This may seem like an odd thing to do.... compare and contrast a 250cc sport bike and a 250cc motard, but I do get the occasional question of which bike I prefer. Having just over 3000 miles on both my 2009 Yamaha WR250X and my 2009 Kawasaki Ninja 250R, I think I'm able to offer a pretty good comparison of the two bikes.
Keep in mind that I do come from a motocross and off-road background, so I seem to prefer the more upright riding position of bikes like the WR250X. I'll admit that the lower riding position of the Ninja did take some getting used to.
Engine: (Winner: WR250X)
I've not done any 0-60 or 1/4 mile testing with either bike, but the WR250X definitely feels like it's a bit faster. Off the line, neither bike is a rocketship, but the WR250X seems to accelerate better and get up to speed quicker. I've done the typical exhaust, intake, and fuel mods to each bike, and it definitely improved the "fun factor" for both of them. From the dyno tests I've had done, my WR250X has better numbers than my Ninja...
WR250X... Max Power: 30.75, Max Torque: 18.79
Ninja 250R... Max Power: 28.44, Max Torque: 15.02
High Speed Riding: (Winner: WR250X)
Up front I'll say that I rarely get either bike above 70mph. I'm a back road bomber and never ride on the freeways, so my speeds are usually under 60-70mph. At those speeds, the best way I can describe the Ninja 250R is that "it feels like it needs another gear". The mods I did to the bike helped, but I'm constantly thinking I have another gear to shift to, when I don't. A simple gearing change would help here, but the way my Ninja is now, it "feels" wound out around 60mph even though I still have lots of RPM's to go before redline. The WR250X, on the other hand, is cruising along nicely in 6th gear at 60mph and the motor feels like it's just lumbering along at those speeds. I think both bikes top out just under 100mph, but the WR250X motor definitely "feels" better at higher speeds.
Low Speed Riding: (Winner: Ninja 250R)
What I'm talking about here is really slow riding, like when navigating through a parking lot. I'm not a big fan of the WR250X in these situations. The motor is very "jerky" at really slow speeds and on/off throttle is very abrupt. The mods I did to the bike helped a little, but the jerkiness is still there. When riding slowly through a parking lot on this bike, I normally pull the clutch in and coast as much as I can. The Ninja 250R, on the other hand, is very smooth and comfortable at slow speeds and on/off throttle is not nearly as abrupt as it is with the WR250X.
Aerodynamics: (Winner: Ninja 250R)
From an aerodynamic standpoint, the Ninja 250R is way better. The windshield, fairings and bodywork on the bike, along with the low riding position, definitely give it an edge over the WR250X, which has no windshield or much bodywork to speak of.
Handling: (Winner: Tie)
The low riding position and overall lower center of gravity of the Ninja 250R probably give it a slight edge when it comes to handling. But for a bike that is so tall, the WR250X really does handle nicely and I love riding it through the twisties. One advantage WR250X has is the stock Bridgestone BT090 tires, which are much better than the IRC's that came on my Ninja 250R. In fact, I replaced the stock Ninja tires with Bridgestone Battlax BT-003's after about 600 miles, and it definitely gave the bike better grip in the turns.
Versatility: (Winner: WR250X)
Here in Ohio, there are a lot of really rough roads. This is one area the WR250X shines. With 10+ inches of suspension travel, and off-road like ergonomics, I have absolutely no reseverations about riding the WR250X down just about any road because I know it can handle pretty much anything. With the Ninja 250R though, I try and stick to nicely paved roads, otherwise the bike, with it's short/stiff suspension, really beats me up.
Another nice thing about the WR250X is that you can buy yourself a set of dirt wheels/tires and you have a very capable off-road/trail bike. After all, this bike is very similar to the more off-road worthy WR250R.
Seat Height: (Winner: Ninja 250R)
I'm 5'9" tall with a 32" inseam. I love the low seat height on the Ninja 250R. Pulling up to stop lights and stop signs is a breeze on this bike. With the WR250X, it's a little bit more of a challenge since I'm on my tip toes whenever I stop. This did take some getting used to when I first got the bike, and I still have to pay more attention when stopping. I added a Spiral Step Seat to the WR250X, which lowered the seat height about an inch, but the Ninja 250R still gets the edge here.
