❏ In most series, we see a pretty good
mix of race machines by all manufacturers. However, for some reason,
Honda has virtually dominated all
of the top spots in Extreme Dirt Track
(TT) racing for the last decade. Well,
Yamaha and Rath Racing want to
change that. No, they are not hiring
away the top guys or dumping a
bunch of money into sponsoring the
sport; they are going about it another way. Rath Racing is building up
a top-level 2014 Yamaha YFZ450R
just to show it can be done. Yamaha
hopes their effort will pay off and
attract more of these flat trackers and
their friends to the brand, and Rath is
up to the challenge.
STARTING FROM SCRATCH
There has been no one on the top
level campaigning a YFZ450 for years
in this discipline, so Rath had noth-
ing to go on except years of building
many other brands of competitive
flat-track machines. “So the basics
are the same,” Daryl Rath (owner
of Rath Racing) tells us. “You need
high horsepower and low weight to
be fast here. We know what it takes
to be competitive in TT, so we just
had to find ways to shave weight and
build a fast YFZ450R. Chad Wienen is
doing it on the MX scene, so we knew
it could be done.
TIPPING THE SCALES
The stock YFZ450R weighs in at just
over 400 pounds with 2. 5 gallons of
gas. After nerf bars, larger footpegs,
steering stabilizers and other goodies
are installed, a typical MX YFZ450
hits the track at about 420 pounds. In
the extreme flat-track world, exotic
materials like titanium and carbon
fiber are more prevalent, and most of
the pros’ quads weigh about 350, so
that is the mark Rath was shooting for
with this build. To achieve this goal,
steel had to be replaced by aluminum
in a few key locations, along with a
couple other secrets he filled us in on.
Up front, Rath built new lower
chromoly steel A-arms and paired
them with a set of aluminum uppers.
The complete set retails for $925. The
tie-rods were replaced by $325 car-
bon fiber tie-rods with aluminum rod
ends. Stock is all steel. The steer-
ing stem was also replaced using a
non-welded, bolt-together aluminum
stem that is three-fourths lighter ( 2
pounds). The spindles are stock, but
the hubs are Rath’s own hubs that
produce less drag and help the quad
corner like it’s on rails. Rath sells
these $430 (a pair) hubs for 4/144- and
4/156-bolt patterns. Daryl uses 18x5.5-
10 Hoosier RD12 compound tires up
front. In the rear, he uses 18.5x9-10s.
All four tires are mounted on DWT A5
wheels.
Out back, the stock swingarm was
replaced by a chromoly swingarm
that measures 2 inches shorter than
the stocker. It costs $925 complete
with a bearing carrier. A Rath Racing
lowering link ($325) allows the quad
to still ride smooth, even though the
swingarm and shock are shortened.
The combo really makes the YFZ450R
transfer weight well and get off the
starting line fast and hook up out of
the corners. The axle and aluminum
rear hubs are all Lone Star Racing
products.
The seat has been lightened and
lowered, as well as the subframe.
The subframe also has a new bracket
DIRT-TRACK