The best thing about the Single Speed European Championships (well really the best thing about any single speed mountain bike event) is the sense of fun.    Of course, fun is a relative term. Fun means a little something different to everyone, and this event and events like this, take that into account.   For instance: there were some dudes there for whom fun was to jump on their plasticized carbon 29er and ride as fast as they could, not even stopping at the beer tent at the halfway point, racing to the end with fury on their faces and…