Over the past few seasons, the single chainring – long reserved for mountain biking and gravel riding – has made its way onto the tarmac. This configuration, often referred to by the English term ‘1x drivetrain’, is attracting attention for its simplicity, its sleek aesthetics and the promise of reliability it offers. But behind the minimalist appearance lies a genuine engineering choice, with its own advantages, limitations and practical implications.
The idea of removing the front derailleur and one of the chainrings from a road bike crankset may seem radical. However, with the rise of 12- and 13-speed drivetrains and wide-range cassettes, this solution is now technically viable, even in competitive settings. It was even spotted on certain stages of the 2025 Tour de France, and not just on flat sections: some riders dared to use it in the mountains, proof that advances in equipment are pushing back against traditional limitations.
What is a single chainring? A simplified system
The principle is simple: a single chainring at the front – usually with between 42 and 48 teeth, depending on the terrain and the rider’s power output – and a rear cassette offering a wide gear range. The absence of a front derailleur frees the rider from a number of mechanical and mental constraints. Gear changes are made solely at the rear, making the shifting process more intuitive: one lever to increase the gear ratio, one lever to decrease it, and nothing else to think about. This simplicity appeals to both competitive cyclists and recreational cyclists alike, particularly over long distances where concentration is vital.
This streamlined design also reduces potential sources of problems. Changing chainrings, particularly on the road, is a moment when the chain is under significant tension and must bridge a large difference in diameter, which increases the risk of the chain hesitating or derailing. Removing this operation eliminates this weakness. Modern chainrings, featuring narrow-wide profiles (alternating thin and thick teeth), keep the chain in place even on rough surfaces, whilst clutch derailleurs provide constant tension that reduces chain flutter.
Why choose a single chainring for road cycling?
Mechanical simplicity
The main advantage of a 1x setup is the reduction in the number of controls:
- Just one lever to operate
- Fewer reflexes needed to avoid chain crossings
- Fewer adjustments and less maintenance (goodbye to the front derailleur and its sometimes finicky adjustments)
For amateur cyclists, this simplicity translates into smoother gear changes and fewer distractions.
Greater reliability
Chainring changes are mechanically more demanding:
- Significant difference in diameter between the small and large chainrings
- The chain crosses over at the top of its stroke, under maximum
tension By eliminating this step, the risk of the chain jumping or irregular shifting is reduced.
Narrow-wide chainrings and modern derailleur cogs ensure virtually perfect chain retention, even on rough roads or cobblestones.
Weight and aerodynamics
By removing the front derailleur, a chainring and sometimes the associated cable and actuator, you can save between 120 and 250 g on a top-of-the-range bike.
In terms of aerodynamics, the gain is modest but real: a few watts at high speed. In a time trial or criterium, that’s always worth taking.
The gear range: the real issue
The historical argument against single-chainring set-ups on road bikes centred on the gear range. With a double chainring, it is possible to have an ultra-short gear for climbs and a very long gear for sprints, whilst maintaining small gaps between the gears. Modern cassettes have reduced this gap: a 48-tooth chainring paired with a 10–46 cassette offers a range of 460 per cent, which is close to the 494 per cent of a 48/35 setup with a 10–36 cassette. In other words, whether climbing or descending, the difference is minimal.
The weak point remains the gear spacing. Covering the entire range with a single chainring means having to accept larger gaps between gears. For a cyclist who values a consistent cadence, this can be frustrating, particularly on undulating terrain where one quickly alternates between moderate effort and bursts of speed. However, increasing the number of gears mitigates this effect: with 13 gears, the gap becomes acceptable for most cyclists, and some eventually stop noticing it after a few rides.
Optimising your single-platter setup for touring
Choosing your chainring
- 44 teeth: for mountain riding
- 46 teeth: all-round use
- 48 teeth and : flat terrain and high speed
Always opt for the narrow-wide profile.
