pillion complaint/numb balls (?)

[gethyn]

neither me nor my pillion have got fat arses. when we ride together there's a gap between us and she slides down from her 'ledge' (by that i mean the raised bit of the seat) and finds herself with her arse half on the ledge half on my part of the seat. she's uncomfy and my balls turn blue. she has to shove herself back to get back onto her ledge.


if i lay over the stank my arse skoots back and fills the gap but i'm not going to ride all day flattened over the tank.


has anyone experienced this? and if so have you solved it? i guess she's going to have to lean on the tank but she's small and i hardly notice her presence on the bike and she likes to cling to me a la koala bear.


we've ridden many other bikes together and never had this problem.


any advice gratefully received.