It's kind of ironic that while many cyclists ride lightweight bikes, they still carry heavy-duty U-locks that weigh several pounds. In most cases, however, lighter cable locks can easily be defeated with a set of bolt cutters. That's why Prof. Neil Barron, a former aeronautical engineer, has created the Litelok. It's light and flexible like a cable lock, but reportedly stands up to over five minutes of attack from tools such as bolt cutters, jacks and hack saws.
The Litelok's strap is made from a composite called Boaflexicore, which consists of multiple layers of unspecified lightweight materials. The steel inline locking mechanism was developed by UK manufacturer Henry Squire and Sons Ltd, and locks shut without the need for a key.
The whole thing weighs less than 1 kg (2.2 lb). By contrast, the commonly-used Kryptonite Evolution U-lock tips the scales at 1.7 kg (3.75 lb).
A couple of straps are included for carrying the Litelok on one's bike, as is a strap-equipped pouch. If it looks like a single 29-inch (736-mm) lock might be too short to meet a user's needs, they can order a package in which two locks can be linked together end-to-end, and unlocked using the same single key.
Barron is currently raising production funds for the Litelok, on Kickstarter. A pledge of £70 (about US$103) will currently get you one, when and if they're ready to go.