Choosing a bike lock

This article was published in 2015, in Newsletter 122.

For many Campaign members this may be old advice, but following my own observations around Cambridge and the results of our bicycle parking surveys it is apparent that there is a lack of knowledge or concern about suitable bicycle locks. I am continually surprised at the poor choice of locks by a significant number of Cambridge cyclists, which may be contributing to the rate of theft.

General advice is to choose a lock that is 10-20% of the value of your bicycle. However, if you are particularly attached to your bike you may want to spend a little more. You should get the highest ranked lock within your budget. The standard rating system seems to be Sold Secure and the best ranking is Gold.

The best security-for-weight option is usually a D-lock. For a chain to offer the same or more security it would need to be significantly heavier than a D-lock. This can be combined with a cable to help secure the wheels and provide more flexibility (see picture in previous article). It also helps to have two types of materials as this would require a potential thief to carry additional tools and take longer to break through the locks, thus reducing the appeal of stealing the bike.

Locks that should be avoided are those requiring a number combination or a poor quality key lock. These can usually be destroyed with a hammer. Thin plastic cables should also be avoided as they can be easily breached with wire or bolt cutters. Locks that are too big or not snug around the bike and anchor provide extra leverage for thieves to destroy the lock.

An expensive lock is of little use if it is not used correctly. The most important thing to remember is to ensure the lock passes through a closed section of the frame of the bike and that it is locked to something secure. Just as a bike lock can be breached, so can the fences, poles, scaffolding and the many other things that bikes are creatively locked to around Cambridge. Likewise, bikes are easily detached from wheels if that is all that is securely locked.

There are some intriguing new technologies emerging in the bicycle lock market. These include Bluetooth D-locks that are keyless and operated by a mobile phone, and cable locks from new materials purporting to be as strong as Gold Standard D-locks but a fraction of the weight. I’ve requested some samples of these new products and hope to have some reviews in a future edition of our newsletter.

Roxanne De Beaux