The 2018 Suzuki RM-Z450 is all-new from the ground up.
New chassis, updated engine and spring forks.
For the first time in a decade, Suzuki has made an all-new Suzuki RM-Z450. Here are the top 20 changes made to the bike:
(1) Revision of the intake and fuel systems.
(2) Suzuki’s Holeshot Assist Control (HAC) has been updated.
(3) New cylinder head port shape increases tumble flow by 25%.
(4) Larger air filter aperture.
(5) Change of injector direction to improves combustion efficiency and throttle response.
(6) A higher fuel pump pressure is used to improve throttle response.
(7) Throttle body has been updated.
(8) A rib has been added to the piston for greater strength to support high engine output.
(9) The frame and swingarm are all new.
(10) The wheelbase is shorter, steering head pipe is 10mm backward and handlebar position is 7mm forward.
(11) New Showa BFRC rear shock.
(12) New 49mm Showa coil spring forks.
(13) Comes standard with Bridgestone Battlecross X30 tires.
(14) The seat has been reduced in weight by 246 grams.
(15) Gas tank material has been changed from stamped aluminium to plastic resin to save weight.
(16) The rear brake master cylinder has been undated.
(17) The rims and upper triple clamp have been lightened.
(18) Chain guide has been updated.
(19) Aggressive new character line with the design keyword “Beak DNA.”
(20) Larger 270mm front brake rotor.
The new aluminium-alloy twin-spar frame combines cast and extruded sections to achieve superior front-and-rear weight distribution while balancing strength and weight. The new frame is 700 grams (1.32 lbs.) lighter to improve cornering performance and shock absorption while delivering stable handling. The new swingarm is assembled with thinner materials for 100 grams (0.25 lbs.) lower weight while cornering performance and handling stability is improved.
A 30% larger air cleaner opening is combined with a more direct air cleaner outlet tube path to the throttle body to increase air flow.
The intake camshaft profile is changed, including more valve lift than the prior model, increasing power at all engine speeds. The compact aluminium cylinder is finished with a Suzuki Composite Electrochemical Material (SCEM) coating for durability, light weight and efficient heat transfer.
The RM-Z450 has a new, Suzuki-unique throttle body design to improve atomization of the fuel/air charge. The new throttle body design eliminates complex control linkage so the rider feels a more direct connection to the engine.
The 2018 RM-Z450 has a relocated fuel injector, fed by a higher-pressure fuel pump that directly sprays fuel at the butterfly valve.
A new plastic fuel tank weighs half-a-pound less than the prior model’s aluminium tank. Fuel capacity is raised to 1.7 gallons. The seat base, inner fenders and side covers were developed to reduce dirt from getting to the air cleaner. This helps prevent debris from contaminating the air filter element.
A new design rear brake master cylinder hugs the frame beam to reduce dirt contamination and the chance of the rider’s boot hitting it during riding.
Suzuki was the last of the Japanese brands to stick with old school 250mm brakes, but for 2018 they have stepped up to a larger 270mm wave-style front brake rotor.
A refined 5-speed transmission enables precise gear shift operation. The transmission feel has been improved with a precisely machined shift cam. Specialized machining processes also increase the precision of the matching gears.
Showa coil spring front fork have larger inner tubes and cartridge rods for durability. Springs in each fork leg are combine with larger adjustable damping cylinders to deliver better response to the terrain. Their is a 3-pound weight penalty in the switch from air forks to spring forks for 2018.
Renthal aluminum tapered handlebars have a straighter bend that prior models to help aid the rider during aggressive maneuvering. A new, lighter top triple clamp is used to complement the new front suspension and handlebars.
The fully adjustable BFRC shock controls damping better during small suspension movements so that ride comfort at low speeds is improved, while stability is enhanced at high speeds.
The 2018 RM-Z450 uses Showa’s Balance Free Rear Cushion (BFRC) shock that has separate, external damping circuits that improves the responsiveness of damping force for better absorption over bumps.
The 2018 RM-Z450 has stronger brakes (for better stopping power), a wider spread of engine muscle (with higher peak power), a frame that is stronger and lighter, and ergonmics that are thinner, flatter and more comfortable.
Instead of an aluminum tank, Suzuki switched to a plastic resin material to save weight. 
