What does the number 13 mean in the biker world?

What does the number 13 mean in the biker world?

The letter M, being the 13th letter of the alphabet, often is said to stand for marijuana or motorcycle. Generally, it is assumed someone wearing a 13 patch is either a user of marijuana or other drugs, or is involved with the sale of them. The M also has been known to stand for “”methamphetamine””. Jul 29, 2016

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