When Brando departed for that great motorcycle rally in the sky, he left not only a movie legacy but the style he jumpstarted with 1953's The Wild One: biker chic. Not only is moto gear continuing to get a workout on film (from Uma Thurman in Kill Bill and Gael García Bernal in The Motorcycle Diaries to Ewan McGregor's bike-umentary, Long Way Round, premiering Oct. 28 on Bravo), designers are all over it these days: The classic zipped leather jacket now comes courtesy of Dolce & Gabbana, Ralph Lauren (who did a quilted version), Donna Karan (who put it in python for spring), and Versace (who colored it pink). Bottega Veneta's new knee-high biker boots go for about $980; Chanel poshes up theirs with patent leather straps and tips. Embodying the new ''chick grit'' are current Harley-Davidson models Melissa Etheridge and Shirley Manson of Garbage; other boldface fans of crotch-rocket chic include Paris Hilton and Vivica A. Fox (who own Tommy Hilfiger jackets), Biker Boyz star Tyson Beckford (who prefers Sean John's), and Mary J. Blige (Catherine Malandrino). ''Motorcycle fashions are the perfect clothes for scary times,'' says Charles Falco, who co-curated ''The Art of the Motorcycle'' for the Guggenheim Museum in a 1998 -- 2003 show. ''It says, 'I'm protected, I'm rebellious, and I live dangerously.''' Falco reminds us that for young Ernesto ''Che'' Guevara (played by Garcàa Bernal in Diaries), the motorcycle was the very vehicle of his awakening revolutionary spirit. ''The bike and the leather jacket are symbols of rebellion and freedom and have been for over 50 years,'' Falco says. ''When we conceived our exhibit, it was because the motorcycle epitomizes most of the major themes of the 20th century: danger, speed, sex, and technology.'' Speaking of scary: One by-product of the success of Diaries could be the comeback of distressed leather jackets. Now that's something worth rebelling against.