Suzuki Holeshot Assist Control (S-HAC)Control Mode SwitchIgnition CoilThrottle PositionsensorGear PositionsensorWatch any raceday motocross interview, and you’ll invariably hear “get a good start” cited as a must-do proposition. And getting holeshots is exactly what the latest version of the Suzuki Holeshot Assist Control (S-HAC) is all about. An integral part of the 2018 RM-Z450’s electronics package, the updated 3-stage S-HAC system assesses throttle position and gear selection, and then adjusts ignition timing to optimize engine output for fast launches.
Managing this at lightning speed, with no rider intervention, is nothing short of motocross engineering brilliance. By interpreting throttle and gear positions, S-HAC continuously alters the timing to maximize power delivery during the three critical stages of a start, including: 1) The exact moment of launch; 2) Getting over the gate; and 3) Accelerating up the start straight. Regardless of the rider, the track conditions, or whether the starting pad is dirt, mud or concrete, S-HAC automatically adapts to provide the quickest and strongest possible drive forward. The system returns the ignition timing to normal operation six seconds after launch, when the rider shifts into fifth gear, or when the throttle is closed, giving the rider ample time to bust out of the gate and toward the first turn.
The latest version of S-HAC included on the new RM-Z450 gives riders a choice of three settings which can be quickly selected via a handlebar-mounted switch. The “A” mode is programmed for hard surfaces, such as a concrete starting pad, clay or hard-packed dirt where controlling wheelspin is crucial to good starts. For 2018, the “A” mode algorithms are updated to provide even finer control as the throttle is being opened, giving the rider an even better feel for traction in the crucial initial moments of a launch. The “B” mode is for normal dirt conditions. Riders can also select the “Off” setting to retain standard ignition timing.
In motocross, you’ve got to get instantly hooked up – both out of the gate and off the corners – and also blisteringly fast down the straights. To give riders an even stronger winning balance, the redesigned 2018 RM-Z450 engine has more low-end torque, a flatter overall torque curve, faster and yet more controllable throttle response, and more peak power.
It’s all due to a comprehensive suite of intake and fuel-system changes. Inside the airbox, the air-filter aperture is now 30-percent larger for enhanced airflow, and an MXGP-style mudguard helps keep mud and dirt out, contributing to greater engine durability. The outlet tube leading from the airbox to the fuel-injection throttle body is also straighter, reducing intake resistance for increased power across the rev range. The throttle body is likewise revised, providing a more uniform fuel-air mixture to further increase power while providing a smoother throttle feel. Increased fuel-pump pressure strengthens the air-fuel mix for enhanced response, and the elimination of a throttle linkage further improves throttle feel.
Intake-portPistonIntake camshaftThe fuel-injector spray path now aims fuel upward to hit the throttle butterfly valve directly for improved atomization. Inside the intake port, the shape is updated for improved tumble flow of the charge as it enters the cylinder, boosting power at all engine speeds. The intake-port shape is matched to a new high-lift intake-cam profile, which further improves intake efficiency and engine output. Inside the combustion chamber, a new piston-rib design adds strength and durability to match the engine’s higher output. While an updated muffler conforms to the latest sound-control regulations. *
*For US specification conforms AMA-sports sound–control regulations.
For European specification conforms FIM sound-control regulations.
The new RM-Z450’s electronic systems work seamlessly with the rider to get the power to the ground. To maximize traction for conditions, the engine control module (ECM) automatically adjusts ignition timing and fuel injection based on throttle position, engine speed and gear position. The first RM-Z450 traction management system debuted for 2008, and a revised second -generation system arrived for 2013. Now in the 2018 RM-Z450’s third-generation traction management system, a revised ECU has fully 1.6-times faster data processing and 2.5-times more memory capacity than the first-generation system.
Lighter, more rigid and more agile, the 2018 Suzuki RM-Z450 gives riders sharper handling, better feel and more control than ever. Its all-new lightweight frame, swingarm significantly improve turning performance, whether you’re railing a berm or diving into the inside line. The head pipe point is relocated 10mm back, resulting in a shorter, 1,480mm wheelbase while the weight distribution forward for agility and stability.
