But how do you know which products are good? There is no such thing as a truly “unbreakable” lock. With the right tools and enough time, pretty much any locking device can be opened. However, experts like the ADFC point out that thieves usually try to access a lock for a maximum of 3 minutes. Then they move on to avoid attracting attention and getting caught. For you this means first of all: always connect your bike to a solid object such as a lantern, tree or fence. This eliminates the possibility of professional thieves loading the bike into a car in order to quietly tamper with the lock unobserved.

When choosing a suitable lock, you can make a small preliminary selection based on the price. The higher quality the material, the harder it is to crack. As a guideline, special bicycle insurers state that the purchase price of the lock should be 5 to 10 percent of the value of the bike. And the insurers are well informed in their own interest: their goal is, after all, to have to replace as few stolen bicycles as possible. After pre-selecting the price, they recommend that you use the test seals of independent institutes as a guide. In addition, large manufacturers such as ABUS, AXA, KRYPTONITE or TRELOCK divide their range into 10 to 15 different security levels. Which one is appropriate for you depends not only on the purchase price of your two-wheeler. You should also consider when, where and how long you leave it alone.

Although they can be broken even without heavy tools, even the most basic locks have their place in the bicycle market. Renowned manufacturers such as ABUS or RFR also offer them. If you sit on the bench a few meters away from your bike and take a cool drink from your water bottle, thanks to these “immobilizers” no one can get on as you pass by and ride away with your bike. They are also suitable as additional security for individual bicycle parts

If you want to take out your own theft insurance for your bike, you must definitely choose this category. Only a sufficiently secured wheel will be replaced in an emergency. The locks are characterized by particularly stable materials and durable locking cylinders.

Like a folding rule, movable metal rods are connected to each other by eyelets or hinges. When not in use, a folding lock can be folded up into a small size, while if necessary it can easily reach around a lamp post with a length of up to two meters. If the individual links are also covered with rubber or textile, this makes handling easier and prevents paint damage to the frame. However, the complex design is also reflected in the price. When it comes to security, folding locks are on average behind high-quality U-locks in current tests.

The coarse steel chains are often secured with a padlock. In any case, their monstrous exterior appears very solid. However, the security level depends on the material used. Simple steel can be cut through in seconds with a good bolt cutter. This is not possible with hardened metal. However, such a chain weighs a good two kilograms or more and is unsuitable for daily transport on the bike. However, if such a lock always remains on site, for example on the bike rack in the company, it can be a good alternative to a U-lock or folding lock.

The “Fort Knox” of bicycle locks. The hardened metal can often withstand even heavy tools and is rarely cracked on the open road. If a high-quality turntable cylinder is also solidly installed, you get optimal security even for a particularly expensive, sought-after bike. However, the solid steel arch only offers limited connection options. For example, it doesn't reach around a lantern. In addition, the steel construction weighs a lot at more than one kilo. Locks that can be mounted on the frame using a simple mechanism while driving are particularly practical.

The small brackets firmly mounted on the frame block the rear wheel, making it impossible to move or push away quickly. Anyone who sets their mind to it will have a lock like this cracked in no time. But if you just get some fresh rolls and keep an eye on your bike through the window, you can be satisfied with the practical and quick solution for a short time. Such a frame lock also provides additional security for your rear wheel if, for example, you have attached the frame or front wheel to a lantern with another lock.

A light plastic jacket covers a metal wire that is usually only a few millimeters thick. A simple cylinder or a numerical code is used to close it. This protection may be sufficient for a very simple or old bike that is no longer attractive to thieves. Thanks to their light weight and flexibility, cable locks are easy to use. The rolled-up spiral locks can be stretched to a length of one to two meters and can therefore easily be wrapped around a tree or lamp post.

A roll-up wire is secured by a lock with a numerical code. The small, handy models fit in any pocket and are always at hand when needed. The mini lock is not a hurdle for professional thieves. The manufacturers also recommend the models primarily as an additional protective device in addition to another lock. A mini cable lock can definitely protect you from opportunist thieves who want to “borrow” a carelessly parked bike for a joyride.