Cervelo S5 Red XPLR AXS 1 Bike

Pure speed — that is Cervélo’s brief for the S5, and the new generation delivers it in measurable terms: 6.3 watts faster than its predecessor, 124 grams lighter, and carrying the race results to back up the aerodynamic claims. Jonas Vingegaard, Wout van Aert, and Simon Yates have all ridden the S5 to major victories. The Cervélo S5 Red XPLR AXS 1 Bike pairs that platform with an unusual and genuinely useful specification: SRAM Red XPLR, a 13-speed single-ring drivetrain with a 10-46 cassette that turns the world’s fastest aero road bike into a machine that can handle any terrain you’re willing to point it at.

The aerodynamic gains on the new S5 come primarily from the front of the bike. The fork legs are deeper, the head tube profile is refined, and the all-new HB19 one-piece carbon bar and stem builds on Cervélo’s original V-stem concept with a “Plus-Four” design: the hoods sit 4 centimeters narrower than the drops, encouraging the rider’s upper body into a more aerodynamic position during sustained efforts without sacrificing stability in sprints. The full rear of the bike benefits from the asymmetric profiles of the S5 seat tube, which were designed to work with the Reserve 57/64TA wheel shapes as a cohesive aerodynamic system — not independent components that happen to be installed on the same bike. Cervélo co-developed the Reserve 57|64 wheels specifically for the new S5; they deliver 3 watts of aerodynamic improvement over the previous Reserve 52|63 model. Both hubs are DT Swiss 180.

The “XPLR” designation is the key differentiator of this build. Where the standard S5 Red AXS uses a conventional road cassette (10-33, 12-speed), the XPLR version runs SRAM Red XPLR’s 13-speed 10-46 cassette — a range that would be unremarkable on a gravel bike but is genuinely surprising on an aero road platform. Paired with a single 50-tooth front ring, the result is a 1x drivetrain with no front derailleur and a gearing range that goes from sprinting at 35+ mph to climbing grades that would strand a conventional race bike. The crankset includes an integrated power meter. The bottom bracket is a SRAM DUB Ceramic unit in Cervélo’s BBright shell — the proprietary wider BB standard that improves lateral stiffness and power transfer. A Hammerhead Karoo GPS computer is included.

The frame geometry is consistent across all six sizes: 73-degree seat tube angle throughout, 55.6mm trail constant across the size range, and 405mm chainstays from 48 to 61cm. Stack runs 496 to 608mm, reach 367 to 409mm. Nine bar and stem size combinations are available through Cervélo’s Authorized Retailer program at no additional cost — the right cockpit configuration for the rider’s proportions is part of buying an S5, not an afterthought. The build is UCI-legal. Color is Carnelian, exclusive to this XPLR specification.

Specs at a Glance

• Frame: Cervélo S5 Carbon Aero, 6.3W faster than predecessor
• Fork: Cervélo All-Carbon Bayonet S5
• Headset: FSA SL IS2
• Seatpost: Cervélo SP34 Carbon
• Cockpit: Cervélo HB19 Carbon One-Piece Bar/Stem (Plus-Four design)
• Drivetrain: SRAM Red XPLR AXS E1 1x 13-speed (wireless)
• Crankset: SRAM Red 1 AXS E1 with Power Meter, 50t
• Cassette: SRAM Red XPLR E1 10-46, 13-speed
• Bottom Bracket: SRAM DUB Ceramic BBright
• Brakes: SRAM Red E1 Hydraulic Disc
• Rotors: SRAM Paceline X Centerlock
• Front Wheel: Reserve 57TA / DT Swiss 180 / Tubeless / 12x100mm
• Rear Wheel: Reserve 64TA / DT Swiss 180 / Tubeless / 12x142mm
• Tires: Vittoria Corsa Pro TLR G2.0 700x29
• Saddle: Selle Italia NOVUS BOOST EVO SuperFlow Carbon
• Computer: Hammerhead Karoo (included)
• Pedals: Not included
• Sizes: 48, 51, 54, 56, 58, 61cm
• Color: Carnelian (exclusive to XPLR build)

Design Benefits

1. 6.3W aero gain with co-developed Reserve 57/64 wheels — The new S5 is faster than its predecessor primarily at the front end — deeper fork legs, refined head tube, and the HB19 Plus-Four cockpit. The Reserve 57/64 asymmetric wheelset was developed alongside the frame to work as an integrated aerodynamic system, adding 3 more watts over the previous Reserve 52/63 model. Cervélo backs this with real-world wind tunnel and on-road testing rather than idealized headwind conditions.
2. SRAM Red XPLR 13-speed 10-46 cassette — The defining specification of this build. A 10-46 cassette on a 50t front ring puts extraordinary climbing range on the world’s fastest aero road platform — the ability to ride steep alpine stages, mixed terrain, or heavily varied routes without switching bikes. The 13-speed spacing keeps gear steps reasonable despite the expanded range.
3. 1x drivetrain with no front derailleur — The single-ring setup eliminates a component, removes drag at the front chainring area, and simplifies race-day decision-making. The XPLR rear derailleur handles the full 10-46 range reliably. SRAM Red AXS provides wireless electronic shifting from the hoods.
4. HB19 Plus-Four one-piece carbon cockpit — The integrated carbon bar/stem positions the hoods 4cm narrower than the drops, creating a narrower frontal profile when the rider’s hands are on the hoods. Nine size combinations are available through Cervélo’s authorized retailer program at no extra cost.
5. BBright shell with ceramic DUB bearings — Cervélo’s BBright asymmetric wider BB shell improves lateral stiffness and power transfer compared to conventional road standards. The SRAM DUB Ceramic bearing set reduces friction at the highest-load point in the drivetrain.
6. Hammerhead Karoo included — The Karoo is a premium GPS head unit with a large display, long battery life, and best-in-class navigation. Including it as standard spec means this bike is truly complete from delivery: power meter, aero wheels, and navigation hardware are all in the box.

Final Take

The Cervélo S5 Red XPLR AXS 1 is the fastest aero road bike in the lineup configured for riders who refuse to be constrained by terrain. The 6.3W faster S5 platform, 1x SRAM Red XPLR with 13-speed 10-46 gearing, Reserve 57/64 co-developed wheels on DT Swiss 180 hubs, HB19 carbon cockpit, ceramic BBright BB, integrated power meter, and Hammerhead Karoo — this is a complete, race-ready build in the Carnelian color exclusive to this configuration. For the rider who wants the most aerodynamically advanced road bike and the gear range to use it everywhere, this is that bike.