This post compares the advantages and disadvantages of 1×12 and 2×10 drivetrains.
The Advantages of 1×12 Drivetrains
- Simplicity & Elegance
Two of the main incentives to go for a 1x drivetrain are its aesthetics (clean look) and simplicity.
A 1x drivetrain such as 1×12 does not require a front derailleur or a front shifter. Consequently, the drivetrain acquires a simple and elegant silhouette.
- Lighter weight
A 1×12 drivetrain has the potential to be lighter because it requires fewer parts (one chainring, no front derailleur, no front shifter). However, this doesn’t always happen in practice because a 1×12 drivetrain demands a larger cassette to give the user usable gearing.
Also, the weight of the components varies according to the material and the production quality.
- High-end Parts
Currently, the MTB world is focused on 1x drivetrains. As a result, the user can find a lot of high-end components in that segment implementing the latest technologies. Meanwhile, 2x drivetrains such as a 2×10 are considered mid-range.
- No Redundant Gears
1×12 eliminates gears that are close enough to each other to be considered redundant.
The Disadvantages of 1×12 Drivetrains
- Limited Gearing
The main issue with a 1×12 drivetrain would be the limited number of gears due to the absence of a second or third chainring. To compensate for the lack of chainrings, 1×12 drivetrains are combined with wide-range cassettes that have a massive first gear (e.g., 42T + cog).
Similar cassettes weigh a lot and require a derailleur with a very long cage. Otherwise, the derailleur will fail to get on the largest cog.
It may be surprising to some, but on average a 1x drivetrain will cost more if the user relies on high-end components.
A 1x drivetrain uses fewer parts than 2x and 3x, but the cassette and the rear derailleur increase the price tag significantly.
The derailleur has a massive range and needs to be robust enough to keep the chain tension as stable as possible (otherwise the chain might drop and cause an accident due to the absence of a front derailleur guiding it).
The other expensive part would be the cassette. It costs more due to the extra large cogs and the low production volume. 1x drivetrains are found only on mid and higher-end bikes. Thus, the production process is not nearly as large as that of 2x and 3x drivetrains. The rarer a product is, the more it costs because it’s considered premium.
And the final reason for the high price would be the components’ class. You cannot have a 2-3k dollar bike and install the most basic cassette and derailleur on it.
Consequently, manufacturers invest a lot in the production of high-quality 1x drivetrain parts that match the rest of the bike.
A 1×12 setup results in a phenomenon known as cross-chaining because the chain has a single pivoting point at the front. When pedaling in the smallest or largest gear, the chain is crooked when looking at it from above.
Cross-chaining is not the end of the world, but it does make pedaling slightly less efficient (at least in theory) and stresses the chain more.
The Advantages of 2×10
- Massive Gear Range
A 2×10 setup can offer you all the gears you will ever need. Meanwhile, a 1×12 will always feel a bit like a compromise when it comes down to range.
For example, if the chainrings are 26 and 36 (a common choice) and are coupled with an 11-42 cassette, a 1×12 drivetrain can never offer you the same spectrum of gears.
When comparing gearing, it’s useful to become familiar with the term gear ratio. The gear ratio indicates the number of rotations that the rear wheel and respectively the rear cog make per 1 full revolution of the cranks. To determine, the gear ratio one needs to know the number of teeth on the chainring and the cog in use.
A high gear ratio gives more top speed because each revolution of the cranks triggers more spins of the rear wheel and results in a greater travel distance.
A low gear ratio makes climbing easier because each spin of the cranks requires fewer rotations of the rear wheel.
A 26/36 crankset + 11-42 cassette gives us a 0.6 low gear ratio (26/42) and а 3.7 high gear ratio (36/11).
If you want to get a similar gearing with a 1×12 setup, you will need an expensive wide-range cassette.
For example, if you use a 34T chainring and a massive 10-52 cassette, you will get a 0.65 low gear ratio (34/52) and a 3.4 (34/10) high gear ratio.
In both cases, the gearing is quite close, but the 1x drivetrain setup does not fully match the range of 2×10 and costs a lot more. (A 10-52 cassette could be over USD 200 if made by a reputable brand.)
- Smaller Jumps Between The Gears
The second chainring makes it possible to use shorter-range cassettes that in return offer smaller jumps between the gears.
For example, a typical 10-speed 11-42 cassette has the following gradation – 11-13-15-18-21-24-28-32-36-42.
Meanwhile, a 12-speed 10-52 cassette has the following cogs – 10-12-14-16-18-21-24-28-32-36-42-52.
The largest jump on the 11-42 cassette is 6 teeth whereas that of the 10-52 is 10 teeth. The jumps in the middle of the 10-52 cassette are massive too (e.g., 21 to 24 and 25 to 32).
The larger jumps between the gears make it more difficult to maintain a smooth cadence (rotations of the cranks per minute). A high cadence such as 90 RPM is known to result in a more efficient output and higher average speeds.
It’s also worth mentioning that you can go for 2×11 or 12 instead of 2×10 and get even smaller jumps between the gears.
The Downsides of 2×10
- More Complicated
2×10 requires the rider to operate a front shifter and a front derailleur. The manipulations are not terribly difficult, but they do complicate the shifting process and some prefer to skip them.
- Not as Slick Looking
A 2×10 drivetrain is not as clean as a 1×12. Those after aesthetics may consider this point crucial.
- Extra Weight
When all parameters are equal, a 2×10 will weigh a bit more. The extra weight isn’t detrimental, however, because it’s too little to matter and positioned in the middle of the bike where it has a smaller negative impact.
Summary: What You Need To Know
- 2×10 offers an exceptional gear range that would satisfy the needs of most riders.
- 2×10 is cheaper and is therefore a more practical choice for people who can’t afford the latest components.
- 2×10 is better for hybrids because it can offer you a greater top speed and a massive low gear.
- 1×12 is simpler to use and maintain. It is also more aesthetically pleasing.
- 1×12 is more expensive even though it uses fewer parts due to the lower demand and the higher class of components.
- 1×12 tends to be lighter, but the weight savings are not game-changing.
What to choose?
Drivetrains are not the most important part of an MTB. The frame, suspension, and wheelset play a bigger role.
Therefore, it makes no sense to invest the extra money into 1×12 if other parts of the bicycle are lacking. In that case, it’s wiser to save the money and go with 2×10.
If you have the funds and consider the ease of use that 1×12 offers important, it would be logical to go for it.