long days in the saddle.

Lastly, this S3 saves 53 grams (or the equivalent of 6.9 Watts) over the previous version of the S3. Furthermore, Cervelo doesn't offer its S5 with rim brakes, so if you are looking for its most aero mass-start frameset available, this S3 rim version is where it's at.

This version benefits from Shimano's Ultegra electronic shifting that's reliable and precise season after season. This rim brake build keeps the weight low and its direct-mount brakes still do an excellent job of scrubbing speed while pinching the aerodynamic Novatec R5 Carbon Clincher 48mm wheels. Cockpit choices come from Cervelo adding durability and a bit of value to this bike.