yes the inner race of the top bearing is clamped down by the top plate/bell. so it sounds like the outer race slip fit is by design. the more I think about it, I don't how you would assemble the spindle if that outer race was press fit. The spindle shaft is already constrained in height by the preloaded pair below so you would have to press in the top bearing with a sleeve on the outer race from the top and stop at exactly the right height to not preload the bearing with some random amount as the inner race stops on the shoulder of the shaft. so I can see why that would need to be a slip fit. I'll still contact the seller and another spindle shop just to male sure. It's still hard for me to wrap my head around how that outer race isn't just going to wear into the spindle bore over time and eventually get enough clearance to start turning faster and causing real damage, but maybe it just won't move at all once I tension the belt.