Cassette
- 10–36: hilly roads, competitive riders
- 10-44: endurance, cyclosportives with mountain passes
- 10-46: gravel and extreme versatility
Derailleur
- Long cage for large sprocket
- Chain retention system to stabilise the chain
A choice based on profile and riding style
It is clear that the single chainring setup is not suitable for all cyclists. On long mountain stages where versatility is essential, a double chainring still has the edge. On the other hand, for a criterium, a triathlon or a ride on relatively even terrain, the simplicity of the 1x setup means fewer adjustments, fewer risks and more direct handling. For a cycle commuter or a cyclist who alternates between road and trails, it also guarantees a robust drivetrain requiring less maintenance.
Aesthetics also play a part. Many feel that a road bike without a front derailleur and with a perfectly straight chainline has a modern, aggressive look. And in a world where image matters almost as much as performance, this is a significant consideration.
A trend that’s gaining ground
The fact that professional cyclists have used a 1x drivetrain on stages of the Tour de France, including in the mountains, marks a shift. It should be borne in mind, however, that these athletes have far greater power output than most amateurs and benefit from technical support during races. What works for them may not necessarily work for a cyclist tackling long routes alone without assistance.
In reality, choosing between 1x and 2x is less about determining which is “better” and more about deciding which best suits your needs. The double chainring remains the ultimate all-round solution, but the single chainring is now a fully-fledged alternative, capable of offering a smoother, lighter and often more enjoyable riding experience.
In summary:
Principle: a single front chainring (38 to 54 teeth) and a wide-range cassette; no front derailleur.
Main advantages:
- Ease of use and maintenance.
- Lower risk of derailment thanks to narrow-wide chainrings and clutch-type derailleurs.
- Clean, streamlined look and a slight aerodynamic advantage.
- Allows for stiffer frames with greater tyre clearance.
Weight: may be lighter than a double chainring setup, but this depends on the choice of components (wider cassettes are heavier).
Gear range: now similar to a double chainring setup with 12- or 13-speed drivetrains, but with larger gaps between gears.
Disadvantages:
- Less fine-grained gear spacing, more pronounced variations in cadence.
- Less versatile for very varied terrain or long climbs.
Who is it for?
- Criteriums, triathlons, rides on even terrain.
- Commuting or mixed road/gravel riding.
- Cyclists looking for a minimalist and reliable bike.
Market:
- SRAM: market leader with a comprehensive range for 1x road setups.
- Shimano: limited options, adaptations via GRX.
- Campagnolo: the high-performance Super Record 13.
Trend: occasionally adopted by professionals, even in the mountains, but the choice should be based on intended use rather than simply following the trend.
FAQ – Single-chainring road bike
Is a single chainring suitable for mountain riding?
Yes, if you choose the right gear ratio (for example, a 46-tooth chainring with a 10–46 cassette). This will give you the same gear ratio (1:1) as with a small 34-tooth chainring and an 11-34 cassette. However, a double chainring remains more versatile, offering finer gear spacing for long climbs.
Do I lose top speed with a 1x setup?
Not necessarily. A 50/34 double chainring with an 11-34 cassette will have a maximum gear ratio of 9.71m (50×11), which is equivalent to a 46×10 setup that produces 9.82m per pedal revolution. With a 46-tooth single chainring and a cassette starting at 10 teeth, you can ride at speeds comparable to those of a double chainring setup.
Does a single chainring save weight?
In most cases, yes, but the benefit may be reduced by the weight of wide cassettes and long-cage derailleurs.
Does this cause the chain to wear out more quickly?
Wear is comparable to that of a double chainring if the drivetrain is well maintained. The chainline is optimised, but the wide-range cassette may place greater strain on the extreme gears.
Can a single chainring be fitted to any road bike?
You need to check the compatibility of the crankset, the rear derailleur (UDH or otherwise) and the cassette (11, 12 or 13-speed).
Why don’t all pros ride 1x?
Because on certain stages, particularly hilly or mountainous ones, a double chainring offers a more consistent gear range and greater versatility. The choice depends on the route profile and your strategy.
Is a single chainring suitable for cycle commuting or bikepacking?
Yes, it’s actually an excellent option for daily commutes: fewer parts, less maintenance, and simpler, more reliable gear changes.
