I've probably proved myself wrong on this. Walked over to my 50's Raleigh track bike and banged the nose of the saddle which then moved downwards! -- but I hadn't checked the attachment for a while. Anybody got a period prop rod for sale? The suggestion that a bike might generate over 2g on a short steep track is rather high. A quick calculation indicates less than one and a half g, probably closer to one and a quarter. However, I have ridden a 120 metre track with bumpy joints that would test any vintage saddle attachment. A stayer would more likely need a front saddle stay because of a more forward saddle position.
Hugh Thornton