Bike in toast rack with D-lock
An expensive cycle shouldn't be locked with a poor-quality lock. While no lock is 100% secure against all criminals, hardened steel D-locks are generally the most effective deterrent.

A variety of cycle alarms have recently appeared on the market, and can provide an extra deterrent to thieves.

Helps the Police to identify stolen cycles and trace their owners. Postcoding is done on Sunday mornings, 10.00 till 12.00, at the Police Station off Southfields Road. The local press often has details of occasional postcoding sessions at other locations.
There is also a variety of commercial registration schemes in which cycles can be fitted with a unique identifier.

Can seem expensive, but worthwhile if the worst happens.