Funny you should mention that. I was talkin' to the youngun next door telling him about that trick. I think the picture was taken in '59 and he played for the Champs in '60.
Position a baseball card on the rear section of the triangular-shaped frame of the bicycle, underneath the seat.
Open a spring-loaded wooden clothespin and clamp the card to the frame using the clothespin. Make sure part of the card sticks out into the spokes on the bike's rear wheel. Attach additional cards in the same manner along the frame in spots where the frame is thin enough for the clothespins to fit around it.
Attach other cards to the bicycle's front fork, which is the downward-sloping part of the frame that connects to the front wheel, if it is not too thick for the clothespins to fit around it. Attach the cards using the spring-loaded wooden clothespins, making sure that part of each card connects with the bicycle spokes. Turn the wheels so the spokes strike the cards as the wheels turn.