Upgrading your drivetrain to a 1 × system is an innovative and easy way to drop weight, reduce the chance of mechanicals and create a clean, efficient drivetrain. You may have noticed that when riding a 3 x 9 or 3 x 10 equipped bike you find you are in the middle ring much of the time or in the larger ring on a 2 x setup. Removing the extra chainring(s) could be just the change you are looking for in your machine!
Mountain bike drivetrains have gone from 3 x 9 to 2 x 10 and now 1 x 10, 1 x 11, 1 x 12 removing duplicate gear ratios, weight and running costs while increasing efficiency and reliability.
A number of innovations have made reliable 1 x drivetrains possible: Narrow Wide chainrings hold the chain so well that you don’t require a chain guide in place of the front derailleur. 2 x 10 drivetrains led to the creation of larger range cassettes with 11-36t ratios to compensate for the loss of the granny gear. This also means that you have a far larger range of gears available than previously, perfect for 1 x. The clutch type rear derailleur means 1 x drivetrains are very unlikely to drop a chain, even in extreme riding environments. Finally, range extender rear cogs with 40 to 52 teeth provide a bail out gear ratio similar to the granny gear that the original 3 x systems provided.
