This is a heavy duty lock, being heavy duty means it's also physically heavy. It doesn't bother me because I work in the city so the weight is worth the peace of mind the lock provides however it might be a negative to some. It's also awkward to transport which is probably why people tend to use U locks here.

Knowing that a professional bike thief will get your bike if they have enough time (a minute or two at most) I wanted a lock that would give them more trouble than most other bikes on the rack. I figure this will deter a professional thief from choosing my bike over an easier target. A video on YouTube by "bosnianbill" convinced me to get this lock. He takes locks that viewers send him and tries to pick them to see how secure they are. He basically had to destroy the lock using methods that a bike thief likely wouldn't have at their disposal. The video is called "(397) Kryptonite Autopsied - One TOUGH Lock!!!" if you want to watch it.

The only negative that bothers me I can think of is the fabric around the chain seems to attract grease and since it's black you don't see it till it's all over your hands or your clothing. Ideally you'd have a dedicated pocket in your bag for the lock otherwise you might want to have a plastic bag to put it in so your bag and anything in it doesn't get ruined. I started carrying around a small stuff sack to put the lock in.

I live in Long Beach, CA the city of stolen bikes. I've seen people get there bikes stolen right off there front porch for having a low quality chain. When I saw this product I was hesitant at first because everyone says there chains are unbreakable... blah blahh blahhh. Well let me tell you folks this company is TRUE to there word. I left my $500 moped scooter outside (STUPID RIGHT?! wrong) and of course I wake up the next day to find my chain tampered with but to my surprise my moped was still there!!!! I've had this chain for 3 years and despite the multiple attempts to brake the chain no one has been able to. Long story short is if you have something that is valuable to you buy a Krytonite chain. #NoMoreStolenBikes

It's well made well for what it is. A thicker chain would be much to heavy, although it would not prevent thefts using a large pair of bolt cutters.

Pros: light, has insurance for $10 covering up to $500 for one year. You can get up to 5 years for about $30.

Cons: a little fussy to reach around, put the chain into the keyed portion, and close the lock without losing position on either the key or the chain. If you are planning on going through a wheel, a U lock is much easier. I did not realize quite how much a learning curve this would be. Hoping it gets better, but it loses a star because of this.

Also, Amazon sent a new lock without a set of keys on it. I returned it and they cross shipped a replacement. The replacement was obviously used. It was not in the new packaging. It was a little dirty.

I am keeping it this time. I was done hassling with them over this, I need this so I can ride by, and they did cross ship. The lock will get dirty anyway, and who cares about the packaging? Besides, this is the product review. I include this here because you cannot give a seller review when the supplier is Amazon LLC.

Using this to secure a low-cost store bicycle, and while I don't want the bicycle to be stolen, it's hard to bring myself to pay more for a locking mechanism than was paid for the bike. This was the right blend of price and product for me.

I checked the links on each end as best I could, and the welds were complete. Without tearing apart the chain cover, I cannot verify the integrity of the welds on the other links.

The locking mechanism works well, and I've tried it a few times now. This won't be used in bad weather, so I'm hoping the lock won't have issues which others have run into. If the mechanism ever fails, or peril befall the chain, I will update the review.

As with any method of securing valuables, there's no foolproof method, because there's always a way around security. For u-locks, it's a jack/press, that's why I like chains or super-thick cables, but they too have their weakness. So do your best to review products and make an informed choice.

SUPERMAN DIDN'T STAND A CHANCE AND NEITHER DO BIKE THIEVES

I DON'T KNOW WHERE TO BEGIN

Do i begin with the design of this strong lock, the color and locking mechanism or do i began with the way it locks it down. This is hands down the BEST lock I have bought. Other than the really cool name it has an amazing locking mechanism. The lock is on the side and it unlocks/locks with the turn of a key. It is a very strong lock and long enough to lock up my bike and baby carriage(see pictures) This lock is a very good buy, I went against a lot of negative reviews and tried it out for my self. The issue that you have to turn the key and fight it to lock/unlock is PROBABLY because you are putting it into the hole the wrong way. The lock has grooves in it that GUESS WHAT matches the correct side of teh key. Match it up and it locks/unlocks without a hitch. This key is strong and very durable. I withstood a pounding an ddin't let me down. I will be reordering for sure!