Like others I would try to avoid leaving the outfit in any service area, but if you have to what about a chain ? A Sold Secure chain and lock take up very little space - mine came in a strong but small plastic box, and its quite quick to put on - you only need to thread the end through the wheel and put the lock on. I can't see even the most brazen thief taking an angle grinder to it in a public place, but I could imagine getting in through a window on the blind side.