Originally Posted by
ZAHANMA
You could technically go lower than 64mm, but it wouldn't be from turning down the current design. It would involve a new design, which had a new, smaller bearing which could still maintain the high RPMs of the supercharger while at the same time being smaller in diameter around the input shaft of the supercharger.
This bearing is only spinning from idle to about 2.5K rpms max. When your charger engages it is no longer spinning.