I am a product design student studying bike security and have spent the past month studying bike locks. We spent the past few weeks acquiring locks and trying to break them with various tools that thiefs commonly use and I'm sorry to say it but it is suprisingly easy to get through most locks these days. I agree that Kryptonite locks are up there with the best and motorbike chain locks are also good but very heavy.

I'm trying to come up with a new bike locker service for commuters and I'm currently at the design stage with the view to getting this manufactured. If you have a spare 30 secs and would like to contribute to the design of this and fill in a really quick 30 second questionnaire it would be very much appreciated and taken on board.

http://www.surveymonkey.com/s/SS3FLRT