(FORTUNE Magazine) – Extreme sports are all about merging activities, the more simultaneously the better. Enter Matt Hanson, a 33-year-old skier, snowboarder, and mountain biker in Playa del Rey, Calif., who's doing his best to promote a new sport--and industry--by combining his hobbies. Hanson is proprietor of Winter-X-Bike Inc., maker of a $200 conversion kit that equips a mountain bike for the slopes. First question, Matt: Why would anyone want to do that? "So many people have these expensive bikes and can't ride them in the winter."

Hanson didn't invent ski-biking. The sport is popular in Europe, and Hanson counts 30 U.S. resorts that allow the contraptions, which require less athletic ability than skiing or snowboarding. Ski and bike giant K2 markets its Snowcycle for $850, a price point that gives Hanson hope for his do-it-yourself kit. Warning: Gearheads can do the conversion in ten minutes; the less mechanically inclined should visit a bike shop.

Hanson, who's selling kits online at www.winterxbike.com, is angling to perform a demo at ESPN's Winter X Games in Aspen in January to promote the sport. "It hasn't caught on yet," he says. "But when people see how easy it is, I think they'll want to do it. It's just like riding a bike." Well, yeah.

--Adam Lashinsky