Seat railPrevious modelNew modelFramePrevious modelNew modelFrame advancements include a more rectangular cross-section for the main spars, improved fore-aft rigidity and optimized overall rigidity, together with a 700g weight reduction. All of which directly increase cornering, shock-absorbing ability and handling stability. Swingarm upgrades include thinner materials for a 100g weight reduction and optimized rigidity, which translates to increase cornering and stability.
Additional chassis upgrades include new seat rails with hexagonal tubing for slimmer dimensions and better rigidity. The revised seat-rail shape also allows more airbox capacity and easier air-cleaner service access, while allowing room for the RM-Z450’s new Showa Balance Free Rear Cushion (BFRC) shock. In the cockpit, a straighter bend for the Renthal Fatbar aluminum handlebar helps riders shift their weight forward for improved cornering. And finally, a lighter chain guide provides more even contact and higher durability, while an engine protector shields the water pump and magneto cover from potential damage.
Front forks upper bracketRear suspensionNew Showa front and rear suspension delivers improved responsiveness and terrain following, enhanced ability to absorb forces, better chassis stability, feedback and terrain feel, and improved comfort. The rider payoff is improved control, quicker lap times and less fatigue under hard training or racing conditions.
Up front, an updated Showa coil-spring fork replaces the SFF-Air fork of the previous-generation RM-Z450. It features ease of daily maintenance for wide range of customers. The upper triple-clamp is also lighter with optimized dimensions. While in back, a new Showa Balance Free Rear Cushion (BFRC) shock shares technology with the new 2018 GSX-R1000R sportbike. The design balances pressure above and below the piston to better control the stroke and smooth out reactions to bumps and chop, even under severe braking.
Lighter wheel rims and new Bridgestone tires maximize grip for improved agility and control in a wide range of track conditions. Finished in durable black for a factory look, the new rims have an optimized cross section, which maintains strength while also reducing critical rotating mass by 70g total. Tires are Bridgestone’s latest Battlecross X30. Developed exclusively for a wide range of conditions, the front 80/100-21 51M and rear 110/90-19 62M knobbies help maximize performance in motocross race track.
The 2018 RM-Z450 has a fresh new look that enhances Suzuki’s already distinctive design theme. The evolution starts with aggressive “Beak DNA,” which projects a dynamic arrow form extending from the front fender through the radiator shrouds. Finished in Suzuki yellow with new team graphics and logos, the most potent RM-Z450 yet is recognizable at a glance. The styling refresh also extends to the seat shape, which makes moving between seated and standing positions easier, as well as shifting weight front or rear. And for racers, easier is always faster!
Motocross is a relentless game, and the technology and training needed for bike and rider to excel are too. Suzuki poured more than 40 years of open-class racebike engineering into the 2018 RM-Z450 to make it the hardest-hitting, sharpest-handling, best-balanced and most rider-friendly production motocrosser in company history. Now get out there and own it.
Professional rider in closed conditions
Bore × Stroke
Primary reduction ratio
Final reduction ratio
Rake / Trail
Front Tires Size
Rear Tires Size
Fuel tank capacity
Oil capacity (Overhaul)
2,175 mm (85.6 in)
835 mm (32.9 in)
1,260 mm (49.6 in)
1,480 mm (58.3 in)
330 mm (13.0 in)
960 mm (37.8 in)
112 kg (247 lbs)
4-stroke, liquid-cooled, DOHC
96.0 mm × 62.1 mm (3.8 in × 2.4 in)
449 cm3 (27.4 cu.in)
12.5 : 1
5-speed constant mesh
2.625 (63 / 24)
3.846 (50 / 13)
Inverted telescopic, coil spring,
Link type, coil spring, oil damped
27.8° / 120mm (4.7 in)
80/100-21 51M, tube type
110/90-19 62M, tube type
Electronic ignition (Transistorized)
6.3 L (1.6/1.4 US/lmp gal)
1.2 L (1.3/1.1 US/lmp gal)
Champion Yellow No.2 (YU1)
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