Originally Posted by PaulRivers

I'm not sure where the point is, there's some sort of point where with to low of tire pressure you start risking pinch flats. This applies more to skinnier tires than fatter ones - you can run 4" fat bike tires at 5psi fine, but I wouldn't run skinny 23c road tires at 20psi.

Not sure if 60psi on 28c tires is fine or not.