i know what you mean if i had to leave my bike anywhere then i wouldnt fit one as god knows what could end up inside my tank possibly worse then your wee.
More then likely the cap would probably just get knicked.
luckily my bike hardly ever gets left unattended apart from when its locked in the garage i dont need it to commute or anything its totally just a toy for me.
its worth the risk for the sheer pose value and it matches my nice pazzo shorty levers
