2017 Suzuki RMX450Z Review | Uncorked and Capable

December 28, 2016

2017 Suzuki RMX450Z Review

After a seven-year hiatus, Suzuki has returned to the off-road competition segment with a bike aimed at both the casual trail-rider, as well as the GNCC racer. The new 2017 RMX450Z picks up where the short-lived 2010 version left off, with several important updates.

First off, in stock trim, the RMX450Z is California Green Sticker legal, and we tested it fully stock in our First Ride review. We found that the stock bike is loaded with potential, but is severely restricted to meet emissions and sound requirements. Suzuki’s design concept was to leverage the proven capabilities of the RM450Z motocross bike with tuning and instrumentation focused for trail and competitive off-road use.

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The RMX450Z is kitted with a 35-watt halogen headlight and LED taillight combination, plus an enduro computer with clock and resettable trip odometers. A conveniently stashed radiator coolant catch bottle is located behind the black plastic skid plate to keep things contained when temps climb. A steel kickstand, tool-free air filter access, and an 18-inch rear wheel round out the off-road accoutrements.

2017 Suzuki RMX450Z torque — 2017 Suzuki RMX450Z Review

We consulted with our staff engineers to find out if we could easily access the RM450Z performance from the corked RMX450Z powerplant. It turns out, power increases can be achieved with simple tools and a bit of knowledge.

Modifying the RMX450Z for closed course competition entails removing the throttle stop, plus the airbox and exhaust inserts. It took me about 30 minutes to remove the 1.6-gallon aluminum fuel tank to gain access to the throttle body, remove the throttle stop, and reinstall the tank.

Only a couple of minutes are required for the baffles in the exhaust and airbox. Leave the USFS-approved spark arrestor alone, as removing it will make the RMX450Z powerplant run lean with the other mods.

Immediately apparent is the ease at which the RMX started and idled after the closed-course modifications were made. Twisting the throttle provided crisp aspiration and a throaty exhaust note reminiscent of the first-wave of modern four-stroke engines. Remember, the motor is based on the 2010 RM450Z, not the current version.

Ergonomically the RMX has a slim feel and a neutral riding position, with the Renthal Fatbar offering an upright, high-leverage bend. With a 37.4-inch seat height, the overall dimensions are ideal for riders six-feet in stature and under, which is especially helpful in technical sections when dabbing and pivoting through rock-strewn terrain is necessary.

Suzuki RM’s are well known for their knife-like handling, and the RMX450Z does not disappoint. Out on the trail, I was impressed by how well the RMX handled, and how easy it was to put the front and rear tires exactly where I wanted them.

2017 Suzuki RMX450Z wheelie — 2017 Suzuki RMX450Z Review

Yes, conditions have been superb in late-December Southern California, but this is one of the best handling off-road bikes I’ve ridden. The clincher is that the RMX is incredibly stable at speed as well, with only minimal headshake when decelerating through choppy sections.

Flicking the bike from side-to-side through snaking trails is nearly effortless, and in the high traction conditions, the lean angles I was able to attain and hold were astonishing—even with the lower-spec Dunlop Sports stock rubber. The operative word that continually came to mind was ‘easy’ and, given the context that this is an open-class closed-course machine, easy is quite an accomplishment.

The 449cc DOHC powerplant is very effective and does not overwhelm the chassis or the rider. The EFI and 41mm Keihin throttle body works well, albeit noticeably lean on deceleration—our own fault for letting it breath more freely.

However, the power is completely usable. There is a linear, smooth delivery from idle all through a meaty mid-range, and up to a very narrow top-end before signing-off. In a perfect world, a little bit of over-rev to allow the rider to a hold a gear a split second longer would help to lower lap times.

The 5-speed wide ratio transmission has a lower 1st and 2nd gears, and higher 4th and 5th gears, compared to its motocross sibling. Shifting and clutch actuation is smooth and predictable, but the clutch lever pull is on the hefty side and the feel a bit vague. Expect a bit of workout before acclimatizing.

2017 Suzuki RMX450Z test — 2017 Suzuki RMX450Z Review

The 47mm Showa cartridge coil-spring fork is sprung and valved for off-road use, and the feeling is definitely one of comfort. When the terrain opens up and the whoops get deep, the front forks can pack up and drop into the trough.

