What does the 13 mean for bikers?

What does the 13 mean for bikers?

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””.

See also  Do I need to insure a bike SORN?