RIDING THE HUSKY FE501 / 250 MX DYNO TEST: THE WRAP

We got a chance to ride the 2021 Husqvarna FE501 this week. This is the dirt-only model, not the -S, which is street-legal. This bike is still blessed by the EPA in terms of emissions and noise. In the overall Husqvarna model line, here’s how it plays out:
FC450: Motocross bike with a 5-speed gearbox, Xact air fork and a linkage shock, producing around 57 horsepower.
FX450: Off-road racer with the same five-speed, a softer Xact air fork and linkage shock, also producing around 57 horsepower.
FE501 (shown here): Trail bike with a similar motor. Longer stroke, but overall in a milder state of tune. Six-speed gearbox, Xplor coil-spring fork, linkage shock. Output is around 45 to 50 horsepower.
FE501S: Dual-sport bike with similar motor, gearbox and suspension. Subject to more stringent noise and emissions, plus DOT regulations. Catalytic converter. Output around 40 horsepower.

In the overall Husky/KTM/GagGas hierarchy, the FE501 is highly regarded among desert racers because it’s the only one that combines the six-speed with linkage rear suspension. The KTM 500XC-W has a PDS shock and all of the competition-oriented models like the 450XC-F and FX450 have five speeds. We know of at least one desert racer who has installed the transmission from this bike in his KTM 450XC-F. If he were to start with this bike, he would have a different set of modifications to make, mostly revolving around getting more bark out of the motor and stiffening up the suspension.

In stock form, there’s nothing wrong with the performance of the FE501 in its intended role as a trail bike. The motor is delightfully quiet and well mannered. Its low-end power isn’t that far off the mark. Where it falls short of a competition bike like the FX450 is in revs. It runs great up to 7000 rpm or so, then goes flat.  An FX is still going strong all the way to 10,000 rpm, and that’s where the difference in horsepower happens.

On the trail, no one likes revving a bike like that, so the FE501 is perfect. For a big bike, it’s very easy to ride. Part is due to the mild power, part is due to relatively light weight. The FE501 weighs 242 pounds without fuel on our digital scale. That’s only slightly heavier than a Yamaha YZ450F motocross bike. The suspension is super soft and cushy, too. The debate over linkage rear suspension vs PDS will go on forever, but if you had to simplify things, it would break down like this: if you had two bikes set for the same rider and skill level, the PDS one would work best below 30 mph. The linkage one would be better at anything faster. Almost everyone will disagree with one side of that analysis or the other. Send your outrage to [email protected].

Almost everyone will want to mold the FE501 into something more personalized. Some will want to take it racing and in some parts of the country, it will pass for a dual-sport bike. We’re just pleased that it works so well without any modifications at all. The motor doesn’t flame out or overheat. It’s everything it should be–and it can be much more. For the full test, check out the June, 2021 print edition of Dirt Bike.

250s ON THE DYNO

Our 2021 250 MX shootout was delayed for various reasons, but it will finally be appearing on Youtube later in the week. We still believe in doing a thorough job, which means waiting to include all the bikes currently available.  We ride them, weigh them (after draining the fuel tanks) and ultimately running them on the Pro Circuit dyno. Often, the dyno just confirms what we already know. Sometimes there are surprises. This year, the most striking result was how close most of the bikes were in peak horsepower.

Honda CRF250R: 42.52 hp @ 12180 rpm, 20.19 lb/ft @ 9240 rpm
Yamaha YZ250F: 42.60 hp @ 12860 rpm, 19.85 lb/ft @ 9960 rpm
Kawasaki KX250: 43.90 hp @ 13410 rpm, 20.81 lb/ft @ 9390 rpm
KTM 250SX-F: 44.22 hp @ 13870 rpm, 20.79 lb/ft @ 8980 rpm
Husqvarna FC250: 44.04 hp @ 13790 rpm, 21.11 lb/ft @ 8930 rpm
GasGas MC250F: 43.85 hp @ 13650, 20.71 lb/ft @ 8850 rpm
Suzuki RM-Z250: 39.14 hp @ 12220 rpm, 19.28 lb/ft @ 9330 rpm

There are a number of good reason for dyno testing. This test provided one clear-cut example. We heard people say that the YZ250F made the most low end power. It’s not true. All the KTM-powered bikes have more low end power and higher peak torque. Once you understand that, you can more accurately analyze what’s happening. The Yamaha excels at partial-throttle openings, whereas the KTM group is best at full throttle. If you know that, it actually helps you tailor your riding style to a specific bike. Or, more relevantly, choose the bike that best matches your riding style.

EXTREME TM

If you check out Two-Stroke Tuesday from a couple of weeks ago, you can read about the Extreme TM two-stroke that was built by Get Dirty Dirt Bikes in Morongo Valley. We got to ride one of them since then and came away very impressed. It might sound odd, but the one thing that caught us a little off-guard was how well the Gekkota Extreme IRC tires worked on EnduroCross types of obstacles. They almost require a different riding technique. As for the bike itself, it was nearly perfect for getting over big, scary things. You can read more about it in the June, 2021 print edition of Dirt Bike.

MESECHER CLAN

Robb Mesecher is an advertising big wig at Dirt Bike as well as being a former District 37 Enduro Champion and ISDE medalist. He and his son Mitchell are tentatively exploring the prospect of a father/son team at the ISDE. It might not happen in Italy this fall, but the process often takes a couple of runs in the ISDE Qualifier series, which starts this weekend. They built a couple of interesting Husqvarnas. Robb is on a fuel-injected Husky TX300 and Mitchell is on a heavily modified. Look for more on these bike in coming weeks.

See you next week!

–Ron Lawson