Exactly 100 years ago, a Brooklyn woman in her 20s set out from New York on a Harley-Davidson F-11. She took along her mother in the attached sidecar.

Together, Effie Hotchkiss and her mom, Avis, became the first women to drive coast to coast on a motorcycle.

A century later, women are still in the distinct minority when it comes to riding on two motorized wheels.

According to the Motorcycle Industry Council, only about one of every eight motorcycles sold is bought by a woman. The Council estimates that about 25 percent of all motorcycle riders are female, but many woman who ride think the percentage is much less.

Still, manufacturers put a good deal of effort into trying to appeal to women buyers.  Harley-Davidson holds garage parties to introduce women to cycling, and to Harley models that might appeal to them. This weekend, Kawasaki is introducing a similar event, Koffee Break, at its headquarters in Irvine, California.

Motorcycle companies were slammed by the recession, and they haven't recovered in the way the auto industry has. Women represent a large, untapped market, so nowadays, virtually every motorcycle brand is building bikes with smaller engines, shorter saddles and adjustable ergonomics–all things that play to women riders.

Interestingly, Harley, known for its big and beefy bikes, sells more motorcycles to women than any other manufacturer. Much of that might be the storied brand, but Harley is not lacking in marketing savvy. Last year, the company released results of a survey which found that women who ride motorcycles say they are more satisfied with their lives, and they feel sexier, too.

There are a number of organizations and publications devoted to women riders.  One good place to start is Women Riders Now.  The site has lots of information for beginning and experienced motorcyclists.

Susan Carpenter is auto and motorcycle critic for the OC Register, and joins Take Two on Thursdays for The Wheel Thing.