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2018 Suzuki RM-Z450 | FIRST LOOK

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Suzuki has officially unveiled its 5th generation RM-Z450, all-new 2018 RM-Z450. Suzuki recently went to great lengths to help us learn about the new motorcycle and all of its features. The provided details from Suzuki are below, but before that, here’s an explanation of what the significant changes are and what they mean to the rider. In June, Suzuki brought a group of journalists to Japan and I got to see the new bike up close as the engineers presented the new machine and explained not only the new designs, but the philosophy behind those changes.

For the last few years the RM-Z450 has suffered from less than stellar reviews, in my opinion maybe because of its rigidity. I feel like with a few changes the current RM-Z450 can be a fantastic motorcycle, possibly even make a run for the best in its class; it has a good balance of power, stability and cornering. I have ridden the 2016-2017 models in stock form, and also with different suspension and few chassis changes. To anyone who does own a current RM-Z450, I would say if you did spend the money on these modifications you would certainly get your money’s worth, as the gains in comfort and handling are significant.

During the trip to Japan, Suzuki went as far as offering us a day to ride one of their factory race bikes from the All-Japan series, one of the bikes that has been used to develop this all new RM-Z450. A lot of times you will see a works bike that is somewhat removed from what the next production model will be, however, I was impressed to see the remarkable similarities in the factory race bike and the 2018 production machine.

The engineers at Suzuki looked to improve not just on the rigidity, but on every aspect of the motorcycle. They started by using a product concept they call "The Winning Balance." This focused on making the bike run better, turn better, and stop better; Run-Turn-Stop

“Run” refers to increased engine performance. You can easily overpower a chassis and make a motorcycle almost un-rideable, therefore power characteristics on a 450 are monumental. It was an important goal of the Suzuki engineers to produce more power while still maintaining rideability and control. The current (2017) RM-Z450 engine is good, so Suzuki engineers didn't abandon their current engine design. Instead they refined and improved on what they currently have. Most of the focus was on the engine's efficiency. First they looked at the cylinder head where they were able to redesign the intake port, increasing tumble flow by 25%. Naturally, the new intake port design is going to need more air, so Suzuki complimented this change with a new and much larger air filter aperture. The larger aperture also has a new air boot, helping increase air flow from the air filter. These changes are designed to increase peak power, while also maintaining low-to-mid range power. Updated camshaft profiles are designed to help increase power at all engine speeds. The rider’s ability to control this additional power is managed through a Mikuni throttle body featuring an inverted fuel injector. With an inverted fuel injector, the fuel is released upward and bounces off the throttle body butterfly valve in an effort to increase fuel atomization along with throttle response. This is a design Suzuki has been using on their GSX-R 1000 from as far back as 2000. The fuel pump has been updated with a higher pressure model in an effort to improve throttle response and keep up with the additional air flow. Now that the engine was set to be able to get more air/fuel, in it was going to need to be able to handle the extra pressure. Suzuki went to a "rib," or boxed-in, design piston to get the most power out of this new intake system and also offer improved durability.

All of this is managed by Suzuki's new third generation ECM with 1.6x faster data processing and 2.5x the memory capacity over previous units. The new ECM features an "Evolved Traction Management System" and the "Suzuki Holeshot Assist Control" (S-HAC). The evolved traction management system uses inputs from the throttle position, engine speed and gear position. The ECM processes this information and in turn can adjust the ignition timing and fuel injection to match the specific riding (surface) conditions. For the S-HAC there are A and B modes. Pressing and holing the S-HAC switch for 0.7 seconds will start A-mode. You will know you are in A-mode when the indicator light starts flashing. Pressing a holding the switch for 1.8 seconds will start B-mode. You will know you are in B-mode when the indicator light starts flashing more quickly. In A-mode will restrain the engine speed before the start. Ignition timing is retarded to deliver smoother acceleration as the bike launches from the gate. You would use this mode on hard surfaces or slippery conditions. In B-mode the engine will have aggressive response by advancing the timing. You would use this mod in normal dirt with better traction.

“Turn” refers to higher cornering performance. What is a fast engine if you can’t turn the motorcycle? First Suzuki focused on front-rear weight distribution, designing this model with a weight bias of 54kg/119lb. (48.2%) front and 58kg/128lb. (51.8%) rear. The 2018 RM-Z450 also gets an all new frame and swingarm. Both are designed to improve both cornering and stability. Focus has been made on the frame's ability to absorb shock in an effort to improve rider comfort. The new subframe features aluminum hexagonal tubing, which is said to add rigidity and also give easier access to changing the air filter. Wheelbase has been shortened 15mm/ .6in.to 1480mm (58.3"), seat height is claimed at 960mm (37.8"). They also moved the handle bar position 7mm forward with the intention of quick, nimble handling. The new seat is 246g (0.5lb) lighter and is narrower. This is to help reduce the amount of effort needed to move and shift weight while riding. The RM-Z450's already narrow feel also has a new resin fuel tank that is larger than the previous model holding 6.3L (1.6 gal.) of fuel while decreasing its weight by 275g (0.6lb).

