1X vs 2X Drivetrain Pros and Cons of Each

The Short Answer is:

When choosing between a 1x and 2x drivetrain, it depends on the type of rider you are and the terrain you will be riding the most. A 2x drivetrain gives you a wider range and makes it easier to tackle steep climbs, while a 1x drivetrain is much easier to operate and is less prone to chain drops. A 1x drivetrain is simpler to use, frees up space on your handlebars, and is less expensive than a 2x drivetrain. However, it has larger jumps between gears and less range compared to a 2x setup.

When it comes to choosing a drivetrain for your bike, one of the biggest decisions you’ll have to make is whether to go with a 1X or 2X setup.

A 1X drivetrain uses a single chainring at the front and a cassette with a range of gears at the back, while a 2X drivetrain uses two chainrings and a cassette with a narrower range of gears.

Both options have their pros and cons, and the choice ultimately depends on your riding style, terrain, and personal preferences.

In this article, we’ll take a closer look at the differences between 1X and 2X drivetrains and explore the advantages and disadvantages of each option. Let’s dive into the topic: 1X vs 2X Drivetrain

What Are 1X and 2X Drivetrains?

Drivetrains are the components of a bicycle that transmit power from the pedals to the wheels. The two main types of drivetrains are 1X and 2X. A 1X drivetrain has a single chainring at the front of the bike, while a 2X drivetrain has two chainrings.

A 2X drivetrain provides tighter gear ratios than a 1X drivetrain, which is preferable for road cycling because the change in gradients is more gradual than in an off-road setting, which typically varies between extremes in terms of terrain.

However, a 1X drivetrain eliminates duplicate gears, reducing the number of parts used and, by extension, parts to replace in the future. It also offers a slight weight saving, reduced maintenance, and improved chain retention.

Components of Drivetrains

The components of a drivetrain include the chain, cassette, chainrings, derailleurs, and shifters. The chain connects the pedals to the cassette, which is a set of gears on the rear wheel.

The chainrings are the gears on the front wheel that the chain wraps around. The derailleurs are the mechanisms that move the chain between gears, and the shifters control the derailleurs.

Gear Ratios and Range

Gear ratios refer to the relationship between the number of teeth on the chainring and cassette gears. A higher gear ratio means the bike is harder to pedal but can go faster, while a lower gear ratio means the bike is easier to pedal but can’t go as fast.

The gear range refers to the difference between the highest and lowest gear ratios available on a drivetrain. Most 1X drivetrains have a wide-range cassette to make up for the lost gears.

For example, SRAM Eagle boasts a 10-52 tooth cassette, and Shimano’s mountain bike groupsets have 10-51 cassettes. As a result, these 1X mountain bike drivetrains have a gear range of more than 500 percent, but this still isn’t as large a range as some 2X drivetrains.

2X drivetrains usually offer a wider gear range with a lower low or a higher high gear than 1X. A wider gear range allows you to efficiently ride a wider variety of terrain and inclines.

In addition, 2X usually offers smaller steps between gears, making it easier to maintain your pedaling rhythm while cycling at a high cadence. It’s important to choose the correct chainring size and cassette ratio to achieve the gear range you need for where you ride.

Research has shown that a 2X drivetrain is typically more efficient than a 1X drivetrain, with lower frictional losses in every gear. However, a 1X drivetrain can be a compelling proposition if you favor simplicity, a slight weight saving, reduced maintenance, and improved chain retention.

The 1X Drivetrain

The 1X drivetrain is a type of bicycle drivetrain that has become increasingly popular in recent years. It is characterized by having a single chainring at the front of the bike, and a cassette with a wide range of gears at the rear. This design offers several advantages over traditional multi-chainring drivetrains.

Simplicity and Fewer Gears

One of the main advantages of the 1X drivetrain is its simplicity. With only one chainring at the front, there are fewer components to worry about, which can make maintenance easier and less time-consuming.

Additionally, the lack of a front derailleur and shifter means that the cockpit of the bike is less cluttered, which can improve ergonomics and make it easier to access other controls.

Improved Chain Security

Another advantage of the 1X drivetrain is improved chain security. With a single chainring, there is less chance of the chain dropping off the front of the bike, which can be a common problem with multi-chainring drivetrains.

