KTM 450 SX-F 2018:DROP THE HAMMER
If gold is what you’re after, a KTM 450 SX-F is what you get. Thanks to its compact engine delivering explosive but controllable power, it’s the weapon of choice for the Red Bull KTM Factory Racing Team and the champion, Ryan Dungey. This READY TO RACE bike rules the AMA Supercross Championship. Its secret? Precise handling and arm-stretching grunt. Winners - line up here.
The hugely successful 450 SX-F powerhouse has extremely
compact dimensions, strong performance throughout the rev
range and a low weight; this is the lightest 450 engine
on the MX market. But that doesn’t mean it’s not a heavyweight
in terms of muscle. Fitted with a single overhead camshaft cylinder
head and the latest electronic fuel injection, it pumps out an
unrivaled 62hp. With KTM’s engineers working tirelessly to increase
service intervals, this super stroker has the latest engine management
technology on board and confidently shoots both
amateurs and pros to the top of their time sheets.
Inside the SOHC cylinder head, an overhead camshaft controls
four ultra-lightweight titanium valves via extremely
rigid rocker arms, which are DLC-coated on the intake side. A
configuration like this allows engine speeds of up to 11,500rpm;
a baffling figure for a large displacement thumper. Lateral
brackets made of aluminum allow an efficient fixation of the
engine to the frame and contribute to the bike’s featherweight feel.
The KTM 450 SX-F’s crankshaft utilizes a short connecting rod,
which makes for an overall compact and lightweight engine
with a snappy power delivery. A plain big (bottom) end
bearing with two force-fitted bearing shells runs directly on
the crank pin. The necessary oil feed for this bearing is ensured
by the engine’s pressurized lubrication. This design is a
decisive benefit in terms of the crankshaft service interval,
which can be lengthened due to the plain bearing.
So just pin it, all day long.
CRANKCASES AND COVERS
The design of the die-cast crankcases allows for minimal
weight and a very centralized shaft configuration. This makes the
engine short and compact, while contributing to an efficient
centralization of masses. The engine covers also feature a solid surface
structure, which reduces the wear caused by the rider’s boots.
This way, your SX-F will keep looking better longer.
The KTM 450 SX-F uses a lightweight 5-speed transmission with
gear ratios that are perfectly matched to the power delivery
of its large displacement engine. The 1st and 3rd gears
are treated with a special surface coating for better reliability.
An advanced ´No Dirt´ gear shift lever design prevents mud
and sand from blocking the joint of the lever and guarantees
trouble-free shifting. All 4-stroke engines are fitted with
a gear position sensor, giving the option of different engine
characteristics for each gear. In MY2018, the transmission shaft gets
a stronger shifting star and a C4 bearing that has a bigger
overlap in the case. This guarantees better reliability even at
extremely high operating conditions. Think GP-level riding.
In knee-deep sand.
ENGINE MANAGEMENT SYSTEM
The state-of-the-art Keihin engine management system with
electronic fuel injection features a 44mm throttle body.
Thanks to its unique injector position, the engine’s response
is instantaneous. And to make life even easier, separate systems for
cold starts and idle adjustment await you. The lightweight control
unit features a unique traction and launch control system for
lightning-quick response when the gate drops and maximum
grip thanks to different maps that sync with to the gear
you’re in. It’s also possible to unleash an even more powerful
mapping via the handlebar map select switch.
CYLINDER AND PISTON
Inside the short cylinder, with a bore of 95mm, thumps a
box-type piston made by CP. Its crown geometry is
adapted perfectly to the high-compression combustion
chamber, where its rigid structure and low weight shine.
Thanks to the low oscillating masses, the engine
is as snappy as it is strong.
The side mounted counter balance shaft also drives the
water pump. Thanks to its perfect balance and low oscillating
masses, engine vibrations are kept to a minimum. Even
when revving it all the way up to the maximum,
just the way an SX-F likes it.
