By and large, pro cyclists follow the tried-and-tested mantra when it comes to setting up their bicycles, and the same is true of their gearing. But just what gears do the pros use?
For many years pros have reliably stuck with 53/39t standard chainsets, because they race at very high speeds and need big gears. Most consumer bikes have moved over to 50/34t compact and 52/36t chainsets (or 48/35t and 46/33t on SRAM 12-speed groupsets paired with 10-tooth start cassettes), because us mere mortals aren’t blessed with the awesome talent of the pros.
(If you need a primer on the basics of gears and all the lingo, check out this article).
Cassettes have varied much more over the years, largely as a consequence of the steady increase in gears, from the old days of 5 and 6-speed to the 11- and 12-speed setups that are currently used in the pro peloton. As the number of gears has increased, so too has the range, with bigger cassettes increasingly common, partly as a response to race routes that are getting ever harder as race organisers attempt to find even more cruelly savage mountains to send racers up - take stage 11 today with a double ascent of Mont Ventoux, to give one brutal example.
A lot of pro riders will use non-standard chainring sizes, particularly sprinters so they have some extra oomph in the last 200 metres of a sprint finish. Above is an example of a 54/42 Shimano Dura-Ace chainset that we snapped on Peter Sagan's now defunct Venge back in 2019.
A 42t inner ring seems a little odd these days, but 20-30 years ago a 52/42t chainset was pretty standard.
On this bike, it was paired with an 11-28t cassette. That is positively humongous compared to the 11-21t cassette that was common a few decades ago when you'd be lucky if you got an 11-23t for the mountains. Since Shimano went to 11-speed though, the 11-28t cassette has become ubiquitous.
Why? Because 11 sprockets offer both increased range while maintaining small steps between the sprockets, ensuring the rider is rarely out of their optimum cadence range. It also means a lot less work for the mechanics because they’re not continuously swapping cassettes! (More time to bleed disc brakes then…)
Talking of cassettes, another trend we’ve noticed in recent years is the increased use of Shimano’s 11-30t option. It's the sort of cassette size you once only saw on amateur bikes, not pro race bikes. Above is Kasper Asgreen's Specialized Aethos that he's using on hilly stages (the Big S said the Aethos wasn't for racers, but such is life) and he's using a 54/39t chainset paired with the 11-30t cassette.
11-30t was introduced at Dura-Ace level shortly after the current iteration of the groupset launched, and was the biggest range cassette ever made at this high-end level - however Campagnolo offers 11-32t cassettes on its top-end Super Record EPS, and SRAM's 10-33t for Red eTap AXS goes even lower. With some of the steep climbs on this year’s route, plenty of riders will decide to go with wide-range cassettes from the off.
Trek-Segafredo's press officer Jacob Kennison told us that most, if not all of its riders will be using a non-standard 52/39 chainset paired with a standard 10-33t cassette for stage 11 - however Kennison says this set-up has been used throughout the Tour, which shows how versatile road bike gearing is now.
The number of gears on a road bike has increased over the years, with the cassette expanding from 6-speed back in the day to 11 -and 12-speed of today’s modern groupsets. Back in the old days, you’d be lucky if you had a 23t big sprocket on your cassette (imagining grinding up a mountain on that!) but today we’re looking at 11-30t or equivalent becoming common on pro bikes. For Trek-Segafredo, it appears the 12-speed SRAM gearing provides enough range for mountains and sprint stages alike.
In the past, we have noticed some riders going the opposite way to Peter Sagan and swapping out their inner chainrings for a slightly lower gear. On the Cannondale SuperSix Evo above, the regulation 53t outer ring remains, but the 39t inner ring is swapped for a 38t to offer a slightly lower gear in the mountains. One tooth might not sound much, but you’re looking at 1.27” as opposed to 1.30”. In a race where margins matter, it might make all the difference.
As we've already mentioned, SRAM is bucking the trend for big chainrings nowadays because of the 10t sprocket on its 12-speed cassettes. SRAM has sought to create a groupset that provides a wider range of gears with smoother gear progression (smaller gaps) via the use of the 10t and smaller chainrings. The biggest it offers as standard is a 50/37t chainset and 10-28t cassette, as seen on Alex Dowsett's bike above from the 2019 Tour.
However even that year when SRAM Red eTap AXS was quite new, we spotted some prototype larger chainrings on Trek-Segafredo bikes - and it seems like that has now caught on with the pros, as Trek-Segafredo riders are now using 52/39 chainrings.
Even if any pros do opt for a standard 50/37 it will hardly leave them spinning out, as the 50x10 maximum gear is bigger than a standard 53x11t groupset. Meanwhile, at the other end of the cassette, the smallest gear is lower, allowing for higher cadences on steep gradients.
Campagnolo-sponsored riders will have a similar choice of gears to choose from. A 53/39t chainset is common, with a smaller 36t inner chainring available for mountain stages. Cassette options include two choices, an 11-29t and 11-32t. Campagnolo’s latest groupset is 12-speed, and one benefit is that the first seven sprockets go up in single increments. That’s ideal for finding your perfect cadence.
The death of the front mech has been long speculated in some parts of the bike world, but it’s rarely spotted in the pro ranks. A few riders have dabbled with 1x, with varying levels of success, and of course, there was the ill-fated Aqua Sport Blue team which solely used 1x drivetrains on 3T Strada bikes - the team boss at the time was quite scathing about either the drivetrain or the bike, or perhaps both.
There are benefits to a 1x system. There’s less duplication of gears that you get with a 2x groupset, it can be lighter and more aerodynamic, and it’s arguably one less component to potentially fail, which makes it popular with time trial specialists racing on flat-ish courses (here the lower chainring will just be ditched though). But it hasn’t caught on where a wide range is needed for variable terrain, mainly because while the range on offer with current groupsets is agreeable, the jumps between the gears aren’t. There’s also the issue of the chain dropping off without a front mech to act as a retention device.
Today’s pro road racers are provided with equipment vastly superior to 10-20 years ago, but it’s the range of gears that have been the most interesting trend as the groupsets have evolved. As the number of sprockets has increased, the gear range has increased. Are riders getting soft, are courses getting harder, or are the wider gear ranges enabling ever harder courses to be raced on?
The three big groupset manufacturers are still focused on the needs of the pro racers and delivering groupsets to meet their needs, and then selling them to the public; but there just aren’t many normal people that need a 53-11 gear. The requirements of the pros are very different to people like you and me.
This is slowly changing though. Outside of the pro peloton, we're starting to see a shift in focus from the equipment manufacturers to meet the growing diversity of modern cyclists that are less influenced by pro racers and more by their riding, whether long-distance road rides or adventure and gravel bikepacking. Largely thanks to adventure riding we're now seeing much wider range groupsets with more realistically usable gear ratios for the many people that don't go racing every Sunday, but want gears to help them out on challenging terrain and let them conquer every hill.
David worked on the road.cc tech team from 2012-2020. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes.