My BW (She Who Must Be Obeyed) has become enthused with road riding and joined me on a 20-mile excursion over the weekend. She's pretty happy with the accomodations, an elderly but quite serviceable Schwinn Traveller, but she has one problem. Her left foot goes numb after a few miles. She's using platform pedals and New Balance running shoes so there shouldn't be any pressure points, and her upper-leg / lower-leg angle is about 30 degrees at the bottom of the pedal stroke, so I believe the saddle height is about right. She reports no discomfort with the saddle itself, a split-top Schwinn product.
As I'm really pleased to have her ride with me, I'd like to solve this problem as soon as possible so that she doesn't become discouraged. Any suggestions?