2017 Kawasaki KX250F: First Ride Impression
By Scott Hoffman and Dustin Hoffman (no relation)
Photos: Scott Hoffman
The 250F class has been so competitive the last few years and the Blue Crew has grabbed some of the limelight as of late when talking about off-the-showroom-floor production bikes. Kawasaki, who has a long history of winning titles in the 250F since slapping valves in a 250, has racked up 16 titles along the way. For 2017, Kawasaki has launched an all-new 250F that they call a lighter, faster, and better-handling motorcycle. Kawasaki is serious about this bike and launched via a worldwide media event at Zaca Station north of Santa Barbara. In addition to some of the frills, here is the skinny on the bike.
The list of “what’s new and changed” is vast and long, meaning very little has been carried over from the previous model. The 250F does share some components with the 450F chassis but that list is short. Obviously the look of the bike is similar to the 450F, yet the 250 frame is different. The new new 250f features a one-piece forged downtube which is melded with a cast section before being joined a with narrower extruded side spars. The frame has also made it possible to flatten out the front of the seat and lower the fuel tank. The rear of the frame is also revised with a new mounting position for the linkage, a more progressive link ratio, and a revised lighter and race team-inspired shock spring. The rear is joined with a new swingarm that is lighter with thinner sidewalls and thicker top and bottom walls, which claims to offer more torsional stiffness and improve traction. Up front, the triple clamp has been revised and is a shared part with the 450F, which is thicker and offers more clamping surface. The 250 runs the Showa SFF spring fork, also updated for 2017.
The engine was also not left alone and we are seeing several friction-reducing features to boost the performance. The cylinder head is new with a steeper downdraft intake and revised fuel injector. The cylinder is also offset and the cylinder angle has been altered 7 degrees. The crank has also gone away from the traditional needle bearing for the lower rod to a journal style or flat bearing for reduced friction. This is a similar technology you see in most automobiles and KTM also uses this style of lower-end bearing.
The head is new and the combustion chamber now goes through a machine process for more accuracy and precise airflow. The piston is 6 grams lighter, the cylinder has a Plateau Honing process for a smoother surface, and the flywheel is also lighter for 2017. Kawasaki’s also going to offer two optional flywheels, one even lighter and one heavier by .5 kg/cm for further power tuning.
There are more minor changes such as going with the Dunlop MX3s tires, slightly lowered rear muffler, new airbox design and the graphics are molded into the plastic. Making a return appearance is the launch control, adjustable map couplers, adjustable handlebar and footpeg position, and easy-to-tune ignition and fuel mapping with Kawasaki’s handheld tuner.
The changes have been geared to offer a thinner-feeling chassis and an overall lighter machine with a claimed curb weight (all fluids and 90% fuel) of 233.6 pounds, which is a savings of 3.75 over 2016.
We spent one day on the bike up at Zaca Station, which was ripped but not too deep and still provided a nice cushion of dirt on top for most of the day. The track never developed any real rough sections because there were only a dozen or so bikes on the track at any given time.
First off the chassis feels very light but still retains much of that traditional Kawasaki straight-line stability. For our test rider, we did slight adjustments to the handlebar but never felt the need to adjust the position of the bar mount forward or back, nor the footpegs, although they are both adjustable. The flatter and slightly narrower seat and shrouds give the new KX a lighter feel while riding, not to mention the slight weight saving overall. The new chassis feels more up to date with the light, slim, and quick-handling generation.
On the track the bike is balanced but we did chase the front-end feeling around for part of the day. We tested several rear shock sag settings from 104-107mm. Those changes alone were very noticeable on the track and how it loaded the front end. There is no magic number; it really depends on the rider and how they ride the bike. We found settings that actually made the push and vague feeling worse at one point, but in the end we finally found a setting that worked. The combo of settings and slowing down the rebound on the fork and messing with tire pressures resolved most of the issues. Zaca is a unique track that gets loose on top and hard below so we will need to test at different tracks to give you more feedback.
Other than the above tuning issues, the chassis works very well and does not have any bad habits and is very stable and complements the power delivery. The new 17s definitely have a lighter feeling and changing direction is easier than before. The suspension was very close with the factory settings for our 150-pound test rider, which is right there in the target zone. The fork is the SFF spring fork and is very tunable and we were able to work with the fork and utilized clickers as well and fork spring preload. The front and rear was very balanced and tracks well, although the course remained fairly smooth all day. What we did discover is re-checking tire pressure is important. It was hot that day and we realized that from the morning to mid-day the pressures did increase by a pound. Re-adjusting the pressure was a noticeable change and made tuning for the rest of the day more accurate. We re-set the tires to 13 pounds front and rear, for example.
Yeah, we know you want to know about the performance. The new KX engine is very free revving but it does not spike and run through its power curve too fast, at least at Zaca, which is fairly thick in places when watered and ripped. Like most 250Fs, the bulk of its ponies are in the upper range. The KX comes on strong in the mid and seems to pull very well into the top and rev out very well. The bottom is not robust so being in the right gear is required to yank itself out of deep corners without having to abuse the clutch. Zaca has several power-robbing hills and our KX never felt underpowered for the most part. Gear spacing is very matched to the power and there were no real gaps. Shifting is smooth with or without using the clutch.
At Zaca our test rider actually preferred the performance traits of the white or clear aggressive coupler. And these settings can be further adjusted with the Kawasaki tuner if desired. We did not have enough time to jump into any custom maps but we will in the near future. The more aggressive map gave the bike the bottom chug that is slightly lacking and our rider was able to rail turns in a gear higher in several places and carry more speed up jump faces. Yet there is a slight tradeoff, although it comes on lower and harder in the middle, you do give up a little on top because it builds the power faster and flattens out on top slightly. Our rider actually over-jumped several sections on the first few laps with this setting because the bike just carried more speed.
250Fs have come so far in a short period. Stock 250Fs probably put out more power now than full factory bikes did less than a decade ago.
With one day on the bike, the 2017 KX250F is a better motorcycle than the previous generation. The new bike is slimmer and lighter feeling on the track and the power is very free revving and more potent than older versions. We need more seat time to give extensive feedback yet there were no real issues other than having to tune out a front end push early in the day. The bike feels balanced and refined with the latest generation KXF. The KX250F is for sure in the game and we will spend more time on it at several different tracks to bring you a complete test in the near future.