NEVER lock anything up w/ ANY cable device. Clearly you went the safer route w/ the u-lock. BUT u's get broke on a fairly regular basis. Cause the perps can see your brand label 20 feet away, next stop is YouTube on how to crack that specific u-lock, then time to go bike shopping. NEXT time you are out and about in chi downtown, look at what Bike Messengers use. 90% will be case-hardened chain, mostly w/ a monobloc style padlock.