In an era when emissions regulations are becoming over stricter, it's hard not to reach the conclusion we're at a turning point in motorcycle development.
But before we all accept a plug-in future there's still a bit of life left in the internal combustion engine, and manufacturers are getting extreme in their efforts to make it cooler than ever before. We are now seeing unprecedented levels of performance and economy, jostled along by international rules ensuring that exhaust emissions are cleaner and quieter than in previous generations.
In Europe, Euro-4 emissions rules will be phased in during 2016, with even tougher Euro-5 standards due to arrive in 2020, and they represent a challenge when it comes to packaging the increasingly bulky emissions-reduction kit, particularly into exhausts of the next generation of motorcycles. You only need to glance back a decade to see how much the size of stock exhaust systems has already grown – compare a 2006 motorcycle with the latest models for instance. Further growth will be hard to stomach, both in terms of aesthetics and engineering. Size and weight are the greatest enemies of motorcycle designers and engineers.