Masterlock ULock Key - Black

It is very small for my bike

I purchased the Master U Lock back in '09 and it was working fine with no problem. Well, after a year of use the locking mechanism was "sticking" as many have listed above. I dealt with it as best I could. The final give was when it popped open and fell off my bicycle frame while it was locked to it on the way home. I hate carrying locks so I lock 'em to the frame but I was so embarrassed that it popped open and fell off I just left it on the road. Sorry for littering. Master lock make better products please. To potential buyers, Kryptonite makes durable products. Since then I've purchase a lock form Trimax. No complaints yet and very durable. Be sure you DON'T buy any lock with cylinder keys. They can and WILL be opened by a plastic BIC pen. Thanks You tube for that one. Hope my review helped.

bought one of these now the key doesnt work so i cant unlock my bike.

I was using a bulky chain and a padlock prior. I just switched to this feeling that it would be pretty safe parked outside the honors dorm at my university and my bike got stolen with it locked up using just this lock. For security, I can not say it is very good. Other comments, the lock rusted over 6 months, but still worked fine and the key was a bit off but worked alright

I tried this lock for the first time and the keys do not open the lock. Keys also feel very flimsy, so even if they did open the lock they would likely break. Pacific Cycle customer service number did not connect to anyone who could help and just asked if I had an extension number. Please do not buy this lock to encourage Target to stop carrying such inferior products.

The key broke off into the lock the first time I tried to use it. Key NOT durable at all. Don't buy this product. Go to a local bike shop and buy one. It's not like the older, durable version that I used to have. This one is terrible. Returning it tomorrow.

key broke in the lock a week after purchase

My bike was stolen as a result of this product. It was destroyed using something like bolt/rebar cutter and the company offered no service. I highly discourage purchasing Master Lock NO. 8170D.

Like the other reviewers, ours broke in about a month or two. Which is weird because I have an older version of this from 5 or 6 years ago that is bullet proof. Rain, snow, mud, just keeps working. This new design is terrible though.

I have used this product for several years with no problem. It mounts on the bike when not using. Just don't lose the key.

I got 3 of these for 3 bikes and every one of them froze up after a few months of use. The keys do not work and we did not get them mixed up. The bikes were in separate locations, like dorms and cities. The keys would start to 'stick' so I recommended everyone go EZ on the locks. Then, each lock began to have the same problem - the key would not open the lock - either it would not turn or it would turn but the lock would not pop open! A disaster! Missed appointments and classes. I went to a local bike shop here in Cambridge and the guy showed me how bad the locks were - they were EZ to pop with a pen. I am taking all 3 back but I doubt I will get a refund -past dates - but Target should junk this lock. I can't be the only person with this problem!

I purchased this lock and happily involved in owning my new bike only a few days ago. I chose it because it was the most expensive and durable looking one they had at the store. I figured they would need a blow torch to get it off. Imagine my disappointment when I came out after work to find my bike and lock gone. I made sure the lock was securly on and figured that it would be safe on busy Clark street with lots of police and foot traffic passing by, leading me to wonder how easy it is to tamper with this lock. My advice is to purchase a much better lock at a local bike store.