powerhouse

One day while browsing in a nearby LBS, I noticed that a slightly different type of U-lock was for sale. The U-lock in itself was basically the same except that it was much smaller than older ones that I own. Attached to each lock was a long chain that can't be found in the average hardware store.

With all that I've heard which states that U-locks don't work, what will make this one different and better? Can the lock still be picked with a Bic pen? Can the chain be cut?
Please discuss.

ItsJustMe

None of the locks can be picked with a Bic pen - everyone fixed that hole immediately. OK, you can probably pick up dime store locks that still can be.

There are many locking strategies. The tiny U lock plus chain is one of them. Bigger U locks are fine, I don't know anyone who says they "don't work". You just need to understand their limitations. You use the smallest one you can, so that they can't be forced by inserting a car jack and pumping.

You have to understand that with locks, just like safes, there is nothing that will simply stop theft. All you can do is to slow them down. You want to lock well enough that it's no longer worth it to take your bike.

It's hard to argue with the strategy of "just lock better than the next guy on the rack" either.

noisebeam

Do you mean something like this?
https://bikefactoryhawaii.com/merchan.../knox_lock.jpg

JasonC

Sheldon Brown has a good overview of this; some of which was stated above https://www.sheldonbrown.com/lock-strategy.html