2021 Suzuki RM-Z250 : WINNING BALANCE.
Introducing the 2021 Suzuki RM-Z250 Guide…
The choice of wise professionals and privateers everywhere, the 2021 RM-Z250 is ready for battle. The agile RM-Z250 combines the sleek, race-ready appearance of the RM-Z450 with a versatile engine and responsive chassis to deliver superior performance. Using Suzuki’s “RUN, TURN and STOP” philosophy, factory engineers have made the RM-Z250 a formidable competitor.
The RM-Z250 has always set the standard as the best handling 250 on the track. Fed by a dual injector EFI system, a center-port cylinder head and an AMA-compliant exhaust, the RM-Z250’s engine delivers strong, usable power through the entire rev-range.
The twin-spar aluminum frame and hydro-formed swingarm carry a KYB-supplied suspension that includes a coil spring fork and a shock with four-way damping force adjustment. Strong brakes and ergonomically shaped bodywork that helps keep the rider in control as the RM-Z250 carves up the racetrack.
Tuning the fuel injection and ignition for maximum performance is easy thanks to Suzuki’s mobile device-based MX-Tuner 2.0 and proven fuel-coupler system that is included with each 2021 RM-Z250. Suzuki’s Winning Balance is on display with the 2021 RM-Z250 as it maintains its own high standard for cornering performance.
The 250 class in motocross doesn’t forgive the slightest weakness. That’s why we’ve designed the RM-Z250 to achieve the right balance of “Run, Turn, and Stop” necessary to win in this ultra-competitive arena. Intensive work by our engineers has once again made the RM-Z250 the leader out of the gate,with a engine featuring increased power across the board and class-leading electronics, a lighter frame and swingarm plus updated suspension for even better handling, a completely new styling design, and a laundry list of other updates to make it the most potent motocrosser in its class. Look out…the RM-Z250 is here!
Motocross models –
As one of the winningest brands in the history of the sport, Suzuki’s motocross machines remain the champion’s choice, as their sleek, cutting edge appearance, powerful, yet reliable engine, and natural ergonomics continue to deliver on Suzuki’s racing identity.
The RM-Z250 and RM-Z450 siblings epitomize Suzuki’s “Winning Balance” philosophy with strong brakes for
controlled stopping power, a wide spread of engine torque with high peak power, and a strong, light, and nimble chassis that remains the class standard for cornering performance and extraordinarily precise handling. Add to that leading ergonomics, beautiful styling and unmatched reliability and you’ve got the perfect race-ready machine.
The RM-Z250 and RM-Z450 return with updated graphics for 2021, as well as the ability to now tune the
electronic fuel injection, and ignition system for maximum performance, thanks to Suzuki’s mobile device-based MX-Tuner 2.0 and proven fuel-coupler system that are included with each 2021 RM-Z250 and RM-Z450. Now you can easily tune your motorcycle to suit track conditions or your riding preference from the convenience of your personal device.
The RM85 returns with updated graphics for 2021 and continues to carry on the powerful tradition of racing
excellence and like its larger RM-Z cousins, the RM85 delivers Suzuki’s renowned handling for both experienced junior racers and rookie riders alike. With its reliable two-stroke engine, smooth power delivery and lightweight handling, the RM85 is the perfect motocross bike for anyone learning to race—and striving to win.
2021 Suzuki RM-Z250 Totalmotorcycle.com Key Features
Superb Engine Performance
– Center-port cylinder head increases output and throttle response
– Dual fuel injector system boosts high rpm power
– Traction management system helps the bike hook up
– Suzuki Holeshot Assist Control (S-HAC) gets you out front
Exceptional Cornering Performance
– Frame and swingarm balances lightness with strength
– Engine placement and mounting aid chassis’ nimble handling
– Coil spring KYB fork provides outstanding performance and easy tuning
– KYB rear shock and linkage deliver remarkable control
– Race-ready, high-grip Dunlop MX33 tires
Controlled Braking Performance
– Large-diameter front brake increases stopping power and feel
– Compact rear master cylinder is designed to prevent mud from collecting on it and from catching on the rider’s boots
– Aggressive new styling from the championship caliber RM-Z450
– Narrow cockpit lets rider move with ease for maximum racing performance
– Suzuki’s MX-Tuner 2.0 is supplied, providing quick fuel injection and ignition tuning through an easy-to-use smart-phone application.
– Fuel couplers are also included for quick and easy EFI tuning
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). From 2019, Suzuki’s RM-Z250 goes another step further with the fourth-generation system featuring updated ECU software.
The 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 “off” setting.
SUZUKI HOLESHOT ASSIST CONTROL (S-HAC)
The RM-Z250 is already known as one of the best-cornering motocross bikes available, but we went to work improving it even more. The frame and swingarm , with the aluminum frame spars changing to a hollow square section that does away with an internal rib , are shedding 370 grams while increasing torsional rigidity by 10 percent for better stability and bump absorption. Using a hydroforming process for the aluminum swingarm permits a tapered cross-section without any welding, making the 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 center. The upper engine mount brackets are now aluminum instead of steel, and rather than four brackets suspending the engine from a single location, the 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 frame, the seat , with its shape and foam density changed to allow easier movement, is all while dropping 274 grams. The footpegs have been moved 3.3mm forward and 5.2mm upward, while the Renthal Fatbar tapered aluminum handlebar was repositioned 7.4mm forward and 3.8mm downward. The Renthal handlebar’s overall bend is also straighter than before to enable the rider to shift weight forward more easily. And the previous aluminum fuel tank has been changed to a resin-based unit, saving another 312 grams.
