I, like many women here, started off as a passenger. With time and some reading (Total Control by Lee Parks), I became quite good at it. I rode as passenger on my guys Sprint ST 995 and his best friends 749. His friend complemented him on my ability to be a good passenger, and he is a very aggressive rider. Here's some things I learned.
TRUST
she needs to be totally comfortable with your abilities
RYTHYM
the right moves, in the proper sequence, with precise timing
SIGNALS
you need to establish some touch signal to let her know your intentions.
a touch on her calf when you plan on really getting on it, will keep her on the back.
she can also signal you by touching you somewhere to let you know the pace is too fast/slow
MONKEY SEE, MONKEY DO
she should try to be as unobtrusive as possible, by mimicking your movements.
You lean, she leans the same amount as you. You tuck, she tucks, etc.
The key being no sudden movements.
HOLDING ON
she should keep her arms around you so she can get her hands on your tank for stopping.
this will keep her weight off you, and she can do a quick flip of the wrist to hold on. her legs should do most of the work. She should dig her toes or heels into the sides of the passenger peg brackets to give her a solid connection to the bike. She can also use her thighs to squeeze the rider for stability. Being a passenger is a total workout.
ALERTNESS
the one eyed peek over your shoulder will keep her looking ahead, so she's ready when the unexpected happens. she should look to the inside of the turn.
DID I MENTION TRUST
if she doesn't trust your abilities, don't ride with her until she does...
if you don't trust her as a passenger, don't do it.
[thumbsup]
good luck
