Originally Posted by BrianBrave
Just re-installing the stock idler pulley and keeping the 185mm and the smaller WP pulley. This would keep the ratio's for all the other accessories the same (including the supercharger) just reducing the ratio (and thus RPM) of the idler pulley to within the bearing range.
I imagine they decided on a smaller idler pulley so to keep the stock belt. (probable some marketing idea)