2013 Suzuki RM-Z450 & RM-Z250 First Look

June 28, 2012
JC Hilderbrand
JC Hilderbrand
Off-Road Editor|Articles|Articles RSS|Blog |Blog Posts |Blog RSS

Hilde is holding down the fort at MotoUSA’s Southern Oregon HQ. With world-class dirt bike and ATV trails just minutes away, the hardest part is getting him to focus on the keyboard. Two wheels or four, it doesn’t matter to our Off-Road Editor so long as it goes like hell in the dirt.

The 2013 motocross lineup from Suzuki has some exciting changes to the 4-stroke models. The Japanese brand offers the RM-Z450 and RM-Z250 full-size dirt bikes and the RM85 and RM85L for youth riders. The small-bore 2-strokes are unchanged except for graphics. Pricing has not been announced for any of the models.

2013 Suzuki RM-Z450
The 2013 RM-Z450 gets new front suspension, engine upgrades and tweaks to the aluminum chassis.

2013 Suzuki RM-Z450

Kawasaki has been using the Showa Separate Function Fork (SFF) on the KX250F since 2011. Suzuki is taking a play out of the Kawi book by slapping the SFF  on the RM-Z450. Suzuki’s new front suspension is a 48mm unit (previously 47mm) which houses the spring in the right fork leg and the valving in the left fork leg. The big benefit of this design is the ability to alter the spring preload on the front which changes the ride height and affects handling. The fork is also lighter and the single spring and cartridge reduce friction. The 2013 Honda CRF450R and 2013 Kawasaki KX450F both get new a new fork as well, but they employ the Kayaba Pneumatic Spring Fork, making the Suzuki the only SFF design in the 450 class.

2013 Suzuki RM-Z250 separate function fork
2013 Suzuki RM-Z250 engine changes
The SFF suspension holds the spring and
valving in different fork legs. RM-Z250 engine
changes are highlighted in yellow.

The Showa rear shock has updated settings to match the new fork. Engineers also worked on the aluminum chassis to balance the rigidity through frame and seat rail adjustments.

Suzuki also massaged the 450 powerplant. The single-cylinder engine gets a new piston that is 13% lighter for a fast-revving delivery and increased bottom-to-mid power. The connecting rod is also tweaked and the piston pin gets a DLC surface treatment for better durability. Cam timing and lift is changed on the intake to smooth power delivery. The RM-Z450 still makes use of fuel injection and comes with three different couplers that change the fuel settings (stock, richer, leaner). It uses a kickstarter to fire up and runs at 12.5:1 compression ratio.

The transmission gets a reshaped shift cam, stopper spring an drive shaft. As a result, Suzuki claims the five-speed is more precise and solid in gear changes.

2013 Suzuki RM-Z250

The 250 also gets the SFF, transmission upgrades, chassis tweaks and comes with the mapping couplers. The engine gets similar treatment as well, the piston is 3% lighter, with additional changes to the exhaust cams and the clutch cam release is modified for a lighter pull and improved feel. The 250 also gets an improved cooling system courtesy of a new radiator fin and revised water hose routing. 

Dunlop MX51 Geomax intermediate rear tire and Dunlop MX51 Geomax intermediate front tire complete the 2013 RM-Z250 package.

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