MD has been itching to test the machine Ryan Villopoto has taken to four consecutive supercross championships, the Kawasaki KX 450F.
The Kawasaki KX 450F has been dominating motocross shootouts for the last several years. There is good reason for this, as the stock bike has a great motor and excellent suspension. Our test rider Russ Somers typically campaigns a 2013 KX 450F, the first year with the launch control feature.
New for 2015 is a Showa SFF Air TAC fork with Triple Air Chamber, revised piston and ECU programming as well as an oversized 270 mm Braking front disc.
The new piston promises increased durability as well as a bump in compression (up to 12.8:1). Together with the revised ECU, Kawasaki claims the new bike has both a stronger mid-range and top end.
The fully re-programmable ECU is delivered with three separate “DFI Couplers” that can be snapped in in a matter of seconds to change the powerband for different riding conditions. With the optional software kit, you can create your own custom maps.
The 2015 model returns with the launch control feature that retards ignition timing in first and second to improve hook-up. This is activated with a push-button, and normal ignition mapping returns once you hit third gear.
The new Showa fork with Triple Air Chamber (TAC), according to Kawasaki, is derived directly from Villopoto’s race bike. With the supplied air pump, the rider can dial in an almost infinite number of changes in damping characteristics, with a better ability to handle small chop, while still resisting bottoming on big hits. A pneumatic spring substantially reduces weight and rebounds much more freely to help keep your tire in contact with the dirt. Three separate air chambers can be tuned individually, the source of this forks superb damping characteristics. The rear shock has revised valving this year, as well.
Other detail improvements include a lighter subframe (shared with the KX 250F) and lighter axles, both front and rear.
The KX 450F offers adjustable ergos, including handlebars that can be moved fore and aft a total of 35 mm, as well as foot pegs with dual-position mounting points.
The big KX has a great engine, and for 2015 we could feel the increased mid-range power. The bike still has huge bottom end, and revs out well. Short-shifting seems to be the fastest way around the track, however.
The biggest improvement is in the suspension. The new fork is fantastic. While, in the past, it was hard to find the right compromise between a setting that handled small chop and big hits, the new triple chamber design allowed us to dial out these problems, and set up the fork to handle both large and small hits in a relatively plush, controlled manner. The rear shock did its job, but it was the fork that really caught our attention.
The KX transmission was smooth and shifted under power without any problems. The motor is so strong that you could almost ride the typical motocross track in one gear using throttle and clutch to navigate the turns.
Handling also seems to be improved, although Kawasaki is not claiming any change in steering geometry for 2015. Perhaps the new fork takes the credit, but it seems to turn better than in years past, holding its line and railing through rutted turns without understeering. The KX feels light and nimble but also exhibited excellent straight-line stability through whoops and chop.
Our test rider is 6’3″ tall, and he had no problem adjusting the ergonomics of the KX 450F to work for him. The bike is slender and designed to allow the rider to move easily from front to rear.
We had a hard time finding something to criticize. The 2015 KX 450F is a monster in terms of power and suspension performance. It is hard to imagine any rider, particularly an amateur, wanting more horsepower and torque, and Kawasaki has done an excellent job of providing the chassis to compliment the engine.
The 2015 Kawasaki KX 450F retails for $8,699. For additional details and specifications, visit Kawasaki’s web site.
It sounds like this bike could stop a speeding locomotive, bullets would bounce off its chest, it could leap tall buildings, etc. I suppose this thing makes mid-high 50hp?
Is it too much to wish for a street legal adventure version, six speed transmission, 180 mile fuel range, good luggage capacity, under 350 lb full fuel tank curb weight, etc.?
I was most interested in the air-only triple chamber fork. Dividing stroke into three sections appears to solve the air-fork’s classic and well known down side of too high a rising rate: too soft in the first third of the stroke, too stiff in the last third of the stroke. Another “Why didn’t someone think of that before?” moments. Would be nice to see a cross section diagram of the fork. Is it patented or patent-pending?
“Is it too much to wish for a street legal adventure version, six speed transmission, 180 mile fuel range, good luggage capacity, under 350 lb full fuel tank curb weight, etc.?”
In a class of bike where pistons, connecting rods and cylinder heads are scheduled maintenance replacement parts and oil changes are called for every 15 hrs or so, would you really want one? A life of street use and moderate off-roading would increase those maintenance intervals by a good margin, surely, but I imagine it would still be very maintenance intensive to have an off-the-shelf race bike as a daily rider unless the engine were detuned a good bit.
Ah hell… I’d want one too.
Re: “Is it too much to wish for a street legal adventure version, six speed transmission, 180 mile fuel range, good luggage capacity, under 350 lb full fuel tank curb weight, etc.?”
Yes, it probably is. This engine makes mid-50hp but it does so in a way that probably isn’t very useful on the road, maintenance issues that Jeremy points out notwithstanding.
Making an MX-er into a versatile adventure bike without making it prohibitively expensive (remember, this is an $8.5k specialty piece already) will cost a lot of weight and likely component quality. The bike you want probably already exists, it just weighs 5-80lb more and falls short in a few of the desired metrics. Versys? FZ-07 (bet on an FJ version in the future)?
Not one comment about the bike or how it works so far?
Oh yeah, sorry, we got off onto another issue. 🙂
Damn Dirck, you sure can ride a dirt bike! Your pics are awesome! How did you lose so much weight?
And I won the “Your comment is awaiting moderation”! Damned Nuns, they control thought.
Damned is the filter word.
You thought Dirck portly?
Stout
That’s Russ Somers, our motocross test rider. When I was a bit younger I handled the off-road testing: http://www.motorcycledaily.com/2003/08/01august03_2004suzukimx/
it’ll be really interesting to get an appreciation from you on this bike, competition dirt bikes are a very refined product and I would like to know how much you think this kind of bikes have improved (if they have)