Kelton conducted the survey and interviewed 1,013 U.S. adult female riders and 1,016 U.S. adult female non-riders. The survey also found:
-- More than twice as many always feel happy: 37 percent of riders vs. 16 percent of non-riders.
-- Nearly four times as many always feel sexy: 27 percent of riders vs. 7 percent of non-riders.
-- Nearly twice as many always feel confident: 35 percent of riders vs. 18 percent of non-riders.
-- 53 percent of women who ride cite their motorcycle as a key source of happiness and 74 percent said they believe their lives improved since they started riding.
-- 51 percent of riders were content with their physical intimacy vs. 35 percent of non-riders.
"Riding a motorcycle is the ultimate form of freedom and self-expression, so it makes sense that women riders are happier in life and, in general, feel more fulfilled," Claudia Garber, director of women's outreach for Harley-Davidson, said in a statement.
The survey was conducted May 20 to May 28 and has a margin of error of 3.1 percentage points.