New Shimano Di2 Dura-Ace R9200 & Ultegra R8100

I agree with this, I’d only add that not all NW rings are created equal.

  • Tooth profile
  • Tooth height
  • Chain compatibility (which is a function of the above two)
  • Offset to chainline

Can all dictate how tightly a chain is held (and therefore wear rates, noise).

My Garbaruk GRX 1x ring claims to support Shimano HG+ and SRAM Flat Top chains as well as all other generic 12 speed chains. This probably means a compromise in design, I am running a Shimano 12 speed SLX (aka: 105) level chain and the fit is noticeably looser than an 11 speed chain on the Shimano GRX narrow/wide ring.

Having said that my Garbaruk has been absolutely flawless on a flat-bar bike with an XT M8000 drivetrain (without the clutch engaged). Never dropped a chain, ever and I ride a lot of gravel and crappy singletrack on that bike.

Supplementary note: I also think drivetrain efficiency is not as simple as 2x vs 1x (as many make it out to be). A slightly loose chain on a NW ring is likely to be way more efficient than a really tightly held chain on a NW ring, because the chainline can vary by 1-2mm either side. That can make a huge difference to efficiency as well. This is probably an area worth a bit of scientific investigation and testing from the usual suspects (Hambini, Peak Torque, ZFC)