Is the power2max power meter compatible with Shimano Ultegra 8100 and DURA-ACE 9200 chainrings?

Yes, all power2max 4-bolt power meters are compatible with Shimano Ultegra 8100 chainrings and Shimano DURA-ACE 9200 chainrings.

Since Shimano road cranksets use an integrated spider (the drive-side crank arm and spider portion of the crankset are one solid piece), you cannot install a spider-based power meter directly on the crankset. Therefore, power2max makes this power meter specifically for Shimano users: power2max ROTOR ALDHU Road Power Meter Crankset

This power2max power meter comes on a ROTOR ALDHU crankset. In addition to being a great all-around power meter, here’s why it’s great for Shimano users:

1) If you select one of the 24MM ALDHU Crank sizes, this power meter will come with the same spindle size as your current Shimano crankset and will fit your bottom bracket without any changes. This makes installation a breeze.

2) If you select the 110 4-Bolt Shimano BCD option, you can also use your current Shimano chainrings on it.