I've got a ttr230 yamaha which i ride on the road and to work. I was worried the other day that i have gone to all these troubles locking my bike up to poles and with a disc lock.. but if someone put something in my petrol tank and i started riding it then it could get really stuffed! Being a dirt bike it has the normal big screw on petrol cap and was wondering if there is some way i can lock it shut?! like maybe a cap with some sort of lock?