I had a chance to fondle the new Kawasaki Ninja 300 at the International Motorcycle Show in DC last week, and it certainly is a sharp looking little bike.

However, looks can be deceiving – if you check out the specs, Kawasaki’s new “lightweight” sportbike tips the scales at an embarrassing 379lbs.

Now, I’m not going to try and argue that the new Ninja’s design choices were bad from a commercial perspective. At the end of the day, Kawasaki is out to make money, and the Ninja 300 falls in an extremely competitive market segment. Conventional wisdom is that American motorcycle buyers only look at horsepower per dollar, so they built a bike with a hot motor and a low price tag. The Ninja blows it’s competition out of the water in terms of peak HP, and I’m sure it will sell briskly based on that fact alone. I would venture to guess that most of the target buyers won’t even bother to look at dry weight, because they don’t know enough to give a damn about it.

The end.

I just want to point out that, along with practically every sportbike on the market today, the little Ninja is a big fat pig of a motorcycle.

Some of my past posts (here and here) have featured custom builds that reduced weight substantially from the stock figures, and I think with the high stock output of modern engines, weight reduction is really the most effective modification you can make to a bike.

If you take a look at the world of racing to get a sense of what’s possible with current engineering, you will see that 250cc singles racing in the Moto 3 class weigh in at less than 150lbs. Admittedly, these bikes would be cramped for a grown adult (see below), don’t have any lights or DOT mandated junk, and the frames probably get checked for cracks after every race.

But with even the lightest road going 250 bikes coming in at more than double the weight, it’s clear that the current offerings are laughably overbuilt. Should you care?

Riding my 1989 VTR250 (at 310lb the lightest street bike I’ve owned) back to back with a modern FZ6 (420lbs), the weight difference has an obvious impact on handling. Even with 1980’s suspension and brakes, the VTR has effortless, telepathic, almost supernatural handling compared to the FZ. On the tight mid-speed stuff I like to ride, 110lbs is the difference between fighting to keep the bike on the road and being able to push it hard into the corners.

I can only imagine what losing another 100lbs would do to the ride since, apparently, nobody is willing to sell me such a bike.

The KTM Duke 390 down below, which comes in at a claimed 306lbs, is quite a bit closer to the goal than any of the Japanese offerings, but again, not even in the same league as the racers.

The best alternative anyone has come up with so far is a converted dirt bike, a so-called “super single” sportbike build. A Yamaha WR450 which cranks out almost 60hp and weights less than 250lbs stock could be built into a formidable road weapon if you could get a street title for it, but there is some serious re-engineering necessary to get the correct chassis geometry. Roland Sands Design has a beautiful conversion kit that you can buy for only $15,000, but until I find that huge pile of money I misplaced (or I can lay hands on a suitable donor bike for my own super single), the plan is to see how light I can go with the little VTR.

Stay tuned for build updates on that one. I’m currently staring at it and trying to decide what I should cut off first.

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