At Redchilli Bikes, we believe gravel gearing should be chosen for the rider and the terrain — not simply accepted as part of a standard specification.
Chainring size, cassette range and ratio spacing can completely change how a gravel bike feels on steep climbs, rough surfaces, long road links and loaded rides. That is why gearing is considered as part of the complete build. Because the right gravel bike should not force the rider to adapt to the drivetrain. The drivetrain should support the way the rider actually rides.
A gravel bike can be beautifully fitted, responsive and comfortable, yet still feel wrong if the gearing does not suit the ground beneath it. Knowing how to choose gravel gearing begins with an honest view of your riding: not the occasional fast group ride or one ambitious event, but the gradients, surfaces, distances and loads you meet most often.
For British gravel riders, that can mean a quick road link, broken lanes, loose forestry tracks, wet bridleways and a steep climb that arrives after four hours in the saddle. One fixed drivetrain specification rarely serves all of that equally well. The right choice is the one that lets you hold a natural cadence, preserve your legs and stay in control when the ride gets properly difficult.
Start with the ride, not the number of gears
It is easy to compare a drivetrain by counting sprockets or looking at the largest cassette cog. Those details matter, but they do not tell the whole story. Gearing is a relationship between the chainring at the front, the cassette at the rear and the rolling circumference of your tyre.
Begin by considering where and how you ride. A rider using their gravel bike for fast all-day loops on Dartmoor lanes will usually value a higher top gear and closely spaced ratios. Someone riding technical trails, long forest climbs or loaded bikepacking routes may benefit more from a lower climbing gear, even if that creates larger gaps between some ratios.
Your fitness matters too, although it should not be used to justify an unnecessarily hard bottom gear. A strong rider can force a larger gear over a short climb. On a long day, in mud, with tired legs or luggage on the bike, that same gear can turn a manageable ascent into a grinding effort that compromises the rest of the ride.
A useful question is simple: when the surface turns loose and the gradient reaches double figures, do you want to keep turning the pedals smoothly, or are you content to push and walk? There is no pride in choosing gearing that looks race-ready on paper but prevents you from riding the terrain you set out to enjoy. A useful gravel setup should make the hardest parts of the ride more manageable without compromising the riding you do most often.
Understand range, ratios and cadence
Gear range is the difference between your easiest and hardest gears. It determines whether the bike can cover steep climbs as well as fast descents and road sections. Ratio spacing is the jump from one gear to the next. It determines how easily you can find a comfortable cadence.
A wide-range cassette gives more climbing assistance, but the jumps between sprockets can be more noticeable. A narrower cassette keeps changes more closely stacked, which feels particularly refined when maintaining pace into a headwind or riding with a group on the road. Neither is inherently better. The priority depends on whether your riding asks more of low-speed control or high-speed consistency. This is one reason gearing should be considered alongside tyre size, wheel choice and terrain rather than viewed in isolation.
Cadence is personal, but most riders are more efficient and more comfortable when they can spin rather than repeatedly labour at very low revs. On gravel, keeping a little momentum through changing surfaces often helps traction too. If you are mashing a big gear uphill, the rear wheel is more likely to break traction and your upper body will work harder to keep the bike moving forward.
It can help to think in metres of development: how far the bike travels for one full turn of the pedals. With a typical 700c gravel tyre, a 40-tooth chainring paired with a 44-tooth sprocket gives roughly two metres of development. That is a sensible low gear for many unladen rides, but it may still be demanding on sustained, rough climbs. Pair the same chainring with a 51-tooth sprocket and the low gear falls closer to 1.7 metres, offering more room to spin.
At the other end, a 40-tooth chainring with a 10-tooth sprocket provides about 8.8 metres of development. For many gravel riders, that is ample. If your regular rides include fast road descents, chain-gang pace or you simply prefer not to spin out, a larger chainring or a two-chainring system may be more appropriate.
How to choose gravel gearing: 1x or 2x?
The choice between one chainring and two shapes the character of the whole bike.
A 1x drivetrain uses a single front chainring. Its appeal is clarity: one shifter controls every gear, the chainline is straightforward, and the system generally copes well with the mud, vibration and imperfect conditions that gravel riding brings. It also leaves more scope for a wide cassette, making it a strong choice for technical routes and riders who value a very low climbing gear.
The trade-off is spacing. To achieve a broad range with one chainring, the cassette usually needs bigger steps between sprockets. That may be barely noticeable on mixed-surface adventures, but riders who spend meaningful time at a steady pace on tarmac can find it harder to settle into their preferred cadence.
A 2x drivetrain uses two chainrings and a front derailleur. It can provide a similarly broad overall range while retaining closer cassette ratios. This suits riders whose gravel bike doubles as an endurance road bike, those who ride fast mixed-surface events, or anyone who values smooth cadence changes over rolling terrain.
