Bowerman poured urethane in a waffle iron to prototype Nike's tread

In 1971, Bill Bowerman — University of Oregon track coach and co-founder of Blue Ribbon Sports, the Japanese-shoe importer that would become Nike — faced a problem money couldn't fix: a new synthetic urethane track laid at Hayward Field two years earlier was chewing up runners' feet. Metal spikes dug in too deep and slick flats didn't bite at all. He had already asked established shoe manufacturers to engineer a spikeless, high-traction sole; none were interested.

One morning, watching his wife Barbara make breakfast, Bowerman studied the grid on her waffle iron — a 1936 wedding gift — and poured liquid urethane straight into it, gluing it shut and ruining it. He bought secondhand irons and kept experimenting, filing a patent for the resulting multi-sided tread stud in 1972 (granted 1974). Early versions raced at the November 1971 NCAA cross-country meet; the geometry became Nike's first true commercial hit as the 1975 Waffle Trainer.

Used a household waffle iron as free tooling, pouring liquid urethane into its grid to test a tread pattern no manufacturer would engineer.

A waffle iron's grid closely matched the multi-directional stud geometry he wanted to test.

Pouring liquid urethane into the iron produced a real, physical prototype in minutes, without waiting on manufacturers.

Racing the prototype at an NCAA meet gave direct validation that justified later patenting and mass production.

When no off-the-shelf part meets your spec, use everyday objects as free prototyping tooling to prove a novel geometry before investing in custom manufacturing.

The waffle-soled 'Moon Shoe' prototypes never reached mass retail — only a handful sold from Nike's Eugene store — but the geometry Bowerman found in his kitchen was patented in 1974 and released as the 1975 Waffle Trainer, Nike's first bestseller, with orders topping 100,000 units that year. The commercial payoff landed roughly four years after the kitchen experiment, not the two years sometimes claimed.