The first stage of the 2023 Tour de France was relatively hilly, and Jonas Vingegaard (Jumbo Visma) used the 1X version of SRAM's Red e-Tap AXS groupset. However, unlike his Giro d'Italia teammate Primoš Roglic, he did not opt for the XPLR wide-range gravel cassette.

Jumbo-Visma, who switched from Shimano to SRAM this season, tried nearly all of SRAM's vast array of gear configurations, covering both 1X (only one chainring on the cranks) and 2X (two chainrings and front derailleur).

They tried this option in both road and time trial competitions, including the Classics, and used it in the mountains. Vingegaard is the first major GC contender in such a hilly Tour to use 1x, and the team has confirmed that he will use a 50-tooth front chainring and a 10-36, the largest cassette on the road. Wout Van Aert also used a 1X groupset, with a 10-33 cassette.

The 1X (one-by) groupset has gained popularity over the past 12 months, bringing a number of obvious advantages. Removing the second chainring and front derailleur and adding a chain catcher immediately reduces the bike's weight by approximately 250 grams and improves aerodynamic efficiency. An additional benefit is that a center chainline becomes possible, slightly increasing efficiency and allowing the use of very large chainrings, as seen on Victor Campanaz's classic bike.

Among the Jumbo-Visma riders, Wout Van Aert was the first to try this technique on the road, using this setup in spring classics such as Paris-Roubaix and Strade-Bianch. However, it was Roglic who made a big splash on the final stage of the Giro d'Italia when he switched to a bike equipped with an XPLR groupset with a 44-tooth single chainring and a 10-44-tooth wide-range cassette.

According to Jenko Drost, the team's head of performance equipment, Roglic's desire for a higher cadence was the main motivation for using this groupset, but the efficiency gains from using a larger chainring and larger cassette sprocket were a nice secondary effect. Despite Roglic's success, he did win the Giro, but suffered a 30-second panic caused by a chain fall. Cycling News has revealed that the same XPLR groupset will not appear in the Tour.

The transition to 1X groupset is most common in time trials, and Ineos Grenadiers also had a trial in this discipline with aero expert and former Hour Record holder Dan Bigam on the team staff. In time trials, the marginal gains in aerodynamics often make a big difference in the outcome and are often so flat that they do not require the low gears offered by small chainrings.

The main drawback of switching to 1X is the reduction in available gear choices, and this is where a large cassette comes into play. The wide-range cassette provides an easier "easy" gear at the bottom of the cassette, and the rider gets the "best of both worlds," albeit with the compromise of a larger step between each gear.

Interestingly, this is not the first time 1X has turned heads in the peloton: five years ago, in 2018, Aqua Blue Sport was given a 3T Strada bike that could only fit a single chainring. This was met with mixed reviews from riders, and the team disbanded later that season.

However, its resurgence points to the continued evolution of the collective mindset of professional cycling. Even further back, about 10 years ago, the 11-28 cassette was considered unnecessarily large and only a few riders used it in the high mountains. The 11-28 is currently one of the smallest cassettes on the market, and 10-33T and 10-34T cassettes are not uncommon.

SRAM representatives also told Cycling News that Vingegaard and his Jumbo-Visma teammates will continue to use the 1X groupset for "some" stages during the remaining three weeks of the Tour. If Vingegaard were to retain his title, it would certainly be a major medal for 1X.