Adam Booth | May 12, 2017
We ride all of KTM’s latest and greatest EXC-F dual-sport bikes.
It’s a great time to be a fan of dual-sporting, especially if your idea of “dual” tends to lean more toward the dirt than street. For years, the manufacturers have seemed to define “dual-sport” as a motorcycle meant to be ridden on the street that could be ridden in the dirt – rather than the other way around, which is how so many of us want it. Unfortunately, the Japanese manufacturers still build them mainly for the street. But KTM (as did Husqvarna) rebuked that idea a long time ago by offering what many believe are the first true off-road dual-sport bikes, and now KTM has taken the dirt in dual-sport another step further after introducing its latest range of dual-sport bikes: the 2017 250, 350 and 500 EXC-Fs. The 250 is a new member of the family.
KTM’s new EXC-Fs are perhaps more dirt-worthy than ever. They are true hard-core dirt bikes that just so happen to have a metal license plate on the back. In fact, they are so dirty that the company decided not to even bother offering a “Green Stickie” dirt bike—their “W” models—anymore. Since the W’s were so close to being street-legal anyway, they decided to go all the way and just make these. So KTM now offers just “race” off-road bikes (XCs) and street-legal off-road/enduro bikes (EXCs). Pretty simple; not to mention, brilliant.
We recently got the chance to spend the day riding and comparing all three of KTM’s new EXCs side-by-side-by-side, while logging 115 miles over asphalt, dirt roads and single track along the way. We then spent another full week and an additional 500 miles aboard the 500 EXC-F. (KTM offers a 450 EXC-F, but as a Six Days Edition, which has more bells and whistles and a larger price tag.) We rode the three EXCs exactly as you would get them off the showroom floor; no mods, nothing. Though we did take advantage of any available adjustments that each one offers.
Click here to read this in the Cycle News Digital Edition Magazine.
Story and Photography by Adam Booth
What Makes Them Tick
Put the 2016 KTM EXCs behind you, because the 2017 EXC-F models are all-new motorcycles and have very little in common with last year’s models. All the 2017 EXC models are built on the same basic platform, outside of engine size and design. The 2017 engines are nearly identical to the 2016 SX (motocross) models, which means they are much lighter, more compact and produce more power than the previous EXC engines. All three engines use a Keihin 42mm throttle body; the SX-F motocross models use a 44mm throttle body. To help meet strict EPA noise regulations, the airbox design is a first of its kind, in that KTM installed noise-suppressing reed valves placed in the intake tract between the air filter and the throttle body. Picture the reed valves you know from a two-stroke and that’s what is in the tract. KTM found that the reeds not only substantially reduced intake noise like they were supposed to, but also, to their surprise, improved engine performance! They found that the reeds actually improved torque.
The entire emissions system in the EXCs is well-designed and out of sight. Even the evaporative canister is hidden in the frame’s downtube.
The revised chassis provides more torsional stiffness and less longitudinal stiffness, helping to absorb bumps without twisting. KTM shaved nearly a pound of weight from the new frame. As an added bonus, the new frames are fitted with threaded inserts for a KTM accessory skid plate.
For 2017, the EXC line received the new WP Xplor split fork and the Xplor PDS shock. The fork is still an open-cartridge design style with adjustment for compression on one side and rebound adjustment on the other, with easy-to-reach dials on top of the fork legs. The fork has also been designed to better resist bottoming and is about a half-pound lighter.
The new and much smaller Xplor PDS shock is 1.3 pounds lighter than the previous shock and is about the size of a shock found on an 85cc motocross bike.
One of KTM’s goals was to lower the overall seat height of the EXCs for 2017 and they were successful, losing 20mm of overall height with changes to the suspension and seat. The Xplor fork is shorter than last year’s fork and has about 10mm less travel. The Xplor shock, while actually longer than last year’s shock, is positioned differently, helping to drop the back end of the bike. The EXC seat is lower and slightly wider when compared to the SX-F and XC-F seats, but still uses the same base and is interchangeable with the other models.
Take the mirrors and blinkers off and the EXCs could easily be mistaken for an XC or an SX. All the 2017 KTM models share the same styling, which means the new EXCs are the most aggressive dual-sports we’ve ever seen.
The Continental tire choice might seem silly for such a dirt-worthy machine, but again, it all comes down to passing EPA regulations. The TKC 80 tire cuts down on the noise level for the drive-by sound testing, helping the EXCs earn the license plate that hangs off the back fender. Most riders will no doubt quickly change the street-orientated tires for more aggressive DOT knobbies.