The KTM 450 SX-F employs the KTM-developed DDS clutch
(damped diaphragm steel) with a robust steel basket, extremely
heat resistant clutch plates and new, nitrated steel liners
reducing the wear. This clever design employs a diaphragm spring
instead of the usual coil springs, making for considerably easier
clutch action. A diaphragm spring also leaves sufficient space for
a damping system to be integrated into the clutch hub.
The goal is traction, but durability is as well. Light operation and telepathic
amounts of control are standard with this hydraulic Brembo
The KTM 450 SX-F is fitted with a unique E-starter as standard,
which is a clear advantage when it comes to crunch time
in the heat of battle. A strong starter motor made
by Mitsuba will fire time and time again at the push of a button.
KTM’s proven cooling system routes the coolant from the
cylinder head through the frame triangle, directly to aluminum
radiators made by WP. Thanks to flow optimized internal circulation
and CFD-calculated ventilation, the system is superbly efficient.
In addition, new radiator protections improve heat dissipation.
Especially in the mud. They are also integrated into the front
part of the shrouds to protect the radiators in a crash.
KTM engineers just love dropping weight year after year. The result:
the 2018 KTM SX models are the slimmest, lightest dirt bikes
out there. Even though the 4-strokes are equipped with
an E-starter as a standard feature, while the competition
still needs to be kickstarted. You can just focus on kicking ass.
The high-tech, lightweight chrome-moly steel frame has a knack
for easy handling, outlandish rideability, precise cornering and
excellent stability. You can also count on high torsional rigidity
and low longitudinal stiffness. This results in better absorption
of the energy created from the front and rear suspension,
sucking up jumps and bumps. In short: more comfort and less
rider fatigue. Laterally attached, lightweight aluminum engine
head stays (the connection between cylinder head and frame) contribute
to more precise cornering and a reduced vibration level. The
engineers were able to pull off all that, while making their frame
a big fat kilogram lighter than that of the lightest competitor
on the market. In addition, it is easier to maintain, easier to work
on and supplies more space for the tank and other components. The bike also
features an extra-light subframe made of stable aluminum
profiles, which tiptoes the scales at less than 900g.
Sophisticated ´No Dirt´ footpegs prevent clogging of the
footpeg pivot, even when digging in deep ruts. Looking
for a higher riding position? Then just mount the footpegs
of the MY2018 EXC models, which are 6mm higher than the
AIR FILTER BOX
The airbox design offers maximum protection of the air filter against
soiling, while ensuring maximum airflow. The large twin-air
filter is mounted in a stiff cage, which at the same time holds
the system in place. This design is so simple, you could still
pop a fresh one in with a face full of mud. Without
tools. In seconds.
FIM noise limits are a real challenge for every manufacturer.
Therefore, KTM has put a lot of effort into the development
of their exhaust systems. All 4-strokes are fitted with headers
that have a unique standard feature; an additional resonator
system – a small chamber connected to the pipe. All 4-strokes
are fitted with a short silencer, mounted as close to the engine as
possible. You know what that means: extra mass centralization
and better rideability. Its advanced internal design reduces the
noise sufficiently in order to sit safely below the noise limit,
while still raising the hairs on your neck.
KTM engineers sure know how to handle handlebars. This tapered
one, made of high-strength aluminum, is fixed in damped
rubber mounts and has two different positions.ODI lock-on
grips make grip changes easy and do not require any
wire or glue to be secured.
The cast aluminum design offers low weight and a perfect flex
behavior. The single-component casting process eliminates
any inconsistencies and inherent weak points
created by welding. It’s better looking too.
A lightweight polyethylene tank with a capacity of 7.0 liters.
The fuel tank cap has an inside thread, which
makes for easy and reliable closure.
The KTM wheels feature lightweight, CNC machined hubs
and high-end Excel rims guaranteeing maximum
stability at minimum weight. The wheels are fitted with
the latest Dunlop Geomax MX 3S tires.
