This is a rather interesting one we discovered browsing usage dictionaries.
Barbel is a ‘one of the slender, whiskerlike tactile organs extending from the head of certain fishes, such as catfishes.’
Barbell is something most men use at least once in their life.
It a metal bar with weights at each end that is used for exercise and in weight lifting: “Barbells are used in gym, and at times at home, to punish one’s lover.”
The school athlete excelled in the use of the barbell; in addition, he had a large rare fish collection at home, and one of these fish had a barbell hanging from its mouth.”