The biggest engine mod is to the cylinder head. It doesn’t share a single part with last year’s head and is 15mm shorter.
more engine braking, which was disliked. Map two revved
out farther, felt freer and didn’t have as much engine braking, but gave up some of the superior traction that came
with map one. Overall, most test riders preferred map one,
even if they complained about engine braking entering
turns. To tell the truth, we expect better maps by the
time the 2019 production bikes hit the showroom. Why?
Because compared to the smooth, arcing power curve
of the 2018 production bike on the dyno, the 2018-1/2
Rockstar Edition’s curve wavered up and down as though
it was too lean. We couldn’t feel it on the track, but no
engineer is going to let that pass without doing something
The Husqvarna Rockstar FC450 has an educated and
sophisticated powerband. The smartest way to race it is
to carry speed, keep your momentum up, and rely on late
braking and smooth entrances. If you are a Bam Bam-style
rider, don’t apply. This bike is built for tacticians who use
the metered power to cover ground fast, not spray it into
the air. Oh, don’t get us wrong; this is still a 58-horsepower
machine that doesn’t have to bow down to anyone off the
start or on fast straights; it just does it with less drama.
Compared to its closest relative, the KTM 450SXF, the
FC450’s power delivery is easier to manage. But, its friendly 450 personality pales in comparison to the KTM 450SXF
Factory Edition’s snappier, more responsive and quicker
power delivery. Don’t blame any of this on the crankshaft
lobes, piston, exhaust or throttle body of the FC450 engine.
The blame lies in our old friend, the Husqvarna’s closed-off
plastic airbox. It doesn’t breathe, just as it didn’t breathe
last year, the year before or the year before that. To prove
it to ourselves and to the Husqvarna engineers, we pried
the airbox cover open by 1 inch and sent test riders out to
ride with the added airflow. Guess what? The FC450 was
snappier, more responsive and had quicker power delivery.
Q: HOW GOOD ARE THE ROCKSTAR EDITION
A: Initially we had issues with the Rockstar Edition’s
WP AER forks. The changes that WP made to the 2018-
1/2 AER forks altered the setup quite a bit from the
previous fork. The new forks exhibited some harshness
at mid-stroke of their travel. Luckily, the air pressure is
easily modified, which effectively changes the spring rate,
so we lowered the air pressure to soften the forks in the
middle. This worked, but our AMA Pro test riders felt that
lowering the air pressure allowed the front of the bike to
drop on corner entrances and to dive on the face of jumps.
However, our Vet test riders were all for lowering the air
pressure even more. Once we satisfied both the fast and
slow test riders with their speciifc air pressure needs, we
focused on the compression clicker. Surprisingly, four out
of five test riders, regardless of their speed or age, selected
the exact same clicker setting—which was all the way out.
Their air pressures were vastly different, but their compression settings were the same. Thankfully, we brought
our 2018 production FC450 to run back to back against the
new fork. Test riders preferred the 2018 production fork. It
was plusher and had compression clicks left when dialed
in. Our goal was to find that comfort level on the 2018-1/2.
It was important for us to find a solution that every rider
could do without having to resort to expensive experimental fixes. We asked our WP technician to lower the fork-oil
height in the damping leg by 10cc (just the damping leg,
not the air leg). WP suggested 20cc. We went with their
recommendation. With the lower oil height the forks got
plusher, had no mid-stroke harshness and we had compression clicks to play with. For most skill levels, this setting
was the most workable. The fast riders could run higher