Kryptonite U-lock (14mm round shackle, weight of 3.75 pounds) that doesn't easily go around the frame, back wheel, and rack:

http://www.kryptonitelock.com/Pages/...PNumber=999348


Kryptonite "mini chain" (10mm hex links, weight of 4.40 pounds) that does easily goes around the frame, back wheel, and rack:

http://www.kryptonitelock.com/Pages/...PNumber=000792


They both mysteriously have a security rating of "8", despite the chain being 10mm and the U-lock 14mm. Similar price.

The chain's made of "3t manganese steel" and has hexagonal links. Would that make it as hard to cut with bolt cutters as a 14mm round and merely "hardened" U-lock shackle?

Or do you think the chain would fall to the 2-foot bolt cutters that the petty criminals in my small city seem to favor, and the U-lock not?

Is that integrated lock on the chain bound to end up having some exploit? It says "Patent-pending end link design secures chain to hardened deadbolt eliminating critical vulnerability". Suggesting that the chain on the previous model could be pried off with a toothpick.

¯\_(ツ)_/¯