Tour Tech: why are pro riders using SRAM 12-speed set-ups that are unavailable to the public?

Both Movistar and Trek-Segafredo are riding team-issue only SRAM chainrings in this year's Tour de France. We look at the reasons why

tour de france tech
(Image credit: Getty Images)

Alejandro Valverde, at 40, is the oldest man in this year’s Tour de France. But that didn’t stop him showing up in Nice aboard an unreleased Canyon Aeroad equipped with SRAM chainrings big enough to eat your dinner off.

Clearly Movistar’s elder statesman still has the legs for another loop around France, selecting a huge 54/41t set-up for the race’s flatter stages. It’s not a gear-range for the faint-hearted. And it’s not a gear-range available to the general public.

Movistar made the switch to SRAM groupsets at the start of the 2020, ending their decades-old relationship with Campagnolo.

Like their Italian counterparts, SRAM produce a 12-speed road groupset, with the Movistar team using its RED eTap AXS offering. However, buy this groupset off-the-peg and the only road race-ready option is a 50/37t chainset (other options are 48/35t and 46/33t).

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The Spanish team began the year using these 'standard' chainrings. However, like members of the Trek-Segafredo outfit, the other WorldTour team sponsored by SRAM, riders quickly began experimenting with ‘team-issue’ chainrings in more conventional sizes.

Fast forward to this year's Tour and both teams are using larger SRAM chainrings that currently can’t be bought at your local bike shop.

In the mountains, Trek-Segafredo's team leader Ritchie Porte has opted for 52-39t chainrings with a 10-30t cassette on his Emonda SLR. If 52-10 sounds like a pretty tall gear, it is.

And here perhaps is the reason why the SRAM-equipped riders in this year’s race are running larger chainrings. They probably aren’t using that 10t sprocket.

Trek-Segafredo's Ritchie Porte shows off his 'team-issue' SRAM chainrings during stage 4 of the this year's Tour de France. (Photo by Tim de Waele/Getty Images)
(Image credit: Tim De Waele)

While SRAM designed their 12-speed road groupsets around that very starting sprocket, it appears for professional racers it’s not required.

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The reason, it seems, is drivetrain friction. There’s been plenty of testing done on the subject. Results show smaller chainrings paired with smaller sprockets produce more drag than a larger combination achieving the same gear ratio.

48x10t and 53x11t produce an equivalent gear inch but the latter, when ridden at the same speed, requires fewer watts to sustain it. In short, it's another marginal gain.

However for those of us not paid to race a bike, there's little need to tamper with SRAM's AXS groupsets. In fact, the science behind its 12-speed offerings makes a lot of sense for mere mortals.

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The 10t sprocket essentially moves a portion of the gear range from the front of the bike to the back. Bingo. Smaller chainrings and cassettes, with reduced jumps between gears, allowing riders to remain in the same chainring for longer. Which, in essence, is far more efficient.

But if you want to ride what the pros ride you may, at some point, be in luck. Production is mere speculation, but the larger chainrings Movistar and Trek-Segafredo are using at the Tour look very refined and have clearly progressed from examples spotted at races earlier in the calendar. 

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