Herbert W. Morse, 66, director of community relations with the Bicycle Manufacturers Association of America, died Thursday at his home in Falls Church. He had cancer.

Mr. Morse joined the BMA in New York City in 1973 and moved to this area when its headquarters were transferred to Washington in 1975. His assignment here included work with the League of American Wheelmen, the Washington Area Bicyclist Association and the Federal Bicycle Council. He was the BMA representative on the transportation research board of the National Research Council.

A native of New York City, Mr. Morse attended New York University. He worked on newspapers in New York, Connecticut and New Jersey in the late 1930's. During World War II, he served in the Army in Europe.

Mr. Morse began his career in public relations in New York City in the early 1950s with the Diamond National Corp. He was director of public relations for the Slick Corporation before joining the BMA.

He was a member of the Public Relations Society of America, the American Society of Association Executives and the Publicity Club of New York.

Survivors include his wife of 29 years, Monica, and two children, Karen and Phillip, all of Falls Church, and two brothers, Bernard, of San Francisco, and Lester, of New York City.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society, or to a charity of one's choice.