1X DRIVETRAINS – BUYERS GUIDE

Shaun George BOTS Guides

A trend that’s more recent in the world of cycling is the simple, yet confusing 1x (pronounced as “one-by”) drivetrain. Many riders over the past few years have been preferring the 1x drivetrains over the now more traditional 2x, and 3x setups. It’s also been noticed that many manufacturers are now equipping their high-end bikes with 1x drivetrains – this means they’re better, right?

Shimano’s new GRX gravel 1x groupset

Arguably one of the most important parts of a bike these days is its drivetrain. The humble drivetrain has seen countless configurations and standards come and go and come back again. From single speed all the way up to 13-speed, it seems that each new iteration of a bicycle’s drivetrain just keeps adding new gears to make climbs easier and descents faster.

Then why are so many riders these days ditching their front derailleurs and switching to a 1x setup? advantages like easier gear changing, less weight, and more room for other essential bike upgrades on your handlebars are some of the reasons. Let’s first truly understand what a 1x drivetrain is.

WHAT IS A 1X DRIVETRAIN?

A 1x or one-by drivetrain refers to a setup with a single chainring up front and any number of gears on the cassette. The most commonly seen today are 1×10, 1×11 and 1×12.

Previously, if riders wanted a drivetrain that was simpler than a 2x or 3x, yet more versatile than a single speed, they had to resort to a cobbled together solutions with lackluster reliability. More often than not, chains would drop, gears would mis-shift, and the ideal gear range simply wasn’t there.

Luckily, with the advent of technological innovations, 1x drivetrains are now more attainable and easier to set up than before. Unfortunately, technology wasn’t up to the task to sufficiently replace the gear deficit of the loss of a few chainrings. It’s close, but not quite close enough for some.

Simplicity and low weight are the two main reasons for this trend. They’re both really good advantages to have on your bike when your intent is to either have fun or race professionally.

HOW DOES IT WORK?

Credits – Bike Exchange

You need mainly three features for your 1x drivetrain to work successfully:

  1. Narrow/Wide Chainring
  2. Wide-range Cassettes
  3. Clutch Rear Derailleur

1. Narrow/Wide Chainring

One of the biggest issues facing “budget” and DIY 1x setups of the past was dropped chains. Caused by a buildup of mud or debris on the chainring. Dropped chains were once a regular occurrence while shifting, sprinting, or taking sharp turns. 

Nowadays, most 1x drivetrains use what’s called a wide/narrow chainring tooth profile. These chainrings mirror a chain’s inner and outer links and guide the bouncing chain to mesh with the chainring’s teeth as it falls into position. This provides a secure fit and prevents dropped chains even over the roughest of terrains.

Each brand has it’s own little variations and names for their narrow/wide chain offerings but they are essentially the same thing.

2. Wide-range Cassettes

Thanks to the 1x drivetrains, gearing ranges have reduced slightly. That, however, hasn’t stopped drivetrain manufacturers such as SRAM from working around that loophole.

Modern 1x drivetrains, along with SRAM’s XD driver body – that has been expanded greatly, cassettes are now commonly available with 9 and 10 tooth high cogs and low cogs in the 40 and 50s. This range provides most riders with all they need on the trails.

The wide gear ranges have virtually eliminated the need for multiple chainrings up front, as nearly the same gearing can be achieved by going 1x.

3. Clutch Rear Derailleur

While initially expensive and only available at the top end, clutched derailleur technology has trickled down to lower price points (SRAM NX; Shimano Deore) making it much more affordable for all riders.

Shimano’s Ultegra RX800

Both major drivetrain manufacturers – SRAM and Shimano offer clutch rear derailleurs, meaning you can experience virtually no chain slap regardless of which brand you prefer. In fact, clutch technology has proven so beneficial to performance on mountain bikes that SRAM and Shimano utilize it in its endurance road and cyclocross drivetrains as well.

WHO IS IT FOR?

Every rider is different. Some rely more on technique, some on efficiency, some on strength, and so on…

The average rider needs to account all of these things in order to choose a bike that will not only fit their style and capabilities but allow them to have the most fun they can have on a bike.

The simplicity of a 1x drivetrain doesn’t seem important at first, unless you start to see the advantages it brings to your riding. There’s less that can go wrong out on a ride. Your shifts will be smoother, easier, and more reliable each and every time. Even your chain getting stuck or dropping down by not shifting on time or shifting poorly on technical parts won’t happen. All of this actually happens a lot when you are focusing on what’s in front of you.

Even the weight factor plays a big role when considering the simple 1x drivetrain. The less weight your bike has, the more control you will have over it. It is that simple.

Besides all of this, your left hand will be completely free to focus on steering control, braking, and maybe using the dropper seatpost (if you have one).


1x drivetrains are great but that doesn’t mean that you simply follow the trend because it has caught on. The reality is there is no “perfect” drivetrain. We’ve seen people prefer cheaper 2x and 3x drivetrains over much better 1x setups – it’s a personal preference that you can only properly judge after using it.

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