Your over thinking it. V-belt tension isn't that sensitive. If you have to keep adjusting the tension, the belt is streaching. If it's streaching, the fabric core
is dammaged, and the belt isn't any good. Just go ahead and replace it when you start having to tighten the belt all the time.
If you find yourself with a busted v-belt, in the middle of nowhere, use a peice of light nylon line. Wrap it around each pully, and then tie it as tight as you can with a square knot
, trying to have the knot
fall on the outside of the pully as you do. Be sure to cut off all the excess line, and have a rather good knot.
Is it right? No, but you'd be amazed how long a light bit of nylon will run like this. Panty hose works really well too, so just raid your wifes stash.