Maybe you are thinking of Cindy Whitehead? She had some "assets" too you know... :)
I took this photo moments after Cindy climbed off her bike after winning a 50-mile race with no saddle on her bike. In the process she handed reigning NORBA champion Jacquie Phelan her first defeat, and Cindy went on that year to win her own national championship.
Here is my fotopic.net Cindy Whitehead gallery.
My book, Fat Tire Flyer: Repack and the Birth of Mountain Biking
is at your bookseller and on Amazon