The chain is Heavy. The links are Thick. It can be cut with a huge bolt-cutter because that is how I cut off a section at the hardware store ... and I know how hard I had to work (I had to lay my entire eighth-of-a ton into the job, with the bolt-cutters on the floor, and it took a me a few minutes ... and they were Big bolt cutters, supplied by the store specifically for cutting that chain.)

Basically, it would take a guy with a three-foot bolt cutter--if he could stretch the chain enough to lay one leg of the bolt cutters on the ground, which generally I prevent---several minutes wrestling to cut the chain. And anyone with three-foot bolt cutters ... would probably be smart enough to get a grinder ... he sure would next time.

I Believe the lock shackle and chain are 3/8 inch. I am not going to get up and check.

The chain is about four feet in length. I only carry it when I am going shopping someplace, and bring my commuter or rain bike, which have full racks and panniers. Six pounds of lock and chain (or whatever it weighs) isn’t an issue if I am buying a couple gallons of paint or milk or a 25-lb bag of rice.

The lock is definitely the weak point--- picking it would be a lot faster than getting through the chain.

However, as I have said here before and also in this post .... if the lock I am using doesn’t offer me .....

To me a lock is more about a sense of security than security. If someone really wants my bike, s/he will bring the tools and run the risk and steal the bike.

If a person wanted to take the time messing with my lock, I am sure it would give way. My hope is that no one wants any of the bikes I would leave locked in front of the grocery store or the library, enough to stand there messing with it, hoping no one asks or that I don’t come out, take a photo, and send it to the cops.

When I know I will be away from the bike for half an hour or so, I use the Big Chain because it sends a message---“This bike is Locked, sucker!”

In fact, a serious bike thief would sneer, ‘No bike is Safe, sucker!”

I could use a D-lock, but most of the places I have to lock up aren’t bike racks and don’t have convenient metal loops to link through. The chain is the only way to get the bike secured anywhere in an urban or suburban environment.

I am not under any illusion that my bike is ever “safe.” All I need is to feel that I have taken reasonable precautions, so I can shop in peace.

I hope if anyone sees that fat chain on the cheap bike, they will figure it isn’t worth the effort and just not bother. A determined thief ... wouldn’t bother stealing one of my cheap bikes.

For general/emergency use I use a cable lock --- either a cable with a “quick-pick” inline four-tumbler combo lock, or a cable with looped ends with a motorcycle helmet lock.

Either could be sawed through by someone with a steak knife in five minutes, or chewed through with pocket wire cutters in 90 seconds. As I mentioned, those are for totally unexpected stops where I think the risk is low enough or the need high enough.

The Ottolock would be a "one-size-fits-all" lock which would offer as much or more security as the chain with a lot less weight. I could bring it on any bike on any ride and not feel compromised by the weight and bulk.

The only drawback is that it lacks the psychological impact of the chain and padlock. Casual thieves might be more inclined to ty to force it and might damage my bike.

Anyway .... it is all about my peace of mind, my mental security. I can use a shoelace if I think that is enough. And frankly, if I wound a shoelace through the rear wheel and frame enough so someone couldn't untangle it in five minutes, it would be about as secure.

If I Really wanted to discourage theft I would just take both wheels with me. No one is going for a joyride on a wheel-less frame, and no one is going to make any money buying wheels to put on a cheap bike to try to sell it.