Trixie Tyler portrays an "evolution behavior study scientist" who believes that Darwin's Theory is ass-backwards: Man evolved from bikers, not apes! Yes, bikers are the missing link, and the 500 pound vibrator of the title is actually her motorcycle, mama! To prove her theory, she provides compilation scenes in her classroom of bikers getting it on in the great outdoors. All the clips you would expect are present, including rough 'n' always ready Holly Ryder, Busty Belle and other biker babes in full regalia.
Trixie's final exam finds her decked out in the classroom as a sexy blonde biker bitch, and she has two male students take her through all her gears, play with her knobs, and really rev her motor right there on the desk. If they had been wearing protection, she would probably have burned rubber!
This is a biker video as well as a sex tape, but everyone should enjoy Trixie's talented tongue-in-cheek performance.