It does add a front shift and a little more mechanical complexity. In very muddy, remote or rough conditions, some riders prefer the simplicity of 1x. Yet a well-set-up 2x system is far from fragile, and its closer ratios can make a long road transfer feel notably more composed.
There is no universal answer. The better choice is the system that gives the rider the usable range they need without adding unnecessary compromise. A 1x setup is often the more purposeful choice for steep, technical gravel and bikepacking. A 2x setup can be the more versatile choice for riders whose definition of gravel includes a substantial amount of quick road riding.
Choose the lowest gear first
Most gearing mistakes start at the top end. For many riders, having one genuinely usable low gear is far more valuable than carrying extra top-end gearing they rarely use. Riders worry about running out of gear on a descent, then discover their bike is over-geared for the climbs they ride every weekend.
Set your lowest gear according to the hardest terrain you intend to ride under realistic conditions. Consider wet roots, loose stones, fatigue, winter clothing, a loaded saddlebag and the fact that a 15 per cent climb feels very different after 100 kilometres. For many UK riders, a low gear around two metres of development is a useful starting point. If your routes regularly include very steep, unmade climbs or loaded touring, lower than that is often sensible.
A compact 2x combination such as 46/30 with an 11-36 cassette gives a low gear of roughly 1.8 metres and a high gear above nine metres. It offers considerable range with close enough ratios for road use. A 1x setup with a 40-tooth chainring and 10-51 cassette reaches a similar low gear, with a slightly lower top end and wider cassette steps.
These are not prescriptions. Tyre size, wheel size, drivetrain compatibility and your preferred cadence all affect the final answer. They do show why the chainring and cassette must be chosen together rather than as isolated upgrades.
Then protect the top end you genuinely use
Once the climbing gear is right, consider your realistic maximum speed. If you are coasting on most descents above 50 km/h, there is little benefit in specifying a huge top gear simply to keep pedalling for another few seconds. Gravel tyres, surface quality, corners and traffic often limit safe speed before gearing does.
However, a rider using their gravel bike for fast sportive-style rides may regularly need to pedal on descents and through high-speed road sections. In that case, a 42- or 44-tooth 1x chainring, or a 2x system, may feel more appropriate than a 38- or 40-tooth option.
Changing the front chainring is often the simplest way to tune a 1x bike. Going from 40 to 38 teeth makes every gear easier by five per cent, while moving to 42 teeth makes every gear harder by the same amount. Small changes can have a meaningful effect on the ride, particularly if the existing setup is almost right. This is where a tailored build can make a surprisingly large difference, because the drivetrain can be tuned around the rider rather than inherited from a fixed factory specification.
Avoid gearing decisions based on one event
A race in the Peaks, a holiday in the Alps or a heavily loaded bikepacking trip may require a different setup from your normal riding. That does not necessarily mean your everyday bike needs to be built around the most extreme day on the calendar.
Where compatibility allows, it can be more useful to plan for adjustable gearing: an alternative chainring for a key event, or a second cassette and chain to suit a specific season or route. The best long-term specification is one that serves the majority of your riding without creating compromises every time you leave home.
This is also where a personal build process earns its value. At Redchilli, gearing is considered alongside wheel choice, tyre volume, riding position and intended terrain, because each decision affects how the bike feels when it is working hard. A low gear that is perfect on paper may be less useful if the overall build is not designed around the rider and their real routes. A low gear that looks perfect on paper is only truly useful when the rest of the bike is also designed around the rider, their terrain and the way they actually ride.
Test the feeling, not just the figures
Numbers make a useful starting point, but they cannot fully describe the experience of a drivetrain. Notice the gear you reach for on your hardest regular climb. Pay attention to whether you are spinning excessively on the road, hunting between two sprockets, or avoiding certain routes because the gearing makes them less enjoyable.
Your ideal gravel gearing should disappear beneath you. It should give you a calm, usable climbing gear when traction is limited, enough pace for the roads between the trails, and ratios that make sense for the way you naturally pedal. Choose it for the riding you want to repeat, and the bike will feel more capable every time the route becomes uncertain.
The right gearing starts with the terrain
Gravel gearing is not about choosing the biggest cassette or the most fashionable drivetrain. It is about creating a usable range that matches the climbs, surfaces, distances and conditions the rider actually encounters.
At Redchilli Bikes, gearing is considered as part of the complete bike — alongside fit, wheels, tyres and intended use. Because the best drivetrain is not the one with the most impressive numbers. It is the one that helps you keep riding when the road — or trail — gets harder.
Redchilli Bikes. Built around you. Built around the ride ahead. Your Bike. Your Way.