After twisting the throttle on all three bikes for an entire day and logging over 100 miles, we’ll tell you right now that these bike are brilliant. KTM has owned the hardcore dual-sport market for a number of years, but there is always room for improvement and these bikes are not leaving much of that anymore. The previous generation of EXCs (350 EXC and 500 EXC) ran fairly well in stock condition but still suffered from extremely lean mapping and popping on decel. Those issues are gone for 2017 and in bone-stock trim all three of the EXC-Fs run extremely well. We rode the three bikes from sea level up to 4000 feet without any issues.
500 EXC-F
The 2017 500 EXC-F is an all-around great bike that runs amazingly well, even with all of the emissions equipment and sound restrictions in place. Previous-generation 500 EXCs have had lean mapping that made the bike prone to stalling and backfiring. These aren’t issues anymore with the new-generation 500 EXC-F; instead, throttling is spot-on, clean and consistent.
The 500 EXC-F engine, however, isn’t for the faint of heart. It provides a ton of power and it does it immediately off idle. The response from the 42mm throttle body is instantaneous, and if you aren’t smooth with the throttle, the 500 EXC-F can feel very jerky and jumpy when transitioning from deceleration to acceleration. Modulating rear-wheel traction in tight conditions requires a very calculated throttle hand in combination with smooth clutch work. A Rekluse auto clutch is an addition that would make rocky and technical riding pure bliss on the 500 EXC-F. As the power gets into the middle and higher revs, it’s smooth and plentiful, but not as arm-stretching as the KTM competition (XC) models. That’s fine, this isn’t a race bike and that is quite clear by the ultra-quiet nature of the bike. Its stealth-like exhaust note is deceiving. Trust us, this engine, in stock trim, offers up plenty of wheelie power!
The Xplor suspension is ultra-comfortable on the 500 EXC-F. For riders over 180 pounds, it borders on too plush, especially if they are aggressive. In tighter single-track and technical riding, it works well for a wide range of weights and abilities, providing great traction and comfort.
The new-generation EXC-Fs have a lower seat height that enhances the overall feel and comfort of the better-balanced suspension. In the past, the 500 EXC suffered from overly soft forks and excessive diving was an issue. That is thankfully not a concern anymore because of stiffer springs and damping changes in the 500’s forks, and this also contributes to the bike’s improved balance. Even so, the 500 EXC-F isn’t a whoop-smashing bike in stock form, the suspension works well for what it was designed for—trail riding.
Out on the pavement and down the dirt roads, the 500 is king and the most comfortable to ride thanks to an abundance of torque and just plain excellent overall power. The stock gearing works great for off-road and still provides a comfortable ride at 70 mph. The 250 EXC-F, believe it or not, was our next favorite on the road thanks to taller gearing and a less vibration. The 350 EXC-F’s final drive is geared significantly different from the 500 and the 250 and revs out earlier. A simple rear-sprocket swap will fix that if needed.
After a few hundred miles and some complaints about comfort of the stock EXC seat, we tried an SX-F seat, which is a bit taller with thicker padding—it worked out well. We happily traded a little more seat height for comfort.
Another thing you can do to improve comfort is to balance the wheels. It 100-percent changes the character—all for the good—of the bike above 40 mph on the street and in the dirt. We balanced the wheels on the 500 EXC-F after one day of 100 miles and couldn’t believe we were riding the same bike the next day. The chassis was more settled and the engine felt like it had less vibration. Even if you change out the TKC 80 tires, balance the wheels! We comfortably cruised down the freeway at 70 mph on the 500 EXC-F with the balanced wheels, even running 90 mph for extended periods.
At 258 pounds with a full fuel tank, emissions equipment, turn signals and a license plate, the 500 EXC is still lighter than any of the 450cc four-stroke off-road bikes from Japan. It ranges from 6-15 pounds lighter than the CRF450RX, YZ450FX, WR450, CRF450X and RMX450Z.
The bottom line is quite clear; the KTM 500 EXC-F, even with all its street-legal equipment and emissions restrictions, is lighter and better-performing than any other green sticker 450cc off-road bike on the market. (You can read our Green Sticker shootout here ) Had it been included, the 500 EXC-F most likely would have been top dog. And, afterward, we could have ridden it home!
350 EXC-F
Among the three EXC-F models we tested, the 350 EXC-F was a favorite, and for good reason. It provides plenty of power, and the smaller piston, combined with less torque, makes the bike feel quite a bit lighter and more manageable than the 500 EXC-F, proving that engine power alone has a huge affect on how a bike handles. The 350 EXC-F tips the scales just four pounds less than the 500 EXC-F, weighing in at 254 pounds (with a full tank of gas, and keep in mind that all three bikes have the same fuel tank), but when in motion, the 350 feels way lighter.
