A split second is all it takes. You're at the intersection of Sunset Boulevard and Pacific Coast Highway. Slow Sunday morning at continent's edge -- blue surf below, sun crawling over the bluffs above, all quiet on the western coast. Then you hear it. Nothing much at first, a hum in the hills. Then a growl, and don't blink or you'll miss it: a Harley Sportster 883 going west like a bat out of Hollywood, ridden by the finest redhead you've ever seen, a blur in black boots, a low-cut shirt and a cloud of exhaust. You've just met Tylyn John, the best thing on two wheels since Harley met Davidson. Daughter of Motocross champion Tom John, pride of the ragtag bike brigade that rides Sunset to Malibu every Sunday, Tylyn never stays long in one place, so pay attention while we list her specs: 25 years old, fiery as her red hair and Irish blood, often engaged but never married, scourge of speed limits, friend to animals and to ruggedly handsome but sensitive men. Still free to aim her bike wherever she wants to go, she is as uncommon as her name. Which, for the record, is TY-lyn. Rhymes with smilin', which happens to be her reaction to rocketing down a two-lane blacktop at speeds approaching triple figures. "I'm not very patient," says Tylyn. "Wherever I'm going, I want to get there fast."

Her hobby once landed her on the cover of a biker mag that advised, "Don't accept any challenge to race. You'll probably be walkin' home." Her name caused trouble when she was a kid at summer camp; the camper known as "John Tylyn" was stuck in the boys' dorm until her tears convinced counselors there'd been a mistake. That was the last time anyone mistook Tylyn for a boy. Tylyn wears diamonds on both hands and both ears -- gifts from her admirers, one of whom was so ardent that he gave her a hefty diamond after they broke up. "I love watching her in action, seeing guys fall all over her when she blinks her eyes," says her friend Mieke Lanter. Latest to fall was rodeo cowboy Ricky Guillory. He proposed last year and she said yes. Can a professional steer wrestler corral the fastest woman in the West? Who knows? Not even Tylyn can predict Tylyn's next move. "Life," she says, "is a matter of opinion. Good or bad, it's what you decide it is. I like going into the next turn without planning what I'll do when I get there."