The smallest chainring that will fit on a power2max MTB power meter is a 32T round chainring or a 34T oval. This is because if the chainring is smaller than this, the diameter of the chainring would be smaller than that of the power2max power meter, and you would not be able to mount the chain on the chainring properly. The one exception to this is the Garbaruk 1x 104 BCD 30T MTB Chainring which is specifically designed to fit a power2max power meter. Please note, in order to get around the issue described above (diameter of the ring being too small), this chainring is made with a 1 mm offset, which therefore allows it to work. This means your chainline will move 1 mm inboard. This shouldn’t have a noticeable impact on the operation of your drivetrain but it’s worth making note of.
April 27, 2021