First Test: 2011 Kawasaki KX450F – Dirt Rider Magazine

This multi-component shoulder cup for a BMW riding jacket is a single piece of metal, plastic and leather. Sounds impossible, but it’s real.

The poor guys in Kawasaki’s testing department. Since the introduction of the FI KX450F in 2009 the machine has won in WORCS, GNCC, OMA, National H&H, Supercross and National Motocross, but the bike has been overshadowed in magazine shootouts. Complaints of too fast, too stiff and other minor drawbacks torpedoed the (sometimes slightly too mean) mean green machines. Apparently the third time really is the charm, because Kawi hit the KX450F target dead center for 2011. On paper the changes look small, but on the track this is a whole new feeling. Clearly, the many varied championships and race wins prove the potential of the basic package, but in stock form the 2010 was stiff and harshly suspended for most riders. For a smaller number the power was overly enthusiastic and not at all suited to tight and technical tracks.Kawasaki kept it simple for 2011, starting with a new piston, a longer, larger-volume muffler, ECU changes and a shift mechanism upgraded with a larger internal roller and more shift spring tension. While still not exceptionally quiet, the ’11 has lost the raspy, blown-out sound. The KYB suspension already used prime components like the AOS fork with a slick DL coating on the lower legs and a shock with a 50mm piston, so the suspension changes were limited to revised damping settings front and rear and some anodized goodies to add a little zip to the look. Chassis upgrades were limited to stamped-steel head-stay plates that replaced machined-aluminum parts. The steel plates are said to add a more compliant chassis feel. As far as rider accommodations go, the seat foam is a bit firmer for longevity, and the seat cover has improved traction on the sides.It doesn’t take an extended test session to feel the suspension improvement. Your first laps will reveal the plush feel of the suspension. Bottoming resistance is still excellent, but the formerly hacky fork has become a super soaker on braking chop. The action is so supple and smooth on initial movement that front end traction is up and the bike feels better than ever in flat turns or when aiming for insubstantial ruts or minuscule berms.The shock demonstrates a much nicer action as well. It also has a plush feel with very little of the track surface reaching the rider. The rear of the bike is controlled under braking as well, but corner exits and acceleration are the most impressive facets of the shock’s performance. The rear settles under power, gets amazing traction and drives straight and true with no drama. All of the suspension adjustments we made were to settle the chassis. The initial testing was on the fast and rolling bumps of Racetown 395, and at times the bike felt a little loose and it was hard to trust the side traction. A couple of clicks stiffer at both ends and slightly slower rebound for the fork settled things down. For heavier pilots a quarter-turn of high-speed compression held the rear up without letting the bike feel harsh.Our feeling is that the initial violence of the 2010′s power compounded the harsh suspension feeling. For any little kick the engine broke traction and made things worse. For 2011, the power from way down in the rpm range is smooth and tractable with an easy roll-on. There is still plenty of energy there for most riders, and if you need more, turn the handle. The transition to mid is smoother but still builds strongly, and from there on up the engine revs smoothly and cleanly, like it has to work less to spin high rpm. Once revving, the acceleration is massive. The rear suspension doesn’t allow the rear to lose traction as easily, but the character of the power works with the suspension to keep things in hand. As a result you can think more about racing and less about controlling the bike.Getting over big jumps is as easy as ever with the smooth rush of middle and top rpm power, but now the bike is much more capable in rhythm sections that require precise timing. Riders looking for 2010-style boost should find it easily enough with FI tuning, but we’ll stick with the ’11.What the Kawasaki doesn’t have is the new-age chassis feel of the Yamaha and to a lesser extent the Honda CRF450R, that lighter feeling and shorter wheelbase sensation. That isn’t a bad thing, but an observation. The KX feels a bit long, stable and physically a little larger than some of the lightest and most flickable models. That does not make it any less effective on the track, but like any bike you play to its strengths. That should be easy with the suspension bumping up the front end traction. Overall the KX450F just works extremely well as a package, so in spite of minimal changes it has a better shot at a shootout win than ever.

Specifications:

2011 Kawasaki KX450F

MSRP: $8,149

Claimed weight (curb): 249.9 lb

Actual weight (tank full): 250 lb

Seat height: 37.4 in.

