Reviewed: Cervelo S5 aero road bike

Cervelo's S5 performs admirably on the road, in the wind tunnel, and on the stiffness jig, but it doesn't come cheap at $10,000.

MSRP: $10,000
Weight: 15.8 pounds
Size tested: 56cm (Medium)
Overall Stars: 5/5

By the numbers, the Cervélo S5 was the most aerodynamic aero road bike that we tested in the wind tunnel this summer. Chalk it up to smart design based, in part, on rider feedback. On the road, the S5 just felt fast. Everything about it screams straight-line speed, from the tube shapes to the BBright bottom bracket. The only bike that felt faster was the Time Skylon, which we also tested this year, but the lab data shows that the Cervélo was actually faster.

The S5 felt stable and solid with optimal frame lateral stiffness, and the numbers from our stiffness testing back that up. It ranked in the top five of the stiffest bikes we’ve ever tested, but as far as we could tell, this didn’t translate into harshness out on the road. Like any aero bike, road vibrations can be jarring after awhile; this isn’t made for Roubaix cobbles.

In a straight line, the S5 performed well. It wasn’t the most confidence-inspiring in tight turns, but generally handled as well or better than the other bikes except for the Time Skylon, which felt a bit more precise diving into corners.

With an aggressive riding position, it seemed almost certain that back pain and neck and shoulder aches awaited our testers, but the S5 proved to be quite comfortable. A shorter head tube (15.7 cm) allows for a lower riding position, but even for grinding sections of road, we found this bike to be comfortable. The broad, wing-style handlebar provides a nice resting spot for the hands, in addition to providing an aerodynamic advantage.

As for acceleration, the S5 gets up and goes. A big, stiff bottom bracket transfers power very well, and a decently stiff head tube lets you really wrench on the handlebars for a lively sprinting feel.

It’s always hard to stomach a price tag that creeps over the $10,000 mark. The S5 has everything you’d expect for a bike at this price, from Dura-Ace Di2 to all the carbon you can dream of. While it may take refinancing the mortgage to attain it, the build seemed appropriate. You can pick up the same frame with a less expensive Shimano Ultegra group and low-profile wheels for just over half the price — $5,500.