That ripple is coming from the fact that the whole system is springs including the belt tags. When you apply gravity (or rather hit play) if you watch closely you will see the whole thing drop a bit and that gets the springs vibrating. With no “force” to stop them they will continue forever.
<div>You have some unusual settings in the Tag tab and I assume those are to try and stop the ripples. Try bringing your iterations down to 2 or upwards of 10 (top of the list). There will be an initial settle but then things should get smooth and stop.</div><div>
The system is letting the flag drop right at the start (and you could animate the gravity on to ease this in) so there will be inherent ringing no matter what but reducing the iterations does get rid of the ripples.