The Kryptonite lock is an Ingersoll Rand-owned brand of bicycle lock for securing a bicycle to a pole or other fixture, when the owner wants to leave the bicycle in a public place. The basic design, made of hardened steel of circular cross section bent into a U-shape with a removable crossbar, has been emulated by numerous other manufacturers, and adapted with variations in size and shape for other applications, such as locking motorcycles.
The product was named after kryptonite, the fictitious substance that can thwart the powerful comic-book hero Superman. The name is used under a limited trademark agreement with DC Comics dating back to 1983.[1]
Contents |
The Kryptonite lock was developed in 1972. Before then, the only comparable security available was from a chain, which could weigh almost as much as the bicycle. (A common humorous observation in bicycle magazines at the time was that the total weight of a bicycle plus chain was constant regardless of cost, since owners of more expensive, lighter bicycles would buy heavier, more secure chains.) In the early 1970s the only proven method to secure one's bicycle was by the use of case hardened security chain with hexagonal links, but some cyclists were making the mistake of using inexpensive chains or cables that could be breached by thieves using commonly available tools. Indeed, local hardware stores would often sell inexpensive chain cut to length using simple bolt cutters. The first Kryptonite lock model was made of sheet metal cut and bent to shape, but the company soon went to the now universal circular cross section.
In an early test of the Kryptonite lock, a bicycle was locked to a signpost in Greenwich Village in New York City for thirty days. Thieves stripped the bicycle of every part that could be removed, but the lock resisted all attempts to break it.[2] The innovative U-shaped design of the Kryptonite lock was subsequently adopted by several other manufacturers, with varying degrees of security. U-locks can often be seen holding naked rusty bicycle frames without pedals, gears, or wheels to bicycle racks.
A limitation of the Kryptonite lock is that it is heavy and bulky. Most (apart from the Fahgettaboudit Mini and M18 series) are provided with a plastic carrying bracket that will not fit all frames, nor will it retain the lock when riding over rough surfaces, making transport of this large lock difficult. For that reason many commuter cyclists leave this lock attached to a bicycle rack at their destination, rather than carry it back and forth every trip.
In 2005, Kryptonite changed their locks from a tubular-key to an I-key, which stopped the ability of a BIC pen or other cylinder shaped object from defeating the locking system.[3]
Until 2004, Kryptonite locks used the tubular pin tumbler locking mechanism. Videos circulating on the Internet demonstrated that some tubular pin tumbler locks of the diameter used on Kryptonite locks could be easily opened with the shaft of an inexpensive Bic ballpoint pen of matching diameter.[4][5][6][7][8][9]
The three most common methods that can be used to break open Kryptonite locks are the use of a small hydraulic bottle jack to spring open the lock, an angle grinder to cut the U-Lock, or a portable plasma cutting-torch to melt away enough of the U-Lock or chain to allow the frame or securing apparatus to pass through the gap.