Additionally, many 1X drivetrains use a narrow-wide chainring design, which helps to keep the chain in place by providing more contact area between the chain and the chainring teeth.

Weight Savings

The 1X drivetrain can also offer weight savings over traditional multi-chainring drivetrains. With fewer components, the overall weight of the drivetrain can be reduced, which can be particularly beneficial for off-road and mountain bike applications where weight is an important consideration.

Off-Road and MTB Applications

The 1X drivetrain is particularly well-suited for off-road and mountain bike applications. The wide range of gears offered by the cassette at the rear of the bike means that riders can tackle steep climbs and technical descents with ease.

Additionally, the improved chain security offered by the 1X drivetrain can be particularly beneficial in off-road environments where the bike is subjected to more bumps and jolts.

The 1X drivetrain offers several advantages over traditional multi-chainring drivetrains, including simplicity, improved chain security, weight savings, and suitability for off-road and mountain bike applications.

The 2X Drivetrain

The 2X drivetrain is a type of bicycle drivetrain that has two chainrings in the front and a cassette with multiple sprockets in the rear. Here are some key features of the 2X drivetrain:

Wider Gear Range

Compared to a 1X drivetrain, a 2X drivetrain provides a wider gear range, which means that it can handle steeper climbs and faster descents. According to a lab test conducted by VeloNews, 2X drivetrains are more efficient across all gears than 1X drivetrains.

Smaller Gear Steps

A 2X drivetrain also has smaller gear steps than a 1X drivetrain, which means that the rider can find a gear that is more suited to their pedaling cadence.

This can be especially useful for road and touring applications, where the rider may need to maintain a consistent cadence over long distances.

Road and Touring Applications

The 2X drivetrain is well-suited for road and touring applications, where the rider may encounter a wide range of terrain and need a variety of gears to handle it.

The wider gear range and smaller gear steps of the 2X drivetrain make it easier to find the right gear for any situation.

Front Derailleur and Shifting

The 2X drivetrain requires a front derailleur to shift between the two chainrings. This can add some complexity to the shifting process, as the rider needs to shift both the front and rear derailleurs to change gears. However, with practice, shifting a 2X drivetrain can become second nature.

The 2X drivetrain is a versatile and efficient option for road and touring applications. It provides a wider gear range and smaller gear steps than a 1X drivetrain, which can make it easier to find the right gear for any situation.

While it does require a front derailleur and some practice to shift effectively, the benefits of the 2X drivetrain make it a popular choice for many riders.

Considerations for Choosing Between 1X and 2X

When choosing between a 1X and 2X drivetrain, there are several considerations to keep in mind:

Riding Style and Terrain

The best choice for you will depend on your riding requirements and the terrain you are riding on. If your riding sees you heading out on more technical gravel terrain and you’d prefer the benefits of simplicity and improved chain retention, then a 1x drivetrain may be a better choice.

1x drivetrains are best for riders who want to use their gravel bikes for off-roading, exploring, and having fun. They’re simpler, they’re better for rough terrain and technical riding, and they allow for wider tires.

On the other hand, 2x drivetrains provide tighter gear ratios than 1x drivetrains, which is preferable for road cycling because the change in gradients is more gradual than in an off-road setting, which typically varies between extremes in terms of terrain.

Gear Range Requirements

To get around the issue of limited gear range, most 1x drivetrains have massive rear cassettes. For example, SRAM Eagle boasts a 10-52 tooth cassette, and Shimano’s mountain bike groupsets have 10-51 cassettes.

As a result, these SRAM and Shimano 1x mountain bike drivetrains have a gear range of more than 500 percent, but this still isn’t as large a range as some 2x drivetrains. This means choosing the correct chainring size and cassette ratio to achieve the gear range you need for where you ride is key.

Weight and Efficiency

You’ll shed some weight, with a 1x set-up being on average 200-250 grams lighter than a 2x. In the case of 1x, simple also means reliable. Fewer parts, in theory, means there is less to go wrong.

However, the more extreme chain angles experienced when you are either in the smallest or largest gear lead to 1x drivetrains typically being less efficient than drivetrains with double chainrings.

1x drivetrains also tend to run the chain at higher speeds and higher tensions, which can also lead to greater friction and less efficiency.

