Originally Posted by
fietsbob
can you afford to replace the bike when the budget lock is defeated?
The cheapest lock that you can get for your bike will be about 90% effective because it forces the thief to have some kind of tool to defeat it. As you progress from 90% effective to 99% effective you engage in a progressively more high tech and more expensive game of one-up-man-ship with the thief. There is no 100% safe. If the thief has the time and technology you will ultimately always lose.
Where do you plan to lock up your bike? Check out what other bikes are parked there and try always to park near a nicer bike that has a less secure locking system.