The 1340cc Harley Evo engine in the Harley-Davidson Bad Boy delivers grunt, fabulous noise (especially if you bin the stock silencers and fit a pair of open cans), lazy, US-style cruising and… not a lot else. Harley’s engineering hasn’t moved on much since the 60s. For fans, that’s the appeal of Harley-Davidson Bad Boy, for others it’s an anathama.