The bicycles referred to in this guide are nonmotorized pedal cycles. Bicycle theft refers not only to the theft of a complete bike, but also the theft of bicycle components and accessories such as lights, seats, and wheels. Bicycle theft is typically a low police priority, with its prevalence and impact often overlooked because incidents are considered on a case-by-case basis rather than being analyzed at the aggregate level. At the aggregate level, bicycle theft has harmful economic and societal effects that warrant greater police attention. Since bicycles have become increasingly popular as a healthier and environmentally friendly mode of transport, their ownership and safe use is a positive development in public safety. Several studies have suggested that fear of cycle theft may discourage bicycle ownership and use, and many victims of bicycle theft do not buy a replacement; therefore, combating bicycle theft is an important part of increasing the use of bicycles as an important means of transportation and exercise. In providing an overview of the problem, this guide focuses on the collection of bicycle-theft data, clearance rates for incidents, offender profiles, recovery rates for stolen bicycles, theft locations, repeat victimization, offender techniques, and factors that contribute to bicycle theft. A local analysis of the problem involves determining the extent of bicycle theft, locations and times, offender characteristics, victim characteristics, and the nature and effectiveness of current responses. A review of responses to bicycle theft considers locks and locking practices, parking facilities for bikes, registration and recovery, and offender detection. 80 notes, 63 references, and appended summary of responses to bicycle theft and types of locks