Maintenance and Simplicity

1x drivetrains are quieter and more secure over rough terrain due to the tall, ‘narrow-wide’ chainring teeth and the clutch mechanism on the rear derailleur. For riders who are looking to take on really rough terrain, 1x is the better option.

1x drivetrains offer simplicity and improved chain retention, which can be beneficial for riders who prefer less fuss and maintenance. However, 2x drivetrains are generally simpler and more reliable on the road, and they provide a significant choice of gear ratios when paired with a 10, 11, or 12-speed cassette.

The choice between a 1X and 2X drivetrain depends on your riding style and terrain, gear range requirements, weight and efficiency, and maintenance and simplicity preferences.

Compatibility and Mounting

When considering the compatibility and mounting of 1X vs 2X drivetrains, there are a few key factors to keep in mind:

Frame Compatibility

One of the main differences between 1x and 2x drivetrains is their compatibility with different frame designs. 1x drivetrains allow for a more favorable frame geometry and more tire clearance than 2x drivetrains.

The reason is that 1x drivetrains allow bikes to have shorter chainstays because the chain line won’t interfere with the rear tire. 2x drivetrains, on the other hand, require longer chainstays so the chain doesn’t rub the tire when using the innermost chainring.

Mountain bikers generally prefer shorter chainstays because this design makes the bike more easily maneuverable.

Frame design can evolve with 1x drivetrains because they don’t require mounting points for the front derailleur and accommodate cranksets with multiple chainrings. Freed from accommodating derailleur mounts and chainrings, manufacturers can adjust seat tube design to increase tire clearance, frame stiffness, or compliance.

Front Derailleur Mounting

One of the main differences between 1x and 2x drivetrains is the front derailleur mounting. 2x drivetrains have two front chainrings and a close-range cassette, which requires a front derailleur to shift between the chainrings.

1x drivetrains, on the other hand, have a single chainring and a wide-range cassette, so there is no need to change gear on the front chainring. This means that 1x drivetrains are simpler to use, install, and maintain, and mechanically simpler because there are fewer parts to break or go wrong on a 1x setup.

With a 1x drivetrain, you can lose a chainring, the front derailleur, a cable and housing, and a shifter. This means fitting and indexing your gears is a far simpler job, and you’ve got fewer components to worry about when you’re out on the trails or servicing your bike.

However, 2x drivetrains provide tighter gear ratios than 1x drivetrains, which is preferable for road cycling because the change in gradients is more gradual than in an off-road setting, which typically varies between extremes in terms of terrain.

Some cyclists find that 2x drivetrains offer better performance than 1x drivetrains. With a 2x drivetrain, you may be able to maintain a higher average speed or ride further without tiring out.

The choice between a 1x and 2x drivetrain depends on the rider’s preferences and the type of riding they plan to do. 1x drivetrains are simpler, lighter, and offer more favorable frame geometry and tire clearance, while 2x drivetrains provide tighter gear ratios and better performance for road cycling.

Cost Comparison

There are several factors to consider when comparing the cost of 1X and 2X drivetrains. Here are some key points:

1. Cost: 1X drivetrains tend to cost less than equivalent 2X drivetrains because they have fewer components. For example, a Shimano GRX 810 1x groupset has a recommended retail price of £999, while the equivalent GRX 810 2x groupset is £1,049. An SRAM Red eTap AXS 2x groupset retails for £2,423 while opting for a 1x setup would decrease the price to £1,978.
2. Maintenance: 2X drivetrains have extra complexity with the maintenance of the front derailleur, additional gear shifter on handlebars, and a higher chance of chain drops. On the other hand, 1X drivetrains are much easier to operate and are less prone to chain drops.
3. Efficiency: A study found that the 2X drivetrain had lower frictional losses in every gear than the 1X system, with the caveat that the chainrings matched up with the ideal cogs in the rear. However, this efficiency can be impacted by a wide range of variables, such as aftermarket oversized pulley wheels, higher rear derailleur spring tension, chain efficiency, and chain lube.
4. Gear range: 2X drivetrains provide tighter gear ratios than 1X drivetrains, which is preferable for road cycling because the change in gradients is more gradual than in an off-road setting, which typically varies between extremes in terms of terrain. However, 1X drivetrains have a wider range of gears and make it easier to tackle steep climbs.

