Europe's biggest gathering of custommade bicycles and their colourful owners gathered in Amsterdam's Westerpark on Sunday (July 30), under the name of FBI - Choppernation. Organizer and bike-lover Raalf van Housten explained to Reuters: "FBI stands for Fundamentalist Bikers Incorporated. We just love our bikes and we love to ride them." Custom-made bicycles are also called low-riders, choppers, dragbikes or pimpbikes. Every one of them is unique, if it is not designed then it is certainly built and painted by the proud owner. But the creations are made for cruising not for racing. That's why Dragrace may be the funniest part of fifth annual Choppernation gathering. Bikers travelled from around all over the world -- including Canada, US, New Zealand and most of Europe -- to show off their wheels. It is not an event for the feint-hearted. "You own your own bike and you've got a unique bike to ride. That's maybe the most important thing - you get recognized by your bike!" said Raalf van Housten. This year, even a dream-bike exposition is organised as a part of FBI, curated by Abner Preis. Some artists have properly built, choppered and pimped their dream-bike, while others have painted it, drawn it, or even carved the bicycle in a watermelon. The first FBI cruise took place in October 2002 and since then it's a yearly event. The gathering continues on Sunday with more racing, more cruising and more beer.