I've always been at a bit of a loss as to how to secure my bikes when away from the pitch - there's not always a stout fence or a tree to padlock the frames to. I bought a large screw in post, designed to attach a dog lead too. It's quite hefty, about 1/4" in diameter, and about a foot long. I then padlock both bikes to the loop at the top. If anybody wanted to unscrew it, they would have to pick up the bike, or bikes before they could turn it out - just abbout impossible!! Not foolproof, of course, but it would certainly make a thief think twice, or even thrice!!