Old school wheel lock on a bike in my backyard.
All Danish bikes have to have wheellocks for insurance purposes, but these days we use keys.
This one is a combination lock, which requires you to remember which metal buttons have to be pushed in.
The modern versions:![Wheel Lock (by [Zakkaliciousness])](http://static.flickr.com/1241/953778385_53b145cda5_m.jpg "Wheel Lock (by [Zakkaliciousness])")
![Click (by [Zakkaliciousness])](http://static.flickr.com/1432/954663484_5a2d47acfe_m.jpg "Click (by [Zakkaliciousness])")
