The most expensive, most intricate bike locks you can buy are really only guaranteeing that your bicycle's frame doesn't get stolen. Everything else, from your wheels to your seat, are fair game if not taken with you or somehow secured. But that 'somehow' could very well be these clever Sphyke miniature combination locks, which make it impossible for your ride to be disassembled without knowing the passcode.
Instead of using nuts, bolts and other components that require a proprietary — and easily losable — tool, the C3N system instead features a tiny combination lock that slides over the business end, preventing your bike's parts from being disassembled with any tools until removed. As long as you've got a decent memory, it seems like a rather brilliant way to ensure all of your bike is still there when you return to where you locked it up.
The C3N alternatives range in price from $US30 to $US80 depending on which type and how many replacement components you're buying. But if you live in an area where bike theft is the norm, it's probably cheaper than having to visit the bike shop every week — and definitely easier than carrying your bicycle wherever you go. [Sphyke via Gizmag]