1x Drivetrains

Pros Cons
  • Simpler system, fewer parts, straightforward shifting.
    • Can be cheaper to build with old/used parts.
  • Narrow wide chainring locks in the chain to prevent drops.
  • Larger gaps between gears, fewer cadence options.
    • This is less of an issue as you increase gears in the cassette.
  • Wide chain angle is noisy and less efficient.
  • Backpedaling can drop the chain to smaller gears.
  • MTB cassettes are heavy, especially cheaper ones.

1x drivetrains don't need a left shifter or extra chainrings. They have some pros and cons to consider before switching.

 

 

1x12

Shimano doesn't have a 12 speed road group, and GRX is a 10 or 11 speed system. However, Deore, SLX, XT, and XTR are 12 speed mtb systems available today.

Shimano uses a new Micro Spline hub that allows a 10t smallest cog. This lets you run a smaller chainring in front for a more narrow chainline.

SunRace has a 12 speed cassette that fits on older freehubs. I'm currently using this one but be warned, it's 648g which is heavier than the Shimano options. An XTR 12 speed is 367g, but you will pay for that difference.