That’s right. I’m calling what I see is the latest trend in motorcycle racing. Two strokes are making a dramatic return to the world of racing. Two stroke racing engines have been banished from all forms of professional motorcycle racing for close to fifteen years now. Regarded as smelly and noisy, these engines have been blamed for everything from melting icecaps to the decline of western civilization. The ‘triumph’ of the modern, high rpm four stroke racing engine has been trumpeted loudly from manufacturers and politicians alike.


But there are two main problems: They aren’t illegal to build and use and racing enthusiasts as well as the racers themselves prefer them. The movement against the two stroke was entirely rooted in politics from the beginning. The two stroke retains the all of the advantages against the four stroke that it ever had. Namely low weight and high power output. Four strokes were given mathematical advantages in various racing rule books to give the impression that the two stroke had become obsolete.

But it seems the those impressions are wearing off. Race fans and riders alike are taking a fresh new look at the technology and demanding to bring them back. The power and agility of these bikes makes for great racing battles and their demanding power delivery challenges riders to improve themselves. The highly specialized nature of the two stroke motorcycle also creates a level of intrigue among enthusiasts.


This year the Isle of Man TT will allow the 250cc two stroke to compete in the Lightweight TT class and 580cc two strokes will be allowed in the Senior TT class. The 250's will compete against two cylinder four strokes up to 650cc and the 580cc will compete against Superbike class machines. Depending on who’s riding what, it would seem that the two strokes may well smoke their respective classes. I think that race organizers know this and they may well be priming the event for even greater two stroke participation in the future. The fans are excited.

Suter have gotten serious and are bringing 580cc to the IOM.


Off road racers, had long since returned to the two stroke as the oversized/overpowered four stroke rule standard didn’t offer any advantage in the off road format. The four stroke was seen for what it is...heavy. Although star off road champions like Mike Lafferty campaigned the four stroke for much of his career, it was only because they were being paid to do so. In Lafferty’s final season, he ran his old favorite, the 300cc two stroke. KTM continues to build their excellent line of two stroke MX and off road bikes as does Yamaha and some minor (but popular in off road circles) European manufacturers like Gas Gas. Yamaha even released a new, off road racing version of their YZ250, the YZ250X.



Yamaha’s newest model...a two stroke.


Many local MX organizations are allowing two strokes to race in four stroke classes due to increasing interest in the bikes themselves. And minicycle racing was spared from the four stroke invasion as the world financial crisis at the time made the transition too expensive. Honda developed their CRF150 four stroke in anticipation of rule changes. This bike is now the only four stroke mini and the other manufacturers have developed all new two stroke machines since then.

The world is also beginning to see motor racing from a more realistic perspective: That motor racing is not common to begin with. The environmental impact of all motor racing is negligible at best. Racing engines are exempt from environmental regulations for this reason anyway. An 18,000rpm MotoGP engine is a very ‘dirty’ engine, whether it has valves or not. Imposing environmental rules upon racing is causing a decline in interest in racing both on the elite level as well as the local level. And doing this for reasons that don’t otherwise promote racing is irresponsible to the sport.


Written by John Camara ExpressMoto Design