Couple of things:
It's a good idea. I would probably use it with a larger lock and larger diameter chain. So don't take my criticism as me just being mean.
24" Harbor Freight bolt cutters will defeat the lock you show in less than a minute. I've done it.
That 1/4" chain will not hold up to bolt cutters. I tested Grade 100 chain in all sizes up to 1/2", and 3/8" was the smallest size that could not be cut with one person on some 36" hf cutters. I think your cutter in the video was either dull or you are not very strong.
The grinder demos were not relevant because the lock will always be there to be attacked. No lock can hold up to a grinder. The best bike lock designs REQUIRE a grinder so the thief will be forced to make noise and take time. You need to focus on making it bolt cutter-proof.
Last edited by Jiggle; 05-13-14 at 05:25 PM.