The RoundLock from SecurityForBikes.com 

Hi Steve, Glad you're pleased. You were the first to work out that way of locking the chain in position through the rear axle on that bike - well done, and thanks for sharing the idea! Cheers, Steve.

Hi Simon, We have some ideas about the 22mm chain. Nothing much that we can share so far, I'm afraid, but we would like to use this lock in more situations, yes.

The RoundLock is made from a case-hardened Cr-Mo-Ni alloy steel. It has a 9-disc anti-pick cylinder, protected with a rotating anti-drill hardened alloy steel plate. I guess if you leave enough space for a thief to get a ridiculously big lever into the 'D', and if the lock is fixed to something sufficiently solid, then it might be possible to defeat it with some kind of levering or prying attack. If it is used properly, all this and also a bottle jack should become impossible for a thief to use. We have done tests in a big hydraulic rig and the force required to break the lock is way in excess of the capacity of the compact bottle jacks we've seen on the market. Realistically, an angle grinder is probably the only way to defeat it, and that won't be a quiet attack. I hope that helps, Steve.

PragmasisSecurity. Thank you Steve for the great response. All the info I was after! 👍The chains and locks appear to be one of the best in the market for an out of the box solution that is ready to go. There are pro's and cons to any chain and lock combo with regards for material type, strength, brittleness, ductility, price and weight. Everyone has different thoughts on what is best and different environment will demand slightly different specifications but from my research so far for varying situations, this product gets a thumbs up!👍I will be definitely purchasing one for my new custom trailer...unless you wish to send me a freebie :) Thnx again Steve for the concise reply, cheers