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A note on the bow stringer

The bow stringer I have came with instructions to step on the string with both feet about shoulder width apart. I didn't understand why, especially since some instructions elsewhere (and here) say to stand on the string with one foot. Today I think I figured out why, at least with my bowstringer.

The cup, which covers the upper tip, into which you are trying to slide the bowstring, has a tendency to cover the tip more and more closely, eventually pinching off the notch in the tip into which you need to slide the bowstring.

By standing with your feet apart, you cause the tension in the string to act more perpendicularly to the limb, and so the cup is less likely to slide inwards and cover the notch.

If you stand with only one foot on the stringer, or with feet close together, the string makes a shallow angle with the limb. This pulls the cup more tightly onto the tip, sliding it over the notch.

An additional benefit is that you are causing less tension in the bowstringer.

(Note that the bowstringers in the links do not have a cup that goes on the upper tip - they have a saddle, that you place over the limb. This difference in design probably accounts for the difference in optimum technique.)
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