questions in the title thanks guys ;D
The first run has a hex-nut style axle, and only came with a pad response option. The second run has a round nut axle setup, and you have the option of choosing flow-groove or pad response.
k cool thanks ;D
The 2nd run M1 pad response groove is shallower so you can’t put Silicone in it. (thats why you get the flow groove one lol) The 1st run M1 could have silicone put in it because the groove wasn’t too shallow.
I believe the response groove was not changed from the first to the second run. The thick One Drop pads sit flush in both from what I’ve heard. You can easily silicone a second run M1. They changed the hex-nut to a circle nut, only because it was easier to assemble.