Bike locks

Choose a bike lock by how much time it costs a thief

No lock is unbreakable. What you’re buying is the time and noise it imposes on someone trying to take your bike — and the likelihood that they’ll choose another bike instead. Two practical implications: a lock’s weight and price tend to rise with the protection it offers, and the best lock is the one you’ll actually take with you.

Understanding security ratings

Each brand publishes its own scale, out of 10, out of 15 or on another scale. These ratings are not comparable between brands : a 7 from one brand does not equal a 7 from another. The only shared benchmarks are independent certifications — Sold Secure, ART or France’s FUB rating — which test locks under the same conditions. If your insurer or building management requires a particular level, these are the certifications it means.

Types of lock

• D-lock : the best security-to-weight ratio and the benchmark design. Its short shackle is a security feature in itself, leaving little room for a tool — but it means you need to find a nearby anchor point.
• Chain : flexible, it can be secured to almost anything and lets you secure the frame well. Heavy, it suits regular parking in the same place, where you can leave it behind.
• Folding or articulated lock : it folds into a compact block that fits in a bottle cage, while offering much more reach than a D-lock. A good compromise if you stop several times a day.
• Cable : useful only as an extra precaution, for securing a wheel or saddle. A cable on its own can be cut in seconds.
• Frame lock : it locks the rear wheel and immobilises the bike without securing it to anything. Handy for a two-minute stop, but never enough on its own.

How much to spend and how to lock your bike

A common rule of thumb is to spend around 10% of the bike’s value on a lock. How you secure your bike matters just as much as the lock itself: pass it around the frame frame and around a fixed anchor secured to the ground, not just around a wheel. Quick-release wheels and saddles need to be secured separately with a cable or anti-theft skewers. A well-positioned short D-lock is better than a heavy chain used badly.

Alarms and trackers

This is the category that’s changing. Alarms alarms are triggered by movement and sound loudly, which can scare a thief off; trackers, often compatible with smartphone location networks, can be hidden in the frame and help locate the bike after after a theft. Both work alongside a physical lock; neither replaces one.

To find out more: How to choose a bike lock

See also: Bike stands and storage · Car bike carriers · Bike lights