I didn't know knobs came in different sizes ... I'm sure mine must be big knobs, just a bit worn down perhaps. Could explain why I slide around so much, but then again I should probably go faster for grip, but the ex always said I was too fast so I am confused. You'd be very welcome Jeff, I shall sling another hammock under the verandah or sweep (shovel) a corner of the shack clear if you ever come over this way.