Like the motocross version, the dual overhead cam 350 EXC-F engine is happy to be ridden however you choose. It provides smooth torque off idle, starts to really come to life through the middle, and then revs incredibly high. This engine is a great mix between the ultra torque of the 500 and high-revving 250. The nice trait about the 350 EXC-F engine is the smoothness off idle; it’s not as abrupt as the 500 EXC-F and doesn’t require as much precision to control wheel spin in technical or slippery conditions.
The 350 and 250 share the same basic architecture when it comes to the engines, so visually they look identical. Internally, though, the six-speed transmissions have different ratios, and the final gearing to the rear wheel is different, adding up to a big difference in feel between the two.
The suspension on the 350 EXC-F (and 250 EXC-F) can only be defined as squishy! This is a very plush and comfortable set up for true off-road trail riding. The Xplor suspension is very similar for all three bikes; in fact, the 350 and 250 share the same spring rates and valving. The 500 uses one-rate stiffer springs, front and back, with very slight valving differences to compensate for its slightly heavier weight and the heavier riders that KTM figured will most likely buy the 500 over the 350 and 250. We ended up increasing the compression damping on the 350’s and 250’s forks 3-5 clicks, depending on the trail, with good results. A little more damping helped reduce fork dive down hills and braking into corners. In the nastiest of trails, testers preferred the plush 350 and 250 suspension, but as soon as the speeds increased, the 500’s suspension was liked most. Again, it depends on your weight and riding style. If you are light and not that aggressive, the 350/250 suspension will be great. If you are bigger and like to ride harder, a spring-rate change will probably be in your future.
While the ergos are exactly the same among the three bikes, the 350 feels smaller. It’s just a head-trip thing because there is no difference besides the engines. It just goes to show that rotating mass inside the engine plays a huge role in perception of the size of the bike.
We really only have one fairly trivial complaint with the 350 EXC-F: The final gearing tops out way too quickly on the road. KTM chose gearing that would best help with noise on the drive-by noise testing. Going down a few teeth on the rear sprocket is an easy fix, but don’t worry, the 350 EXC-F has enough power to pull the taller gearing off-road. If you don’t plan on extended periods of 65 mph on the road, the stock gearing is great off-road.
KTM 250 EXC-F
There isn’t another 250cc dual-sport bike on the market that can even start to compare to the 2017 KTM 250 EXC-F. No other manufacturer produces a 250 dual-sport based heavily on a 250F motocross bike like this. KTM’s new 250 EXC-F is the new standard for what a 250 dual-sport can be. The 250 EXC-F is a pleasant surprise.
Despite its smaller displacement, it’s quite good both on the tarmac and dirt. It supplies a decent amount of pep and offers plenty of power out on the trail. Like its motocross brother, the 250 produces most of its power through the mid and way up into the high-revving top-end. Its overall light weight and flickable chassis make the 250 EXC-F a pure joy to navigate in tight, single-track trails. It has plenty of power to wheelie when needed. In deep sand and big hillclimbs, however, the 250 struggles a bit, but that’s to be expected. In these conditions, it just doesn’t have the power when compared to the 350 and 500.
The little 250 also labored a bit to keep up on the longer asphalt sections of our 115-mile loop, especially if there was a headwind. It will pull 65 mph on flat ground in no wind, but we don’t recommend battling it out on the freeway with big rigs and distracted drivers on the 250 EXC-F; or any single-cylinder 250 for that matter. However, there isn’t another 250cc dual-sport that could even keep the 250 EXC-F in sight for more than 10-seconds. For a small, light or beginning rider, the 250 EXC-F is a dream come true. For aggressive off-road riders who like riding 250Fs and know what a 250F engine is all about, the 250 EXC-F will happily provide impressive upper-rpm power while putting a large smile on your face.
The suspension and handling of the 250 EXC-F mimics that of the 350 EXC-F, but doesn’t feel quite as plush. This is due to a microscopic weight difference and less horsepower through the chassis. The ultra-plush settings compliment the softer power output and combine to create a super-fun bike to ride. It is very quick-turning and a blast to flick through tight, twisting single-track.
The biggest limiting factor on all of the EXC-Fs comes down to the TKC 80 tires. Finding an aggressive, knobby DOT tire, like Dunlop’s 606s, will greatly enhance the off-road experience on any of the EXCs.
Separated By Displacement
As we mentioned, these three bikes share almost everything, besides displacement. The brakes on all three EXCs work amazingly well, and the overall fit and finish is excellent. Gas tanks might hold only 2.2 gallons, but we were still able to get 80-90 miles in normal trail-riding conditions. Somewhat surprising was that each bike seems to burn at about the same rate.
