Knog 11558 Party Combo Lock - Secure Bike & Luggage Lock with 4-Digit Combination - Perfect for Cycling, Travel, Gym Lockers & Outdoor Adventures

I am disappointed in the performance of both this lock and the Knog Party Frank cable lock. The only difference between the two is that this one is a combo lock and the other is a key lock. I initially bought the key lock and sent it to my daughter (in college) to lock her new bike. Within a few days one of the three keys bent due to her struggling to make the lock work. Right away I ordered this lock, the combo version, so that she could securely lock her bike while a solution was found. I visited her a few weeks later and tried the other two keys. Though I struggled, with a little work I was able to get the lock to function but it was not at all easy to use. By then, her new lock had arrived and I set the combo on it myself and checked it several times to be sure it was working, which it was. While there that weekend though, it, too failed and I was at a loss. I could not get it off the bike at all as I believe the combo rolled to something new. This happened while I was watching my daughter use it, just after I successfully tested it. Unfortunately I was only able to get a credit for returning this one as the delay in our visit was too long to issue a return on the first. Lesson learned...I ordered a U-Lock from Kryptonite and of course it works perfectly.As a bit of background, I spent a year while I was in college working at a bike store and so have plenty of experience with bike locks. Prior to that I had worked in a realtors office, and I was constantly having to get keys cut and lock boxes set up/taken down and very frequently had to solve the issues that arise with bad keys and or bad locksets. Not that bike locks are all that complicated, but I wanted readers to know that I have more experience than most with locks.