Kawasaki’s changes to the model designations of its KLX family of dirt bikes give us a chance to revisit old favorites—in this case, the 2021 Kawasaki KLX140R F. Previously known as the KLX140G, the renaming features an R after the number for all the KLXes. That means we have the KLX110R, KLX140R, KLX230R, and KLX300R. In the case of all but the flagship KLX300R, there are variants, and they get a space followed by an extra single-letter designation. So, the KLX140G is now the KLX140R F, the largest of three KLX140R dirt bikes.
The base Kawasaki KLX140R is definitely for smaller riders, with a 30.7-inch seat height. With the KLX140R L as a midway point, the KLX140R F is a higher-performance platform for the 140R motor and frame. The F boasts longer travel suspension, longer wheelbase, and full-size wheels, making it much more capable of handling challenging off-road trails. It’s also easier to ride faster.
The 2021 Kawasaki KLX140R F has 7.5 inches of non-adjustable fork travel, which is somewhat oddly matched to a fully adjustable linkage-assisted piggyback-reservoir shock. The F has four-way compression damping adjustments, which makes sense, but a bewildering choice of 22 rebound damping settings. Really, four positions might invite a 140R F rider to investigate the options, but selecting the right one of 22 clicks is intimidating, even for experienced riders.
There is some good news, fortunately. The standard settings are pretty much spot-on for the intended rider size. With a 30.5-inch inseam and 5’ 6” overall height, I’m right at the top edge of riders who will fit the 2021 Kawasaki KLX140R F. I tip the scales at 115 pounds and ride at a moderate pace—the 144cc motor only goes so fast—and I didn’t miss any fork adjustments. I felt no need to fiddle with the shock clickers or spring preload.
A rider learning to ride harder could benefit from the shock adjustability, though one wonders about the suspension balance if all the changes are made at one end. For heavier or more aggressive riders, Cogent Dynamics makes a $377 fork kit for the KLX140R F that upgrades the springs, damping, and oil to firm up the action.
One would be rightfully skeptical of Kawasaki taking a kid’s KLX140R and turning it into an adult motorcycle via longer travel suspension, a three-inch longer wheelbase, and a full-size 21-/18-inch wheelset. The good news is that the chassis makes total sense in the dirt. It doesn’t have any bad habits that will reveal themselves at the intended speeds of the KLX140R F.
The larger wheels and longer travel suspension pay multiple dividends. The advantages of longer-travel suspension are obvious off-road—you can suck up harder hits without making the suspension excessively firm. Large wheels provide more gyroscopic effect, adding stability to the compact chassis, and the larger diameter wheels more easily roll over rocks, roots, and other trail obstacles. Additionally, you have access to premium rubber with full-size wheels. Also, the combination of the longer travel suspension and larger wheels provides 4.1 inches more ground clearance than the standard Kawasaki KLX140R—a significant help on technical trails.
A nice benefit of basing the small-adult size KLX140R F on the kid’s KLX140 chassis is the weight. The KLX140R F weighs in at an easily handled 218 pounds wet. With the easy and predictable power of the motor, plus the nimble chassis, the KLX140R F can be ridden just about anywhere.
Sure, you can’t ride it nearly as fast as you can something like the similar-weight Husqvarna TE 150i, but you can ride on most of the same trails. Someone too short for a full-size enduro bike can still tag along on those black-diamond trails on the KLX140R F. Again, those on bigger bikes might have to wait up for the other rider, or even provide some assistance, but the KLX140R F will get there.
The air-cooled, SOHC, two-valve motor offers competent performance and no surprises. If you want to loft the front wheel, be prepared to manipulate the throttle and easy-pull clutch, unless you find a nice rock or log to help you get the front end up.
Traction is easy to find with the four-stroke’s power delivery, and the budget-minded IRC Vulcanduro tires work fine. Turning the Kawasaki KLX140R F is effortless, and the handling is well-mannered. The F is not a dirt bike for big air or skipping whoops, and I doubt anyone will buy it with that in mind. It’s a fantastic trail bike intended to create ear-to-ear grins on the faces of recreation-oriented riders.
From a convenience standpoint, the 2021 Kawasaki KLX140R F has most of the bases covered. It is electric start, but it does have a carburetor. We were happy that the KLX140R motor isn’t quite as cold-blooded as some small trail bikes, and didn’t require long warm-up sessions or routine choke engagement. Still, we prefer EFI—Honda made it happen, so Kawasaki can, too.
Changing the oil and oil filter won’t challenge even the most ham-fisted mechanic. Tools are needed to access the airbox and air filter, though it’s still pretty easy. Chain adjustment is the standard bolt-and-locknut system—simple. The disc brakes are adjustment-free and will likely never require maintenance. Oh, and the brakes have just the right feel and power.
I haven’t mentioned the wide footpegs yet—they provide a secure platform for your boots. The foot controls, like the hand controls, are right where you want them to be. Also, the seat is comfortable enough for all-day rides. The styling is very “big bike,” so you don’t feel like you’re riding a lesser motorcycle.
The 2021 Kawasaki KLX140R F is aimed at two sets of riders. It’s excellent for a younger rider growing up and moving up the trailbike ranks. It’s also a good entry point for an adult of smaller stature who wants to avoid the limitations of a mini. Dirt bike riding has been booming, and motorcycles such as the KLX140R F are there to keep that momentum flowing.
Photography by Don Williams
- Helmet: Fly Racing Formula CC
- Goggles: Fly Racing Focus
- Jersey, gloves + pants: Fly Racing Women’s F-16
- Body armor: Alpinestars Stella Bionic
- Knee braces: Pod K4
- Boots: Fly Racing FR5
2021 Kawasaki KLX140R F Specs
- Type: Single-cylinder 4-stroke
- Displacement: 144cc
- Bore x stroke: 58.0 x 54.4mm
- Compression ratio: 9.5:1
- Valvetrain: SOHC; 2-valves
- Cooling: Air
- Fueling: 20mm Keihin PB
- Transmission: Close-ratio 5-speed
- Clutch: Wet multi-disc
- Final drive: Chain
- Frame: Steel box-section perimeter
- Front suspension; travel: Non-adjustable 33mm fork; 7.5 inches
- Rear suspension; travel: Linkage-assisted, fully adjustable piggyback reservoir shock; 7.9 inches
- Front tire: 2.75 x 21; IRC Vulcanduro VE-35
- Rear tire: 4.10 x 18; IRC Vulcanduro VE-33
- Front brake: 220mm petal disc w/ 2-piston caliper
- Rear brake: 186mm petal disc w/ single-piston caliper
DIMENSIONS and CAPACITIES
- Wheelbase: 52.4 inches
- Rake: 27 degrees
- Trail: 4.6 inches
- Seat height: 33.9 inches
- Ground clearance: 12.4 inches
- Fuel capacity: 1.5 gallons
- Curb weight: 218 pounds
- Color: Lime Green
2021 Kawasaki KLX140R F Price: $3749 MSRP