There isn’t a kickstarter on these bikes, but there is an option to install one if you want. We did not have any reliability problems or issues with the electric starting system, and overall starting is effortless. The lithium battery that the EXCs use is light and provides plenty of power while saving weight when compared to a typical lead-acid battery. The hydraulic Brembo clutch works smoothly, always providing a consistent feel to the clutch, which has a lot to do with KTM’s DDS design that uses only one big, central spring instead of multiple springs.
To help eliminate any overheating issues, even in tight and slow riding situations, all three bikes have an electric fan.
KTM put a lot of work and thought into the 2017 EXC-F so you don’t have to do any modifications before hitting the trails for the first time. They run pretty darned good as is! Of course, a dirt biker’s natural tendency is to modify, but we suggest you take the time to ride them stock for a bit and figure out what you really need to change. You just might find that you don’t need to change a thing. The ECUs are locked up tight but work very well as is. As soon as you start messing with the engine—anything that is related to emissions—it suddenly takes them out of EPA compliance, and they probably won’t run any better, either; instead, most likely worse, because the tamperproof ECU unit can’t be re-mapped, which you would normally have to do following any modification to anything that has to do with air flow into and/or out of the engine, such as installing a different muffler or exhaust system.
Orange Choices
So, which EXC-F is best for you? Depends on what kind of riding you do, your ability and how much you weigh. Our group of testers was split down the middle between the 500 EXC-F and the 350 EXC-F. The 500 was the all-around king of doing everything well, while the 350 EXC-F ruled the more technical and tighter single-track trails. The 350 won’t be great if you spend a lot of time burning up the miles on the pavement, but the 350 is magic in the off-road world. The 250 EXC-F was a pleasant surprise and performed better than we had expected.
All three EXCs are amazing dual-sport bikes, or should we say enduro bikes with plates? The 500 will certainly tend to favor larger and more experienced riders, while the 350 will appeal to a wider variety of riders, both in size and riding ability. The 250 will appeal to a smaller niche of riders, like those who are lighter in weight, or for those who want something a little less aggressive when you open up the throttle but still want high-end off-road performance when it comes to handling and suspension for technical trails. And it doesn’t hurt that the 250 retails for $1300 less than the 500 and $1000 less than the 350.
Basically, all three EXCs have a reason for being, without question. You just have to decide what that reason is for you. But don’t worry about it too much; whichever one you choose, you really won’t be sorry. CN
SPECIFICATIONS
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KTM 500 EXC-F
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KTM 350 EXC-F
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EXC-F
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MSRP:
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$10,699
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$10,399
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$9,399
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ENGINE:
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SOHC, 4-stroke, single
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DOHC, 4-stroke, single
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DOHC, 4-stroke, single
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DISPLACEMENT:
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510cc
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349.7cc
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249.9cc
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BORE X STROKE:
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95.0mm x 72mm
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88mm x 57.5mm
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78mm x 52.3mm
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COMPRESSION RATIO:
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11.8:1
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12.3:1
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12.8:1
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FUEL DELIVERY:
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42mm EFI
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42mm EFI
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42mm EFI
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STARTING SYSTEM:
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Electric
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Electric
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Electric
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TRANSMISSION:
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6-speed
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6-speed
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6-speed
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FINAL GEARING:
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14/45
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14/52
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14/49
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FRAME:
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Steel
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Steel
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Steel
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FRONT SUSPENSION:
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WP Xplor spring fork,
rebound/damping adj.
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WP Xplor spring fork,
rebound/damping adj.
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WP Xplor spring fork,
rebound/damping adj.
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REAR SUSPENSION:
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WP Xplor PDS Single shock, preload/rebound damping adj.
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WP Xplor PDS Single shock, preload/rebound damping adj.
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WP Xplor PDS Single shock, preload/rebound damping adj.
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FRONT WHEEL TRAVEL:
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11.8 in.
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11.8 in.
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11.8 in.
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REAR WHEEL TRAVEL:
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12.2 in.
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12.2 in.
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12.2 in.
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FRONT WHEEL:
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90/100×21 in.
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90/100×21 in.
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90/100×21 in.
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REAR WHEEL:
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120/100×18 in.
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120/100×18 in.
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120/100×18 in.
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FRONT BRAKE:
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260mm Disc
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260mm Disc
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260mm Disc
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REAR BRAKE:
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220mm Disc
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220mm Disc
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220mm Disc
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RAKE:
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63.5°
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63.5°
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63.5°
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GROUND CLEARANCE:
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13.1 in.
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13.1 in.
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13.1 in.
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SEAT HEIGHT:
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37.8 in.
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37.8 in.
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37.8 in.
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WHEELBASE:
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58.3 in.
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58.3 in.
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58.3 in.
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FUEL CAPACITY:
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2.2 gal.
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2.2 gal.
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2.2 gal.
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WEIGHT (Wet):
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258 lbs.
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254 lbs.
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253 lbs.
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