Kawasaki Square Four 2 Stroke Prototype

The Grand Prix Revolution HOLD!

030_0309_grandprix_18_z.jpg

Last year, the top class of Grand Prix road racing underwent a shakeup of epic dimensions when the GP rulebook was rewritten to give four-stroke racing motorcycles a nearly 100 percent displacement advantage over their two-stroke counterparts. This rule change made four-stroke motorcycles competitive in Grand Prix racing events for the first time since a very young Ozzy Osborne invented heavy metal with a new rock ‘n’ roll combo called Black Sabbath. This new rule completely changed the face of Grand Prix racing, and, as we are seeing in showrooms this year, it’s also changing the production motorcycles that we ride on the street.

A little history: Back in Ozzy’s early days, two-stroke motorcycles ruled the road and track. Two-strokes were light, cheap and faster than stink. Unfortunately, they did stink, spewing too many unburned hydrocarbons for the exhaust sniffers of the world to tolerate.

By the mid ’80s, two-stroke streetbikes had been outlawed on U.S. highways, though they continued to rule World Championship road racing until just last year.


As successful as two-strokes were on the racetrack, motorcycle manufacturers decided that it no longer made sense to spend millions upon millions of dollars developing two-stroke race bikes that have absolutely nothing in common with the four-stroke flyers sold on showroom floors. So manufacturers began lobbying for a rules change that would make more production-relevant four-strokes competitive in Grand Prix racing.

Because a 500cc two-stroke would hand a 500cc four-stroke its ass on a platter under any conceivable circumstance, the four-strokes were given a 490cc displacement advantage to equalize competition. The premier 500 GP class was renamed MotoGP, and the manufacturers nearly simultaneously abandoned all two-stroke engine development in favor of building new four-stroke prototypes. Two-stroke GP bikes, for all intents and purposes, are obsolete.

For a Super Streetbike rider like yourself, this is classified as a good thing; it means that the technology developed for the world’s most advanced race bikes can now trickle down to the bikes you drool over on the showroom floor. In a couple of cases, it already has. Here’s a breakdown of what’s on the GP track this year and why you should care.

What It Is: Honda RC211V

Last season, Honda’s V5-powered MotoGP racer made the rest of the field look silly. Sure, Yamaha won a race or two, but the Hondas were so dominant that these few wins almost seemed like Honda throwing Yamaha a bone because it was sick of seeing the competition roll over in submission. Damn did those Hondas ever sound good!

Why You Should Care:

Don’t expect to buy a road-going RCV anytime soon (though a V5 streetbike of some sort, probably something along the lines of the VFR, seems a sure thing). A street-legal RC211V would cost about as much as a new Porsche 911 Turbo, and it would still be a pale imitation of Valentino Rossi’s ride.

However, at least one piece of technology from this monster has already found its way to the street. The new CBR600RR features a Unit-Pro-Link rear suspension based on that of the RC211V. Other than the fact that the top of the shock is attached to the swingarm instead of the frame, the details of the suspension are too esoteric to be understood by a mouth-breathing liberal arts major like me.

Kawasaki Square Four 2 Stroke Prototype

What is clear is that it is very effective at keeping the front wheel on the pavement under acceleration. If ultimate lap times get you excited, you might think this is a good thing. If, on the other hand, wheelies are your thing, then you might not think this is so good.

What It Is: Yamaha YZR-M1

It’s hard to get a handle on Yamaha’s MotoGP entry because it was virtually a different bike in every race last year. Even Yamaha is confused, referring to the ’03 version alternately as the M1 and the M3, depending on what technician is talking. Whatever the company calls it, it is a surprisingly conventional motorcycle, a carbureted inline-four, just like the first-generation YZF-R1 streetbike.

Conventional or not, at least one version of the M-whatever was fast enough to beat the dominant Hondas last year.

Why You Should Care:

Recent versions of the M-bike have been spotted sporting dual rear shocks, sort of like a super-trick Harley-Davidson Sportster. Don’t look for dual-shock rear suspension on the next generation YZF-R1. More likely to make it to the street is Yamaha’s engine compression release system, which prevents engine braking, minimizing rear wheel hop when downshifting.

That’s great when you’re hauling down for a tight hairpin, but less great if you use engine braking to find your balance point while doing wheelies.

Kawasaki Square Four 2 Stroke Prototype
Kawasaki Square Four 2 Stroke Prototype
  • 2013 Kawasaki Vulcan 900 Custom
  • Kawasaki KR 750 Racer Classic Superbike
  • 1990 Kawasaki KDX 200, Classic Motor Cross, Renovation Tips.
  • 2008 Kawasaki Brute Force 650 Specs eHow
  • 2004 Kawasaki Mean Streak 1600 – Motorcycle USA