Full details emerge of new generation MX2 contender.
After recently unveiling a new generation Suzuki RM-Z250 will be released in 2019, Suzuki has confirmed details of the all-new model that will receive both cosmetic and performance enhances in the new year.
Extracting maximum performance out of the RM-Z250’s powerplant entailed working on every detail possible. This includes a 30 percent larger air filter intake aperture and straighter outlet to the throttle bodies for more air flow, and a redesigned cylinder head intake and exhaust ports that improves combustion efficiency and increased fuel pressure for enhanced fuel/air atomisation.
The RM-Z250’s fuel injection system now features two injectors – instead of using a single injector that can compromise low-end fuelling in order to supply enough fuel for top-end power, the primary injector delivers precise low-rpm fuelling while a secondary injector at higher rpm provides the extra fuel needed.
The exhaust pipe was lengthened by 99mm, with the internal diameter tapering from 35mm at the cylinder head to 45mm at the muffler. Piston durability has been increased by conical machining of the wrist-pin, while to optimise acceleration, second gear was made taller as the rear sprocket was enlarged to a 50-tooth from a 49-tooth unit.
Replacing the previous adjustment-intensive PSF2 air spring fork from last year’s model, the new KYB coil spring fork features a unique design that provides a progressive damping set-up offering excellent compliance over small bumps while firming up deeper into the stroke to handle bigger hits such as harsh jump landings.
Upper and lower triple clamp design has been optimised for rigidity while cutting 60 grams. Out back, the rear suspension linkage ratio has been changed to firm up short stroke movement while optimising longer suspension action for better traction, and is 14.9 grams lighter.
The fully adjustable KYB shock has an improved range of adjustment, and a spring with thinner yet stronger wire (feed back from MotoGP technology) that is 370 grams lighter than before. On an added note, the chain guide is a new design, with a shape that allows the chain to travel through it more evenly to improve durability, while also dropping another 30 grams.
New lighter Dirtstar wheels reduce all-important rotating mass by 40 grams up front, and 60 grams in the rear. For 2019, the RM-Z250 will be fitted with Dunlop’s latest Geomax MX33 tire that has generated rave reviews, with an adaptive design intended for soft tracks that can perform well on medium, sand and mud racing surfaces, too.
Suzuki beefed up the RM-Z250’s front brake for 2019 – the disc diameter has been increased from 250mm to 270mm, and the brake pad material has been changed for more linear response characteristics as you brake harder.
The RM-Z250 is already known as one of the best-cornering motocross bikes available, but Suzuki has improved that for 2019. The frame and swingarm are all new, with the aluminium frame spars changing to a hollow square section that does away with an internal rib, shedding 370 grams while increasing torsional rigidity by 10 percent for better stability and bump absorption.
Using a new hydroforming process for the aluminium swingarm permits a tapered cross-section without any welding, making the new assembly just as rigid with thinner walls for a weight loss of 80grams. In order to increase the RM-Z250’s agility, the engine position was pivoted upward at the rear engine mount by 8.5mm measured at the crankshaft centre.
The upper engine mount brackets are now aluminium instead of steel, and rather than four brackets suspending the engine from a single location, the 2019 RM-Z250 has four brackets on both sides of the engine. This not only drops another 90 grams, but also increases overall rigidity.
The seat rails (which are now hexagonal in cross-section to allow easier air filter access) have been moved closer together for a narrower midsection, while also being raised to ensure adequate airbox capacity. In order to take advantage of the new frame, the seat is all new, with its shape and foam density changed to allow easier movement, all while dropping 274 grams.
The footpegs have been moved 3.3mm forward and 5.2mm upward, while the Renthal Fatbar tapered aluminium handlebar was repositioned 7.4mm forward and 3.8mm down- ward. The Renthal handlebar’s overall bend is also straighter than before to enable the rider to shift weight forward more easily. And the previous aluminium fuel tank has been changed to a resin-based unit, saving another 312 grams.
All the power in the world won’t do any good if you can’t transfer it to the ground, and Suzuki’s innovative electronics work transparently with the rider for maximum acceleration on any type of dirt or track conditions. The 2018 RM-Z450 debuted the third-generation traction management system, with a significantly updated S-HAC (Suzuki Holeshot Assist Control) and more powerful ECM (engine control module).
For 2019, Suzuki’s RM-Z250 goes another step further with the fourth-generation system featuring updated ECU software. The new RM-Z250’s S-HAC monitors throttle position and gear position in order to adjust ignition timing for maximum acceleration through the three critical stages of a motocross start – the exact moment of launch, getting over the starting gate, and then powering up the start straight.
Three settings are available, with ‘A’ mode intended for harder surfaces where controlling wheelspin is paramount, ‘B’ mode for normal dirt conditions with good traction, and an ‘O’ setting.
In keeping with the signature design started by the 2018 RM-Z450, the 2019 RM-Z250 maintains Suzuki’s distinctive styling. Intended to convey the brand’s heritage of speed, the front fender and radiator shroud are arranged to form a straight line, with the sharp and edgy angles expressing a feeling of dynamic speed.
The 2019 Suzuki RM-Z250 is slated to go on sale in Australia during the first quarter of 2019, while its price is still be determined. For more information, visit www.suzukimotorcycles.com.au.