The WP monoshock has been developed with the entire
frame and swingarm architecture in mind, including the
linkage system and the WP AER 48 front forks. It features
machined and black anodized components and is a valuable,
high-end product compared to roughcast reservoirs. A new
setting and a softer spring perfectly match the reworked front-end
set-up and its sparkling WP color scheme lets everyone
know you have excellent taste in suspension.
The lightweight WP AER 48 front fork, a 48mm USD air-sprung fork
developed by WP in close collaboration with KTM, is a split
fork with separate functions for each leg. That means damping functions
are on the right side, whereas the air spring is in the left.
This left leg features a 2-chamber system with a capsuled air
cartridge to prevent loss of air pressure. Should the outer
seal start to leak, the internal cartridge pressure will keep the bike
in position. The air spring is easy to adjust to any rider
weight via a single air valve. No special tools are required; the
fork air pump supplied with the bike will do just fine. The right
fork leg integrates a damping cartridge that tailors to all your
damping needs. It can be adjusted to the track conditions and
the rider’s preferences with a twist of a dial (compression from the top,
rebound from the bottom, 30 clicks each). Right off the dealer floor, this
fork (with reworked damping characteristics) is more comfortable and more
sensitive than ever. But you can still hammer the hell out of it.
Top quality, CNC machined triple clamps have been a KTM trademark
for years to ensure precise handling. The rubber damped handlebar
fixation allows for two positions and an hourmeter is fitted in
order to let the rider know it’s time for a service.
Top quality, CNC machined triple clamps have been a KTM trademark
for years to ensure precise handling. The rubber damped
handlebar fixation allows for two positions and an hourmeter
is fitted in order to let the rider know it’s time for a service.
HANDLEBAR MAP SELECT SWITCH
All 4-stroke models are equipped with a sophisticated new
multi-functional handlebar map select switch, which does
three things: Activation of the traction control Activation of the
launch control Selection of an alternative power curve (Standard or
Advanced) The traction control is a unique feature that
none of the competitors can offer. It guarantees more efficient
traction when the track conditions are less than perfect.
Push the tip switch and reign supreme. With this map select
switch the rider can also activate the launch control, which
provides more efficient starts out of the gate so you can go
for the holeshot, time and time again. How? It simply reduces the maximum
engine speed for the very first moment of the start, in order
to give you better control. Push both tip switches when the
engine idles and the EFI control lamp mounted on the upper
triple clamps will let you know you are READY TO RACE.
In addition, the map select switch gives the rider the chance
to select an alternative, more powerful map beside
the standard configuration. Welcome to the future.
BATTERY & WIRING HARNESS
A strong new lithium-ion battery breathes life into the engine and
contributes to low vehicle weight. The lightweight battery and
wiring harness are centralized in a compartment above
the air filter box, allowing the mechanic to remove the
subframe without getting in conflict with the electronics.
A happy mechanic is a good mechanic.
Like all KTM 4-stroke motorcycles, the 450 SX-F is started
at the push of a button - a priceless advantage when
you’re on the clock.
KTM R&D, KISKA Design and all our factory riders had
their say in shaping the plastics with one goal: complete
harmony between rider and bike. Perfect ergonomics and contact
points provide maximum comfort in movement on the SX-F.
The I-beam structures of the front and rear fenders
guarantee maximum stability and a low weight thanks to well
thought-out construction and mounting.
They also stay cleaner for longer.
A new, tailor-made kit and a Factory orange frame. Because
in this sport, champs deserve to look the part regardless of the dirt.
|Design||1-cylinder, 4-stroke engine|
Secondary gear ratio
|Clutch||Wet, DDS multi-disc clutch, Brembo hydraulics|
|25CrMo4 steel central-tube frame|
WP-USD, AER 48, Ø 48 mm
WP shock absorber with linkage
Suspension travel (front)
Suspension travel (rear)
Front brake disc diameter
Rear brake disc diameter
5/8 x 1/4"
Steering head angle
1485 ± 10 mm
Tank capacity (approx.)
Weight READY TO RACE (without fuel)