The cost of 1X and 2X drivetrains depends on several factors, including the number of components, maintenance, efficiency, and gear range.

While 1X drivetrains tend to cost less and are easier to operate, 2X drivetrains provide tighter gear ratios and better climbing performance. The choice between 1X and 2X drivetrains depends on the type of rider you are and the terrain you will be riding most.

Pros and Cons of 1X and 2X Drivetrains

When it comes to choosing between a 1X and 2X drivetrain, there are several pros and cons to consider.

Pros of 1X Drivetrains:

1. Simplicity: 1X drivetrains have fewer components, which means they are simpler to operate and maintain. There is no front derailleur, shifter, or front cable, and there is a single chainring, which makes shifting up and down faster and easier.
2. Better frame geometry and tire clearance: 1X drivetrains allow for a more favorable frame geometry and more tire clearance than 2X. This is because 1X drivetrains allow bikes to have shorter chainstays because the chain line won’t interfere with the rear tire.
3. Cleaner look: Many riders prefer the looks of a 1X drivetrain because it looks cleaner, simpler, and less complex. There is no front derailleur, shifter, or front cable, and there is a single chainring. Compared to a 2X bike, the system just looks a bit prettier and simpler.

Cons of 1X Drivetrains:

1. Larger jumps between gears: Often, 1X drivetrains have half the number of gears of 2X drivetrains, yet they still need to achieve the same gear range to help riders get over climbs and travel at speed. This means that there are larger jumps between gears, which can be less efficient and less comfortable for some riders.
2. Possibility of increased wear on certain components: With a 1X drivetrain, the chain has to work harder to cover the same range of gears, which can lead to increased wear on certain components, such as the chain and cassette.
3. Complications around freehub standards: 1X drivetrains require a cassette with a larger range of gears, which can lead to complications around freehub standards. Some freehubs may not be compatible with certain cassettes, which can limit your options when it comes to upgrading or replacing components.

Pros of 2X Drivetrains:

1. Better gear range and smoother gear transitions: Because 2X drivetrains have more gears, more gear range, and less friction, you can maintain a higher average speed and ride further without tiring out. They also have smaller gaps between the gears, which means that you can fine-tune your cadence and keep pedaling at a comfortable RPM no matter what speed you’re riding at. Changing between gears gives less of a jump, so you won’t interrupt your flow when you switch between gears.
2. Tried and true technology: 2X drivetrains have been on the market for many decades and are a tried and true technology. They are an excellent choice for those who ride a wide range of surfaces and grades, and road riders also prefer 2X drivetrains.

Cons of 2X Drivetrains:

1. Heavier: 2X drivetrains require a front derailleur, second chainring, and front shifter, which add weight to the bike. This can make the bike less maneuverable and less efficient, especially on steep climbs.
2. Require longer chainstays: 2X drivetrains require longer chainstays so the chain doesn’t rub the tire when using the innermost chainring. This design makes the bike less maneuverable, which can be a disadvantage for mountain bikers who generally prefer shorter chainstays.

The choice between a 1X and 2X drivetrain comes down to personal preference and riding style. 1X drivetrains are a good choice for those who prioritize simplicity, better frame geometry, and a cleaner look.

2X drivetrains are an excellent choice for those who ride a wide range of surfaces and grades and prioritize better gear range and smoother gear transitions.

Conclusion on 1X vs 2X Drivetrain

In conclusion, the choice between a 1X and 2X drivetrain depends on the type of rider you are and the terrain you will be riding most. A 2X drivetrain gives you a wider range and makes it easier to tackle steep climbs, while the 1X is much easier to operate and is less prone to chain drops.

The 1X drivetrain lets you focus on your ride, instead of constantly adjusting gears and is more aerodynamic. However, it has less range and there is a noticeable drop between gears, meaning you might not be able to find the right gear every time.

On the other hand, a 2X drivetrain allows you to maintain a straighter chain line, which reduces chain wear and frictional losses. It also has closer ratios, which is beneficial for riding on flatter terrain.

The 2X drivetrain is typically more efficient than a 1X drivetrain, but this efficiency can be impacted by a wide range of variables. Ultimately, the choice between a 1X and 2X drivetrain comes down to personal preference, the sort of riding you want to do, and the type of terrain you intend to tackle.