Cervelo S5 Dura-Ace Di2 Bike

The Cervelo S5 Dura-Ace Di2 Bike is what happens when a brand commits fully to aerodynamics and then keeps refining. The S5 isn't the lightest road bike Cervelo makes — that's the R5's job. The S5 exists to slice through the air faster than anything else at this price, and it does so with a precision that has made it the bike of choice for some of the best riders in professional cycling. Jonas Vingegaard and Wout van Aert have won races on it. Simon Yates has won races on it. The current generation is 6.3 watts faster than its predecessor while simultaneously shedding 124 grams — an improvement in two dimensions that doesn't happen by accident.

The aerodynamic gains are concentrated at the front end. Cervelo went significantly deeper on the fork legs and refined the head tube profile, producing smoother airflow into and around the frameset. The asymmetric seat tube profile integrates with the rear wheel as a cohesive system — air coming off the frame feeds cleanly into the wheel, not around it. This is not incidental. The Reserve 57|64 wheelset was co-developed with Reserve specifically for the S5's geometry, with the rear wheel's asymmetric profile engineered to match the seat tube cutout exactly. Those wheels are 3 watts faster than the previous Reserve 52|63 pairing while maintaining equivalent weight. Every aero gain on this bike compounds on the one before it.

The HB19 one-piece carbon bar and stem uses Cervelo's "Plus-Four" concept: the hood position is 4 centimeters narrower than the drops. This allows riders to hold a more aerodynamic position on the hoods — where most riding actually happens — without sacrificing stability during sprints or technical descents. Nine bar and stem size combinations are available, so achieving an aerodynamically optimized fit doesn't require compromise. The frame accepts those nine configurations at no additional cost when purchased through an authorized retailer, and the design is fully UCI-legal.

The drivetrain is Shimano Dura-Ace Di2 throughout — R9250 front and rear derailleurs with R9270 hydraulic disc levers and calipers. The crankset is Shimano Dura-Ace R9200 with a 54/40T chainring setup and a 4iiii Precision Pro GEN3+ dual-sided power meter installed from the factory. You are getting left and right power data without an aftermarket installation, and the chainring spec reflects what this bike is built for: top-end speed on flat and rolling terrain. The cassette runs 11–34T in Dura-Ace R9200 12-speed, giving enough range for variable terrain while keeping the gearing optimized for the kinds of courses where the S5 belongs. The bottom bracket is a CeramicSpeed SL in BBright spec — one of the highest-performing BB options in cycling, and it comes standard.

Design Benefits

1. 6.3 watts faster than the previous S5: A measurable, independently validated improvement — not a marketing estimate. The front-end redesign and deeper fork legs are where the bulk of those gains come from.
2. Reserve 57|64 co-developed for this frame: The rear wheel's asymmetric profile was engineered to match the S5's seat tube cutout exactly, creating a unified aero system. The result is 3 watts faster than the previous Reserve wheelset.
3. Plus-Four HB19 cockpit: Hoods 4cm narrower than drops means a more aerodynamic position wherever your hands actually are, with nine size configurations to dial in the fit precisely.
4. Dual-sided power meter from the factory: The 4iiii Precision Pro GEN3+ measures both left and right output, giving complete power data without an aftermarket installation.
5. CeramicSpeed BBright: One of the most efficient bearing systems in road cycling, spec'd from the factory on a $14,350 bike where it belongs.

Final Take

The Cervelo S5 Dura-Ace Di2 is a purpose-built aero road bike at the top of the category — and a complete one. Dual-sided power meter, ceramic bottom bracket, co-developed wheels, and a UCI-legal integrated cockpit that actually fits are all included. For riders who spend time on fast, flat courses and want the most aerodynamically optimized setup available at this price point, the S5 is the benchmark.