Seat-to-footpeg distance: 20.6 in.

Footpeg height: 16.8 in.

Ground clearance: 12.0 in.

Ground clearance: 12.0 in.

What’s hot!

Much smoother and easier-to-use power but still plenty of boost.

Suspension settings and spring rate choices that offer super-plush action.

Suspension changes make the bike feel lighter and turn in easier.

This bike hooks up very well!

Roomy riding position that suits tall riders without alienating compact ones.

Sound levels are down, and the exhaust note is less raucous.

What’s not!

With all the black on the bike it looks dirty quickly and shows wear.
It still isn’t the quietest machine on the track.

’11

Mini Comparison

2011 vs. 2010

Kawasaki’s 2010 and 2011 KX450Fs are separated by small but critical details that make a big and obvious difference on the track. The ’11′s muffler is larger, the piston and parts of the shift linkage are new, and so is the seat cover and FI mapping. For the ’11, the clutch is to shift, do starts and feed in the power. On the ’10 you use it to control violent wheelies. Controlling the ’10′s monster power was compounded by stiff, over-sprung and harsh suspension. If you have a ’10 KX450F expect the ’11 to have easier managed power and the plushest suspension in recent KX history. Pro hillclimbers should stick with a 2010. For anyone else, go 2011.

2011 vs. 2009

Honestly, the 2009 KX450F is a closer face-off with the 2011 than the 2010 is. All FI KX450Fs have had civil and dialed FI manners. In an on-track comparison, though, the ’11 has a more refined power delivery. It is more intuitive and less demanding. Even though the ’09 didn’t have the harshness of the ’10, the ’11′s suspension is vastly improved, and the fork is better than ever on braking bumps. That makes the bike happier to dive into flat turns or faint ruts than ever before. You could probably come pretty close to the ’11 if you remapped and revalved the ’09, changed the seat and added a quiet exhaust, but you wouldn’t have the shifting of the ’11 model.

2011 vs. 2008

For 2008, Kawasaki was in the final year of the carbureted KX450F and the first-generation aluminum chassis, and it was an extremely polished model. As great as the ’08 was, the shifting is not as crisp, clean and reliable as the ’11. Also, the current platform is slimmer, easier to move around on and sports a flatter, less sway-backed riding position. While the ’08 carbureted well, it won’t have the ’11′s instant response and what we call “wrist-to-rear-wheel connectivity.” You can make the ’08 very good, but it will be less comfortable, shift clunkier and never have the response of the FI years, and certainly be behind the excellent and low-vibration 2011.

Opinions

Kris Keefer

5’11″/160 lb /ProKawasaki’s little 2011 KX450F refinements add up big. The power now hits and has snap but instantly finds traction and pulls in a very friendly manner, yet is strong from the middle rpm on up. The overrev is not stellar, but a 450 shouldn’t be ridden wound out. I don’t ride at low rpm a lot on the track, but when you are in the bottom rpm range it is very controllable. I am in second and third gear most of the time, and the KX-F likes it. The suspension feels more balanced. The bike corners very well and it is easy to get into a tight rut without sacrificing stability. The shock squats coming out of ruts with acceleration bumps and stays planted and on the ground. Mucho traction! The fork was a little soft for me on hard landings and busy coming into a rough corner, but it is more manageable than last year. The controls and cockpit feel normal and easy to get used to. Kawasaki made a great big leap for 2011.Chris Denison

5’10″/155 lb/IntermediateI’ll take usable delivery over monster hit, which is why I haven’t been keen on the power-mad direction that modern 450s are headed. However, this Kawasaki just may make me like 450s. The 2011 rips, but the delivery is smoother and easier to handle than the 2010 version. Interestingly, the KX450F doesn’t like being short-shifted, but I soon learned the proper spot to keep the revs. From then on, the KX-F was a joy to ride. The Kawi still feels long and tall, though it seemed to lean over in turns easier and stay in ruts better than I expected. I still noticed a busy feeling on fast chop, though this is more of a slight jitteriness in steering than an overall instability issue. I love the ergonomics of this motorcycle, and I definitely feel like I would improve as a rider if I spend more time on the bike. Having spent a great deal of time on the 2011 KX250F, I can say that Kawasaki has one heck of a 2011 MX lineup.