A Bath man was killed Friday when he failed to handle a curve on his motorcycle and crashed into a guardrail on the opposite side of the road, Bath police said.

Police say the crash happened about 5:20 p.m. and killed Mark J. Lebourdais, 52, of Bath. Police said Lebourdais was riding west on Wingfarm Parkway and failed to negotiate a right-hand turn in the road.

He was not wearing a helmet, and police said excessive speed appears to be the primary cause of the crash, although the investigation is continuing.