I had them on my first bike, a 1937 red Schwinn, and have put them on subsequent bikes. I make them from strips cut from old leather belts, the ends held together by small license plate reflectors. Anybody ever fasten a playing card to the front fork with a spring clothespin? As a child of course. The sound is like whatever your imagination chooses, an airplane, a motorcycle, a race car etc. I lost two front teeth trying to adjust the sound card with my toe while speeding down the sidewalk in my Grumman Wildcat. A foot became lodged between the fork and spokes, and when I regained consciousness, my face was on the sidewalk with the bike on top of me. That happened many sets of dentures ago.
George Jones
Dallas, TX