According to Nova Scotia's Globe and Mail newspaper, Judge William Digby rejected Davis' arguments that helmets do little to enhance safety, and said on Monday that Davis should pay his fine.
Davis, who wrote an anti-helmet book in 1998, had told the court Nova Scotia's helmet law interferes with his constitutional rights to liberty and freedom of expression.
Judge Digby accepted expert testimony that the law prevents head injuries.
Davis has 30 days to lodge an appeal.
I think the battle is worthwhile because it brings the matter to the attention of the public, said the 53-year old Halifax photographer.