Perhaps a new bit of HD seat belt/truck strap webbing with a sewn loop on the outside so it neatly slips over the upright and a steel tri-glide for
adjustment on the other, throw the duct tape off and replace rubber with some appropriately sized rubber/foam tube and job done!
edit: the Tri-glides are what I've used for my foot loop adjustment on the 'double trouble' thread here: Double Trouble |