Ease Of Maintenance: (Winner: WR250X)
I've done an oil/filter change on both bikes, and they are both pretty simple. I do like how the WR250X sits up higher, and the taller ground clearance makes it easier to get to the oil drain bolt. The oil filter is also easier to get to on the WR250X since it's on the side of the engine, whereas the oil filter on the Ninja 250R is underneath next to the oil drain plug. Since the WR250X doesn't have any bodywork covering the engine, it just makes getting to everything a lot easier. I also like the fact that I can put the WR250X up on a stand like this, which lifts both wheels off the ground. With a sport bike like the Ninja 250R, to get both wheels in the air, you'd need a front AND rear stand.
Fuel Mileage/Range: (Winner: Ninja 250R)
I don't know the exact fuel mileage I'm getting on either bike since I've not really paid much attention, but I'm guessing it's pretty close between the two. I do know the last round of mods (exhaust,filter,fuel controller) I did on the WR250X seemed to hurt gas mileage a little bit. The big winner here is the Ninja 250R, with its larger 4.8 gallon fuel tank. You can carry more than twice as much fuel in the Ninja as you can in the small 2 gallon tank on the WR250X. This means quite a bit more range with the Ninja. I'm actually looking into buying a larger aftermarket tank for my WR250X because I really hate having to stop for fuel on pretty much every ride.
Comfort: (Winner: Ninja 250R)
For short rides under 100 miles, I would say that comfort is about the same on both bikes. When you start going further than 100 miles, the Ninja 250R is more comfortable. I've done as much as 200 miles on the Ninja at one time, and the seat was very comfortable and didn't bother me at all. However, with the WR250X, the seat starts to get uncomfortable after about 100 miles. I seem to be getting more used to it, but it's still not nearly as comfortable as the Ninja.
Looks: (Winner: Tie)
Looks are a very subjective thing. Kawasaki did a great job with the Ninja 250R. It's a really nice looking bike, and looks very similar to the bigger Kawasaki sport bikes. The WR250X is also a good looking bike, but around here nobody seems to know what it is. I get alot of questions at gas stations about the WR250X... people asking me what kind of bike it is, or whether that "dirt bike" is really street legal. It's kinda neat riding a bike like the WR250X because it doesn't look like many other bikes, whereas the Ninja 250R looks like a lot of the other sport bikes so common on the road.
Technology: (Winner: WR250X)
The WR250X features fuel-injection, titanium intake valves, an aluminum frame and swingarm, forged aluminum lower triple clamp, aluminum steering stem, plug-top ignition coils and an exhaust valve. The Ninja 250R is a bit more low tech, having a carburetor and a steel frame. The WR250X definitely feels like a more modern bike.
Price: (Winner: Ninja 250R)
The MSRP on my 2009 Ninja 250R (special edition) was $4099 and the MSRP on my 2009 WR250X was $6,190. That is basically a $2000 difference in price, however, in my experience buying both bikes (which I bought at the same dealership), they were more willing to deal on the WR250X. I bought my Ninja 250R in April of 2010 and the dealer was not really willing to deal much on the bike, claiming that they sell so well that they didn't have to. I was only able to get $200 off the MSRP. I bought my WR250X two months later, and they already had the bike marked down from $6190 to $5100, and I was able to get them to drop another $200 from there. So, in the end, the WR250X only cost me $1000 more. If you consider MSRP, the Ninja 250R is definitely the better buy, but for me, only having to pay $1000 more for the WR250X, I think it was the better deal.
Which bike do I prefer? Early on I seemed to change my mind once a week on which bike I preferred. They are both a lot of fun to ride and each have their advantages/disadvantages. After putting around 3000 miles on each bike, I think I prefer riding the WR250X. In fact, towards the end of last summer, I seemed to be riding my WR250X quite a bit more than the Ninja. I come from a motocross racing background, so the upright "dirt bike style" riding position of the WR250X suits me better than the lower riding position of the Ninja. I also like the versatility of the WR250X.... I feel like I can ride the bike just about anywhere, on pretty much any type of road surface, and it will handle it with flying colors. And I won't lie... I like riding a bike like the WR250X that is so unique looking. Around here, I rarely see any other motards on the road, whereas sport bikes like the Ninja are all over the place.
All that being said, I really don't understand why bikes like the WR250X (and WR250R) don't sell better. I've heard that the Ninja 250R is Kawasaki's best selling bike, but in contrast, it doesn't seem like Yamaha sells a lot of WR250X's. Maybe it's because the Ninja looks like it's faster 600cc sport bike sibblings, and let's face it, for many people, motorcycling is as much about image as it is about riding.
For me though, if I had to choose between these two bikes and could only have one of them in the garage, I would take the Yamaha WR250X. Once I add a larger fuel tank, and get rid of that jerky slow speed throttle response, it'll be the perfect bike (or close to it).