Originally Posted by
lowkey
EDIT: didn't see that cooter explained it but this will elaborate a bit more on the subject and make it more clear.
less fuel under decel = higher AFR (in excess of 18.0-1) = RPM dropping MUCH harder = possible locking up rear wheel on down shift...
My bike was just short of skidding on downshifts now it is like a slipper clutch.
Try for yourself, add 2% fuel to the bottom 2 rows of fuel cells across all RPM. Do 40mph in 5th gear and see how slowly your bike looses speed compared to normal with no throttle input.
I believe it is a combination of compression an no longer being a power stroke (no fuel burn to force piston down, next piston cycle same deal = stopping crank mass from rotation that much sooner).