Help with SCP and Atari 400/800 disks

[Larry44]

There is no such thing as RPM with flux data.  You can read or write the disk using different speed drives and the end result will be correct.

Stepping is a completely different matter.  You seem to believe that there is no "chatter" when reading, but you believe there is when writing?

Near silence when reading (just the quiet noise of the head stepping); Bang, Bang Bang... when writing starting at track 20.  No mistaking the sound -- plenty loud.