Suzuki was the first to offer EFI on a production dirt bike and now they have another first; they are introducing a Showa Balance Free Rear Cushion (BFRC) shock that is the first of its kind on a production dirt bike. This is significant because factory level racers have had access to this technology for a few years and now everyone else will also. I got to ride the factory bike with one of these shocks and it was fantastic. One of the major features of the BFRC shock is a stable pressure balance by operating under low pressure, which reduces friction inside the shock, and also helps reduce cavitation which in turn reduces heat. This shock uses a double tube design that allows the oil to flow in both directions. The traditional piston on the shock shaft travels in the inner tube. Its sole purpose is to pump the oil through a compression valve and a separate rebound valve located in the shock body. With the new BFRC shock, the oil that is displaced by the shock shaft travels through the outer tube to the underside of the piston. This design creates equal pressure in the shock on both sides of the piston. Equally exciting is the Showa TAC forks are gone; they are replaced with new Showa 49mm twin chamber coil spring forks. These new forks are said to offer greater rigidity, and they have a larger inner cartridge and cartridge rods. The inner cartridge piston is increased 2mm to 25mm and the cartridge rod is increased 1.5mm to 14mm. While the sub tank (upper compression assembly) piston has been increased an astonishing 5mm to 39mm. The standard fork springs are a 5.0N/mm rate.

“Stop” refers to better braking. Most of the manufactures have been increasing the front brake rotor size. Suzuki now offers an oversized style front brake rotor. The rear brake has been updated with a new, stronger, and more streamlined rear master cylinder. The engineers took in consideration how boots rub along the side of the frame and also the master cylinder. This new master cylinder has a larger and flatter surface to avoid boots getting caught in any way.

The RM-Z450 meets the ground with the new Bridgestone Battlecross X30 tires mounted on D.I.D rims (Suzuki had been using Excel rims for decades). The US and Canadian RM-Z450 model specifications comply with AMA sound regulations. Japan and European model specifications comply with FIM sound regulations.

Overall the bike looks clean and well thought out. Since we did get to ride the factory race bike and it is incredibly close to the production bike (and I got to see the production bike) I can say the bodywork, seat, and frame fit well together. It still feels like a comfortable Suzuki: narrow where it needs to be and extends out just the right distance where it has to. It’s more of a traditional look and design while some other manufactures are going with a little more aggressive styling.

We spent about half a day meeting with, listening to, and having a good Q&A with the engineers of this motorcycle. It was great to be able to hear their individual goals and what it took for them to get there. While this is certainly an all-new bike I am glad to say they didn’t just scrap what they already had and start from scratch, as the previous generation RM-Z450 was a good motorcycle and my first impression is the new machine is going to be a good bike.

The following material is provided by Suzuki:

Engineering target

RUN Increased Engine Performance
Greater power output and improved throttle response
Evolved traction management
Updated Suzuki Holeshot Assist Control (S-HAC)
TURN Higher Cornering Performance
All-new frame and swingarm
Improved coil spring front forks
New SHOWA Balance Free Rear Cushion (BFRC)
Renthal Fatbar® aluminum handlebar
New tires
Functional Styling
All-new firm parts for performance
STOP Better Braking Force
Larger front brake disc

Increased engine performance

  • Updates to the intake system
  • Updates Suzuki Holeshot Assist Control (S-HAC)
  • Updates traction management system
  1. Greater power output and improved throttle response
  • Increased maximum power output

Primary changes include a thorough revision of the intake and fuel systems.

  • Increases power output
  • Extends responsiveness at higher rpm
  • Produces greater torque at low rpm

New cylinder head port shape

  • Tumble flow is increased by 25%
  • Achieves higher peak power, while also maintaining low-to-mid range power.

Larger air filter aperture

  • Increases power output at all engine speeds.

Change of outlet tube shape

  • Increases power output at all engine speeds

Throttle body

  • Improves throttle response
  • Improves control characteristics

Change of injector direction

  • Improves combustion efficiency and throttle response

Higher fuel pump pressure

  • Improves throttle response

Intake camshaft

  • Increases power output at all engine speeds

Rib added to piston

  • The rib is added to endure higher peak power.
  • Greater strength to better support high engine output

Muffler

  • American and Canadian specifications comply with AMA sound control regulations.
  • Japan and European specifications comply with FIM sound control regulations.
  1. Evolved traction management system

Traction management overview diagram

Traction management overview diagram

Engine output is controlled to achieve maximum traction matched to the specific riding (surface) conditions at the start of a race.

