Wout van Aert has played the role of key all-rounder domestique to Jonas Vingegaard again at the 2025 Tour de France, as he did in 2024.
While the Belgian rider has won nine stages over previous Tours, the last of those came in 2022, when he also scooped the green jersey.
He won stage 9 of this year’s Giro d’Italia, though, outsprinting Isaac del Toro on the Strade Bianche stage into Siena, so he hasn't missed out on Grand Tour wins in 2025.
Single-chainring setups have previously been spurned by many pros, but van Aert has been making extensive use of SRAM’s aero single chainrings at this year’s Tour.
New Cervélo S5
As with team leader Vingegaard, van Aert has been riding the freshly updated Cervélo S5 aero bike rather than the latest, as-yet-unlaunched Cervélo R5 we spotted at the Lille Grand Départ ride-ready for Matteo Jorgenson. Sepp Kuss has also been riding the bike on mountain stages.
We don’t have a weight for van Aert’s S5, but Vingegaard’s Cervélo S5 with a single-chainring SRAM Red AXS drivetrain weighed 7.385kg. While Vingegaard is 1.75m tall, van Aert is 1.90m, so his bike will be heavier due to the larger frame.
We weighed Jorgenson’s Cervélo R5 at 7.03kg, suggesting there’s a small weight penalty of a couple of hundred grams from riding the S5, although in compensation it will be more aerodynamically efficient.
Single-chainring drivetrain
There are more potential aero gains from running SRAM’s single aero chainrings and skipping the front derailleur.
Van Aert, like Vingegaard, ran a 54-tooth single-chainring SRAM Red AXS groupset for the relatively flat stage 1. He’s since been swapping back and forth between 1x and 2x, choosing 2x for the mountain stages, but riding with a single aero chainring on the lumpy stages 11 and 15 – and even on stage 7 with its double ascent of the Mûr-de-Bretagne.
Van Aert's single-chainring setup includes a Wolf Tooth chain guide, as used by Vingegaard too, to help keep the chain in place. Van Aert runs 172.5mm cranks – a fairly standard crank length, although on the shorter side for a rider of his height. The Flattop chain is wax-treated.
Van Aert is riding Wahoo Speedplay Aero pedals, with a dimpled lower surface that’s claimed to improve airflow over the base of the shoe.
New one-piece cockpit
New for the latest Cervélo S5 is a single-piece cockpit, replacing the previous model’s two-piece design and claimed to save around 100g in weight, plus another 19g for the cockpit hardware. The 40mm flare to the bar contributes to a slightly turned-out lever position and better rider aerodynamics when riding on the hoods.
New Reserve wheels
Van Aert was running the latest Reserve 57|64 Turbulent Aero wheelset, developed in tandem with the new S5. Reserve says the new wheels offer better aerodynamics and are stiffer than the 52|63 wheelset sold with the previous-generation S5, without adding extra weight.
Visma-Lease a Bike has been trialling a carbon-spoked version with Tune hubs at the Tour, but van Aert's bike has standard steel spokes and the Reserve rims are laced to DT Swiss 180 hubs, the brand’s top model.
Classic saddle
Another contributor to the latest Cervélo S5’s weight loss is an updated saddle-clamping mechanism with a carbon cradle and alloy hardware. Cervélo claims this saves 27g.
Van Aert tops this off with a Prologo Zero II saddle on the brand’s Nack carbon composite rails, which has a claimed weight of just under 200g.
Specs | Wout van Aert’s Cervélo S5 for the 2025 Tour de France
- Frameset: Cervélo S5
- Groupset: SRAM Red AXS with 10-30t cassette
- Wheelset: Reserve 57|64
- Power meter: SRAM Red AXS, 54t
- Tyres: Vittoria Corsa Pro TLR Wide Rim, 29mm
- Handlebar: Cervélo S5 one-piece carbon
- Seatpost: Cervélo S5
- Saddle: Prologo Zero II Nack
- Bottle cages: Tacx Deva
- Pedals: Wahoo Speedplay Aero
- Weight: Not measured
