Roglič swaps to 1x gravel bike groupset for final stage 19 climb

1x chainring paired with monstrous 10-44t cassette on queen stage of 2023 Giro d’Italia

By Jack Luke

Published: Friday, 26 May 2023 at 12:00 am

Primož Roglič (Jumbo-Visma) used a 1x SRAM Red AXS XPLR gravel bike groupset with a massive 10-44t cassette for the final climb on stage 19 of the 2023 Giro d’Italia.

The Slovenian made the change at the base of Tre Cime di Lavaredo, ditching his usual 2x SRAM Red eTap AXS-equipped Cérvelo R5 in favour of the same bike setup with a single ring.

1x drivetrains are common on time trial bikes, and are sometimes used on flatter races, particularly during the spring classics.

However, they are almost never seen in the mountains. So why would Roglič go 1x on a key climb?

1x in the mountains?

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Roglič made the swap at the base of the climb.
Tim de Waele/Getty Images

To start, with no front derailleur and only one chainring, a 1x setup is usually lighter than a 2x setup.

A 1x drivetrain is also, theoretically, more aerodynamic than a 2x drivetrain.

A single-ring setup can also be more mechanically efficient, with an improved chainline compared to a 2x setup.

Chain retention can also be improved with a 1x setup. However, given the smooth parcours of the climb, this is unlikely to have been a deciding factor.

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Roglič rode most of the race with his usual 2x setup.
Tim de Waele/Getty Images

All of these are marginal gains but, over the course of a 7.2km 7.6 per cent climb raced at WorldTour pace, they could add up.

That said, the time lost swapping bikes to then be dutifully towed back to the bunch by teammate Sepp Kuss may outweigh the theoretical time savings offered by a 1x setup.

A test ahead of stage 20?

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Stage 20 of the 2023 Giro d’Italia looks brutal.
RCS Sport

With that in mind, it’s possible Roglič had more pragmatic reasons for switching to the unusual setup.

Stage 20 of this year’s Giro d’Italia is an 18.6km individual time trial. After a flat opening half, the final 9.8km of the stage ascends 1,050m with gradients kicking up as steep as 22 per cent.

We expect many teams will swap to a lightweight climbing bike at the base of the climb.

It’s possible Roglič wanted to trial the 1x setup in a low-pressure setting ahead of using it in the penultimate stage of this year’s race.

Roglič finished stage 19 in fourth place, knocking 3 seconds off of Geraint Thomas’ GC (Ineos Grenadiers) lead.

A 1x renaissance?

Though they’ve become very common in time trials, it’s fair to say 1x road bike drivetrains have seen mixed success.

Aqua Blue Sport raced exclusively on 1x drivetrains until the team folded in 2018, with some riders specifically blaming the team’s downfall on its early adoption of single-ring drivetrains.