Primoz Roglic uses gravel groupset in Giro d'Italia queen stage

The Queen stage of this year's Giro d'Italia is a hilly one, with a full five categorised mountain climbs and plenty more stabby uncategorised ones besides. In advance of the final time trial, a stage of two halves with a flat opening followed by an ascent of Monte Lussari, Primož Roglič's spare bike was spotted atop the team car sporting a single front chainring and a truly enormous cassette.

While we were speculating as to the setup, and why the bike was on the car today in advance of TT, Roglič proceeded to stop in advance of today's final climb and swap bikes, before being paced back to the bunch by the ever-dutiful Sepp Kuss. 

A dry run on new equipment? A chance to test the bike change under lower stress before the big day? Likely both, along with the fact that, as today's stage also finishes up steep gradients, it is probably optimal for the high cadence style the Slovenian likes to employ.

Uphill time trial setup

What's been chanced on Roglič's Cervelo R5 then? From what we can see he's running a single front chainring, as has become de rigeur for time trial bikes of late, except with a much smaller chainring. 

To begin with the easy bit, the rear cassette has been swapped out for what looks like, from the black largest sprocket, a SRAM 'XPLR' XG-1271 model, part of the brand's XPLR gravel subset of the top-tier Red groupset, offering 10-44T and a gear range of 440%, an extra 50% or so greater range than that offered by even the wider-than-normal SRAM Red cassettes. 

The cassette is 1x compatible only, so the use of a single front chainring is necessary, as well as likely desirable, and leaves Roglič with the option of anywhere between 38t and 46t upfront. He will have also had to swap from the standard Red rear derailleur to the wider range XPLR model.

For now, we can only speculate as to which front ring he is opting for. Rumours on the ground suggest it's a 44T, but we're yet to see it close up to be able to confirm this. It's also understood that his crankset does still feature a power meter, absolutely vital in a time trial, mountainous or otherwise, even if his Slovenian opposite Tadej Pogacar attacked La Planche des Belles Filles without one in 2020. Lower gearing aside, this may also have aerodynamic advantages, a lower weight, as well as a combination of a better chainline and/or using bigger sprockets resulting in reduced chain deflection and lower drivetrain losses.