ONGUARD8020 Mastiff Integrated Key Chain Lock - 3.57' X 0.39"[110CM X 10MM] Black

This chain is well built and sturdy. Comes with several extra keys which was a bonus. Nothing is 100% against bike thieves, but this does give me an extra layer of security. It will definetaly slow down the bad guys.

I struggled to figure out how to use this the first time, because I thought there was a trick to turning the lock and removing the key.There’s no trick. Basically if the key is in the lock the lock opens. You can’t remove the key unless you lock it again. This is a rather genius way of making sure you don’t lose your key.Now that I understand it, it’s super simple to tie my bike up anywhere in just a few seconds.The chain is heavy duty, so this is not a fun thing to carry around (heavy). I keep it in a pannier on my bike, so it never really bothers me. Another option is to wrap it around the top tube several times and lock it in place while on the go. No need to keep it in a backpack.I got the smaller size, and that's more than enough length for securing my bike everywhere I go (unless you are tying it to a tree).It's a rather menacing looking lock, so unless someone is traveling with a saw, your bike isn't likely to become a target. I was tempted to buy some of the cheaper options, but I am SO SO glad I went with this one. I feel very confident about my bike being secure wherever I leave it. Definitely worth the money.

This lock is no joke. The chain is heavy and there is no denying that. The lock is a bit silly in my opinion. The key doesn’t easily slide in and it’s very ambiguous as to whether it’s locked or not (click feel when turning key). The key doesn’t come out when it’s unlocked - which is very clear - but I would rather have a more traditional @click - it’s locked” type of feel.

I have only had this for a little while but so far I am really impressed. Construction is very good I am confident that it will deter any would be thieves. On some chains that I read about before ordering this one a common complaint was the lock being hard to unlock, so far my lock opens smoothly with no problem. The main key is very nice with a light to help you unlock the chain in the dark. 4 extra keys come with the lock with the ability to order more if you need to which is very nice. I was a little apprehensive about carrying a bulky chain but it curls nicely under my seat and I don't really feel the extra weight.

I bought the Onguard Beast chain initially, but it was a little overkill for my son's bicycle. This one is lighter and is still a great deterrent for anyone looking for an easy bike to steal. Cables can be cut very quickly with small wire cutters by doing small nips. U-locks are stiff enough that a hack-saw or portable grinder makes easy work of the lock. A think chain is best because it's hard to hold in one place to cut, it's thick enough that even bolt cutters can't get through it. Nothing is 100%, but this will make a thief look for a easier target.

Really strong chain, comes with 4 spare keys too. I wouod suggest this if you have an ebike, it’s very heavy and will be awkward to carry on a normal bike.

This thing is a BEAST. Nicely manufactured and very high quality. The protective sleeve over the chain is a nice touch, as it prevents scratching of your wheels. I also like the key mechanism, which is well protected and works very smoothly. My ONLY complaint... and it's obvious... is the weight of this thing. Its heavy to the point where I HAVE to wear a back back to carry it around. You're definitely not going to wrap this around your frame or something when you're riding. And I'm on a 125cc motor-scooter. Either way, it's gonna take some work for someone to cut through this thing.

My bike has not been stolen yet. Who knows how many bike thieves passed on my bike, I’ll never know. This chain is heavy duty and appears to be good quality. I also like how the lock holds your key when it’s unlocked, until you insert the other end back in again. So your keys won’t fall to the ground while you’re wrapping the chain around your bike.