Timing the bumps and doubling and tripling through them is a safer approach than launching in with blind ambition and thoughts of skimming the tops. I found that increasing fork compression by four clicks was a major step in the right direction, and helped to balance the bike.

The shock is fully adjustable, and set up nicely from the factory. It’s skewed toward comfortable compliance that enhances traction, rather that being ready for Supercross obstacles.

With a claimed curb weight of 272 pounds, the RMX is about the same weight as the Yamaha WR250F and Honda CRF450X Green Sticker off-road bikes, though heavier than pure-competition off-road bikes. Fortunately, the RMX450 carries its weight extremely well thanks to a narrow profile that contributes to its light steering.

My list of gripes with the RMX450Z is fairly short and easily defeatable. With a 1.6-gallon fuel tank, I saw the low-fuel indicator light illuminate at 30 miles at race pace. The light warns you when there is 0.4 gallons remaining in the tank. Do the math and that puts the race-range at about 40 miles.

The off-road capabilities of the RMX far exceed the perceived expectations associated with a steel kickstand and flat-prone Dunlop Sports tires. There’s no aluminum kickstand available yet for the RMX, though we expect one to be offered by the aftermarket soon enough. If you’re racing, remove it. If not, just sit tight. Dunlop’s Geomax range is a perfect swap for the stock tires—save the Sports rubber for resale time.

The on-off button integrated into the enduro computer does not automatically shut off, potentially draining the battery if the rider uses the handlebar-mounted kill switch and doesn’t notice the headlight is on.

Fortunately, the back-up kickstarter works well and can resuscitate the engine even when the battery is completely drained. Of course, our knuckles love handguards, but the trend among Japanese manufacturers has been to point the consumer to the plethora of aftermarket options for a more personalized solution.

2017 Suzuki RMX450Z msrp — 2017 Suzuki RMX450Z Review

In closed-course race simulations, we clocked the 2017 RMX450Z on the same level as its more race-inspired rivals from blue and orange bike manufacturers.

It’s worth pointing out that timely winter storms produced some of the best riding conditions we’ve seen in Southern California for quite some time, which definitely helped the RMX’s numbers, so we look forward to conducting a full 450-class off-road shootout in the near future for level comparison.

A motocross bike the RMX450Z is not, and that is one of the reasons it shines so well on the trail and tighter and more technical riding situations. What the Suzuki RMX450Z does best is provide high levels of off-road performance with minimal rider effort, thanks to its impeccable handling and an unintimidating riding profile.

In an age of seemingly infinite horsepower, the differentiator becomes handling and corner speed, and the smart open-class racers know that the key to winning is to be able to beat the course, without the bike beating you first, and the 2017 Suzuki RMX450Z is capable of doing just that.

Photography by Don Williams

RIDING STYLE

Helmet: AGV AX-8 Evo
Goggles: Oakley Airbrake MX
Pants, jersey + gloves: Alpinestars LE Techstar Venom
Body armor: Alpinestars Bionic Tech Jacket
Boots: Alpinestars LE Venom Tech 10

2017 Suzuki RMX450Z Specs

ENGINE

Type: Liquid-cooled, DOHC single
Bore x stroke: 96.0 x 62.1mm
Displacement: 449cc
Compression ratio: 11.6:1
Fueling: EFI
Lubrication: Semi-dry sump; two oil systems
Starting: Electric and kick
Transmission: 5-speed constant mesh
Clutch: Web multi-plate
Final drive: DID 520 MXV4 chain

CHASSIS

Frame: Twin-spar aluminum
Front suspension: Fully adjustable 47mm inverted forks; 12.2 inches of travel
Rear suspension: Fully adjustable, linkage-assisted shock; 12.2 inches of travel
Front tire: 80/100 x 21; Dunlop Sports D742F
Rear tire: 110/100-18; Dunlop Sports D756
Front brake: Disc w/ Nissin four-piston caliper
Rear brake: Disc w/ Nissan two-piston caliper

DIMENSIONS and CAPACITIES