The system has undergone three major stages of evolution since 2008.

2008 First generation

  • The first MX machine to introduce fuel injection.
  • The concept of traction management was also adopted.

2013 Second generation

2018 Third generation

  • Improve overall performance.
  • The ECM : 1.6x faster data processing and 2.5x the memory capacity of the unit in the first generation

  1. Update to Suzuki Holeshot Assist Control (S-HAC)

Mode Character Good for Mechanism
A Restrain engine speed before race start Hard surfaces or slippery conditions Ignition timing is retarded to deliver smooth acceleration as the bike launches from the gate. (Only during start)
B Aggressive engine response Normal dirt (with better traction) Advance ignition timing (Only during start)
Off Normal - Standard

Multi-function indicator light

  • Fuel injection self diagnosis indicator.
  • S-HAC indicator lights.
  • Engine run time indicator.

TURN: Chassis Design

  1. All new frame and swingarm
    New frame
  • Improves cornering performance
  • Improves its ability to absorb shock
  • Improves handling stability

Suzuki RM-Z450 Frame

Suzuki RM-Z450 Frame

New swingarm

  • Improves cornering performance
  • Improves handling stability

New Seat rail

Shorter wheelbase
(1488mm ⇒ 1480mm)

Change of head pipe point
(10mm backward)

Changed handle position
(7mm forward)

  1. New SHOWA BFRC rear suspension
    The first production motocross bike to adopt SHOWA’s new Balance Free Rear Cushion (BFRC).

BFRC - major features * Stable pressure balance — Cavitation generation is minimized, improving damping responsiveness — Easy to make settings

— Operates under low pressure, which reduces friction

  • Compression side area of load significantly increased — Stable damping force in response to minute stroke input

    — Improved damping responsiveness

  1. Improved coil spring front forks
  • Greater rigidity by larger inner tubes and rod pipes  
  • More responsive by larger cylinder
  • Better feeling of control by larger cylinder
  • Ease of daily maintenance

  1. RENTHAL aluminum tapered handlebar

New seat

  • Weight reduction by 246g.
  • Easy for riders to move and to shift weight.

New fuel tank

  • Change of material (Aluminum ⇒ Resin).
  • Weight reduction by 275g
  • Increased fuel tank capacity (6.2L ⇒ 6.3L)

Suzuki RM-Z450 Fuel Tank

Rear master cylinder
Lighter front fork upper bracket
Lighter front/rear wheel rims
Engine protector
New chain guide
Air cleaner mud guard

  • Improves engine durability
New model Previous model
Overall Length 2175 mm (85.6 in) 2190mm (86.2 in)
Overall width 835 mm (32.9in) 830mm (32.7 in)
Overall height 1260 mm (49.6 in) 1270mm (50.0 in)
Wheelbase 1480 mm (58.3 in) 1495mm (58.9 in)
Ground clearance 330 mm (13.0 in) 325mm (12.8 in)
Seat height 960 mm (37.8 in) 955 mm (37.6 in)
Curb mass 112 kg ( 247lbs) 112kg (247lbs)
Engine type 4-stroke, liquid cooled, DOHC 4-stroke, liquid cooled, DOHC
Bore x stroke 96.0 mm x 62.1 mm (3.8 in x 2.4 in) 96.0 mm x 62.1 mm (3.8 in x 2.4 in)
Engine displacement 449 cm3 449 cm3
Compression ratio 12.5 : 1 12.5 : 1
Fuel system Fuel injection Fuel injection
Starter system Primary kick Primary kick
Lubrication system Semi-dry sump Semi-dry sump
Transmission 5-speed constant mesh 5-speed constant mesh
Primary reduction ratio 2.625 (63 / 24) 2.625 (63 / 24)
Final reduction ratio 3.846 (50 / 13) 3.846 (50 / 13)
Suspension Front Inverted telescopic, coil spring, oil damped Inverted telescopic, air spring, oil damped
Rear BFRC (Link type, coil spring, oil damped) Link type, coil spring, oil damped
Rake / trail 27.8˚ /120mm (4.7in) 27.8˚ /120mm (4.7in)
Brakes Front Disc Disc
Rear Disc Disc
Tires Front 80/100-21 51M, tube type 80/100-21 51M, tube type
Rear 110/90-19 62M, tube type 110/90-19 62M, tube type
Ignition system Electronic Ignition (CDI) Electronic Ignition (CDI)
Fuel tank capacity 6.3 L (1.6/1.4 US/Imp gal) 6.2L (1.6/1.4 US/lmp gal)
Oil capacity (Overhaul) 1.2 L (1.3/1.1 US/Imp gal) 1.2 L (1.3/1.1 US/Imp gal)