fully agree that pickies of an "adult" nature would lower the tone of the site, an bring wierdos here, an that may spill over to the boards an chat.
clean and friendly wins over more than smut..... but i can see what your thinking matt trying to get new peeps on here, have you thought of doing an on line photo albumn of the bikes, nights out, rallys they go to, also you could have a comments section for members to write what they think of a particular rally/meet an mates meeting, also trips out could be arranged cos it doesn't have to be just rallys where peeps meet, but post the meets on for subscribers to view, not others.
also have you thought about allowing chat for a months free trial but after that time subs only ??
theres also the idea of auctions to raise funds peeps donate items then people bid on them, on one site we did an xmas tree comp sent a pickie in an the winner got a months free subs.... you could do best decorated bike/car/ sidecar !!!! just a few of many ideas but would bore you all with it !!!!