Knog Strongman stiftung warentest German Test Authority.

Bikes are easy prey for thieves. Even the most expensive locks do not always provide a high level of security.
Picture this: An inconspicuous person is standing next to a bike, then at the appropriate moment they pull out a tool, remove the lock and ride off on your bike. What remains are the sad leftovers of a ruined lock.


This happens thousands of times a year, even in broad daylight.

The remains at the scene are mostly coiled cords. These are the best selling bike locks – cheap, lightweight and flexible. What many do not know is that a pro can crack the thin wire along with plastic cover with a suitable tool in less than 15 seconds. The police often refer to these locks as ’’gift ribbons for thieves”.


For this test we considered U-locks, armored cables, chain locks and Folding locks. These locks can cost up to 120 euros, with some suprising results! Even with these relatively high-quality products, only 5 locks were rated as “Good”.
Our buyers bought the locks like any other customer at the store, and purchased five of each lock. Overall, they purchased almost 200 locks for the institute, of which the majority is now scrap.

Bolt cutters, saws, pliers and other tools were used in the test, as well as more non-destructive, ’’intelligent’’ picking methods.



The bottom line, was that most test candidates could be opened without too much effort within three minutes. Note that: No lock offers a hundred percent security. With the best tool every lock can be compromised.

Tip: Lock your bike up where a thief has to worry about being seen. Keep it in a safe place at night.


One realisation after our attempts to break the locks was that various locks can often only be opened quickly with special tools. Therefore most thieves do not want to carry around a lot of tools, so specialize in one type of lock only.

Tip: Secure your bike with two different models of lock. For example, with a good U-lock and an armored cable lock. That way you can lock the frame and the front and rear of your bike at the same time.

Of the 37 locks we tested 15 were dangerous candidates in other ways. Their plastic overmouldings contained many problematic plasticizers such as DEHP (diethylhexylphthalate), which when in contact with human skin or injested can cause serious harm.

Hazardous substances should not be found in consumer products.

Typically this is a U-shape lock with a removeable closing bar mechanism.
Usually relatively safe, however not every hardened steel lock proved to be sufficient in the test. These locks can be transported easily in combination with a good mounting bracket.


These compact foldable locks are spacesaving and can be easily transported. Compared to rigid padlocks they offer more possibilities to lock your bike. But beware: Most Folding locks are relatively easy to compromise.

Often easy to crack. These locks contain a hidden braided steel cable inside a sleeve of armoured metal plates encased in a plastic sheeth. Caution: The examined locks could be compromised easily.
Test-Comment: armored cable above all should be used as an additional safeguard.

Mostly simple chains with a closed padlock or with integrated closing mechanism. A plastic coating is often used to protect the bike from scratches. These locks are flexible and relatively long, therefore offering more options for locking. Most chain locks come without any mounting bracket and are therefore usually secured around the seatpost. Caution: The examined locks were often relatively easy to crack.
Test-Comment: Chain locks are relatively cheap. heavy, but still often not safe. recommended as an additional safeguard.

Tested: 37 bike locks, 13-U, 6-fold, 11 armored cable and 7 chain locks.

An expert and two assessors without specific education tried to crack the locks with different tools (including bolt
cutters, saws and pliers). In addition, an expert tried to open the locks “intelligently” (with professional picking tools).
There were 3 minutes given for cracking the locks. We assessed the time required to open with the various tools. Three men and two women tested (different ages and with different specific training) opening and closing (including operating without instructions),

Tested the corrosion resistance of the locks after 96 hours in a salt spray chamber according to DIN EN 15496th.

Analysis of the shell PAH (polycyclic aromatic hydrocarbons) inspired by CEC 01.4-08 and phthalate plasticizers. The plastics of the defective locks recorded several high DEHP levels – up to 30 percent – analyzed.

Lock with something stable: The best lock is useless if it is connected to an unstable object, which the thief can easily dismantle or destroy e.g. a lamppost or well secured bike rack.

Coding scares: Police, workshops and bike clubs offer to engrave a number – in addition to the frame number. This code and the label “Hands off! My bike is coded “ increase the risk for thieves and dealers!
Locking up: The longer and more flexible, the lock, the easier it is to connect wheel and frame at once.

Our Tip
The winners are U-Locks the Knog Strongman (85 Euros) AND Abus Granit-Xplus 54/160 (80 Euros).
A cheaper alternative would be the Abus Sinero for 40 Euros. Also good: Abus GranitPlus 51/150 (75 Euros). The only good folding lock: Abus Bordo Granit-Xplus for 120 Euros. The best armored cable lock was the satisfactory Abus Iven (45 Euros). Acceptable chain locks are the Abus tresor Chain for 33 Euros and the Master Lock 8391 Street Flexium for 21 Euros.

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