Spoke card

One origin of the spoke card was laminated cards inserted in spokes with numbers used to identify competitors in competitive races held by bicycle messengers, in official competitions and in unofficial alleycat races.

Another influence was the practice of placing playing cards found on the street in bicycle spokes in a game known in 1990s San Francisco as Spokepoker.

Although the spoke card is hard to read while the bicycle is in motion, it provides a cheap way to label them in the absence of a proper race number plaque under the top tube, and is less likely to attract the attention of the authorities than a number on the rider's back.

Other city riders sometimes fix spoke cards to their wheels as an affectation of messenger culture.

Spoke cards have evolved to serve such diverse functions as memorials for fallen messengers, as artwork, and as political placards in bike messenger association elections, and even in the 2008 United States presidential election.