Originally Posted by
gsa103
Expensive U-lock's are marginally better. Your current lock is probably fine given that its a cheap bike. Your U-Lock should be immune to bolt and cable cutters. That leaves the bike thieves "I-win-button", the cordless angle grinder.
The difference between your lock and a Kryptonite is something like ~30sec vs ~2min for a Kryptonite. Keep in mind many thieves don't carry angle grinders, and those that do are likely looking for nicer bikes. Most theives are looking for easy targets, and any decent U-lock is not an easy target.
Cheaper U-locks have a lock that can easily be picked. If you want a system with good thick hardened steel, good lock and good holding mechanism that prevents brute force breaking, you need to pay more. Unfortunately.
U-locks over 50 euros usually leave thieves with angle grinder option only, which few of them carry. Those cheaper leave them with ability to pick the lock, force open the lock (on some models) or just cut them with bolt cutters if they're not at least 12mm of hardened steel thick.