Factory Services pumps out the jams on Osborne’s FC250.
The rev limiter is set to a hair under 15,000 rpm.
A radiator fan automatically kicks on once the temperature
sensor reads 185 degrees.
weight but costs $100. The fastest of the fast racers on
the professional circuit are able to bend titanium
( 2) Steering damper. Just as on Ryan Dungey’s
Red Bull KTM 450SXF, Zach Osborne uses a steering
stabilizer that mounts to the head tube and the bottom
triple clamp. The stabilizer is conveniently hidden behind
the front number plate. KTM didn’t like us calling them
out for using a Honda HPSD damper, which comes on
any late-model CRF250 and CRF450, but a spade is a
spade. KTM and Husqvarna are guilty of using a
competitor’s steering damper.
( 3) Radiator fan. Without a shadow of a doubt,
the most unique part on Osborne’s bike is the radiator
cooling fan system. How does it work? A fan is mounted
behind the right-side radiator, with a temperature sensor
embedded into a cooling fin on the backside of the
radiator. An external temperature gauge displays the
coolant temperature. When the coolant reaches 185
degrees, the fan automatically kicks on. The fan keeps
the engine temperature operating as close to 185 degrees
as possible, which is the sweet spot for maximum
performance. That’s really cool (no pun intended). The
fan runs off a 3200-milliamp Horizon Hobbies battery.
WHAT ARE OSBORNE’S BIKE SETUP
PREFERENCES? Zach Osborne will never tower
over a crowd, unless that crowd is in line to get on the
teacup ride at Disneyland. Osborne’s short stature doesn’t
hinder him from going incredibly fast around a track,
though. The 5-foot- 7 Virginia native has his mechanic,
Dave Feeney, set up the Husqvarna for his height. The
subframe is lowered 10mm, and the seat foam is cut
down. Osborne’s Raptor titanium footpegs are also 2mm
lower and 5mm back from the standard position. Zach’s
preferred bar mount height is 35mm above the Neken top
triple clamp, and the Pro Taper Fusion handlebars are a
special bend that mimics the Carmichael bend and are
not available to the general public. Osborne cannot run
the Neken SFS air triple clamp, because his preferred
bar mount height is too low.
WHAT CAN’T BE NOTICED BY THE NAKED
EYE? A close inspection of the Raptor footpegs reveals
unique mud stoppers that are self-cleaning and keep dirt
from becoming lodged in the springs; however, even
Sherlock Holmes would have difficultly uncovering that
Osborne runs bib mousse foam in his front and rear
tires. The fact that Zach runs a mousse rear shouldn’t
come as a surprise. After all, most factory riders on the
outdoor circuit use foam in place of a tube to prevent a
costly DNF. Very few opt for a mousse front, because the
mushy feel of the tire creates an uneasy sensation during
corner initiation. That doesn’t bother Osborne. He used
mousse inserts on the Grand Prix circuit for years, and
his preference hasn’t changed since returning to the U.S.
The Rockstar Energy Racing team doesn’t mind, because
the possibility of Osborne getting a flat is gone. By the
way, the front mousse is comparable to running around
9 pounds of air in a tube.
WHO BUILDS OSBORNE’S FC250 ENGINE?
Our test riders swore that Osborne’s powerplant was
designed, developed and created in the inner sanctum at
NASA. Why? The engine was a rocket ship, capable of
reaching the stratosphere while bouncing off the 15,000
rpm rev limiter in second gear. Truth be told, Factory
Services takes care of Zach’s engine needs. Andy Smith
and Dudley Crummen supercharge the FC250 engine, and
while the RER team kept the details of Osborne’s engine
secret, it’s safe to say that each component is made with
unbridled horsepower in mind. Osborne’s powerplant is
rebuilt after every National to keep things working.