A Quick Way of Shortening a Rope
This is an idea that might be useful after a spell of dry weather. If your ropes have suddenly become much too long, it is a lot of trouble to go and adjust each one on the wheel. Instead, you can tie a small wooden peg into the rope between the garter hole and where the surplus rope is wrapped around the central spokes of the wheel. The knot suggested was a Marline Spike Hitch, (fig.a) but I think that a Clove Hitch would be just as good.
Of course, if you want to avoid this problem altogether, then ropes with synthetic tops are a lot less prone to shrinking.