TOP-SHELF SUSPENSION, WHEELS, TIRES
The 250 class is all about maintaining momentum. This requires handling any and all track obstacles as quickly and efficiently as possible, meaning keeping the chassis stable and providing the rider with good track feel and feedback-without pounding him intosubmission. Whether it’s skipping over a big set of whoops, gassing it over a nasty rut- and pothole-filled straight, or landing from that big jump, the Suzuki RM-Z250 has you covered with KYB coil spring fork and redesigned rear shock and linkage.
Replacing the previous adjustment-intensive PSF2 air spring fork from last year’s model, the KYB coil spring fork features a unique design that provides a progressive damping setup 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 optimized for rigidity while cutting 60 grams. Out back, the rear suspension linkage ratio has been changed to firm up short stroke movement while optimizing 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 but stronger wire (feedbacked from MotoGP technology) that is 370 grams lighter than before. On an added note, the chain guide is a design, with a shape that allows the chain to travel through it more evenly to improve durability, while also dropping another 30 grams.
The lighter Dirtstar wheels reduce all-important rotating mass by 40 grams up front, and 60 grams in the rear. From 2019, the RM-Z250 is 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. The 80/100-21 51M is used in front, and the 100/90-19 57M rear Dunlop is 300 grams lighter.
And finally, all this added speed potential won’t help if you can’t keep the “Stop” portion of the performance triangle balanced, so we beefed up the RM-Z250’s front brake. 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.
MORE POWERFUL ENGINE
Extracting maximum performance out of the RM-Z250’s powerplant entailed working on every detail possible. These include a 30% larger air filter intake aperture and straighter outlet to the throttle bodies for more airflow; redesigned cylinder head intake and exhaust ports that improved combustion efficiency and increased fuel pressure for enhanced fuel/air atomization; a direct throttle linkage for better feel.
But our engineers didn’t stop there. From 2019, The RM-Z250’s fuel injection system features two injectors. Instead of using a single injector that can compromise low-end fueling in order to supply enough fuel for top-end power, the primary injector delivers precise low-rpm fueling while a secondary injector at higher rpm provides the extra fuel needed. Plus, while the primary injector now sprays up at the throttle body butterfly valve for better atomization, the secondary injector’s location up near the air filter allows more time for atomization and cooling the incoming intake charge for more power.
The exhaust pipe was lengthened by 99mm, with the internal diameter tapering from ø35mm at the cylinder head to ø45mm at the muffler. Piston durability was increased by conical machining of the wristpin bore ends to relieve stress on the piston crown. And in order to optimize acceleration, second gear was made taller, while the rear sprocket was enlarged to a 50-tooth from a 49-tooth unit.
In keeping with the signature design started by the 2018 RM-Z450, the RM-Z250 maintains Suzuki’s distinctive “Beak DNA” styling. Intended to convey the brand’s heritage of speed in our off-road bikes, 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. Like the RM-Z450, the RM-Z250 is finished in the Team Suzuki off-road colors of yellow with blue accents, making the RM-Z lineup easily recognizable. And the styling is functional, enabling the rider to shift weight forward or backward effortlessly, with the reduction in cover parts dropping 150.4 grams.
2021 Suzuki RM-Z250 Totalmotorcycle.com Features and Benefits
Fitted with a center-port cylinder head, the fuel-injected, 249cc, liquid-cooled, four-stroke, four-valve, DOHC engine remains proven and reliable.
The engine delivers strong peak power and superb throttle response through the entire rev range.
The cylinder head features a refined intake port shape and finish that fine-tunes the fuel/air charge into the combustion chamber to increase engine output.
A large air cleaner opening is combined with a more direct air cleaner outlet tube path into the throttle body for high-volume air flow.
The fuel injection system has extra-smooth power delivery, high fuel efficiency, superb reliability, and easy tuning capability.
First introduced on the RM-Z250, twin fuel injectors are used to deliver excellent combustion chamber efficiency and increases high rpm power.
The primary fuel injector is at the bottom of the throttle body and sprays fuel at the butterfly valve for outstanding fuel and air atomization. The secondary injector is positioned in the air cleaner inlet duct so the fuel and air have more time to mix and cool before entering the engine.
To feed the new twin-injector system and mix the fuel and air charge for outstanding throttle response, the RM-Z250 uses a high-capacity fuel pump.
The special design of the throttle body eliminates complex control linkage, so the rider feels a more direct connection to the engine.
The intake camshaft profile has more valve lift that the prior generation RM-Z250, increasing power at all engine speeds.
The cam chain tension adjuster and guide have been designed to reduce friction and mechanical loss.
The compact aluminum cylinder is finished with Suzuki Composite Electrochemical Material (SCEM) coating for durability, light weight, and efficient heat transfer.
The machining process at the piston pin holes is changed to reduce stress at the piston crown to increase reliability.
Engine starting remains simple, due to a proven kickstarter and automatic decompression system that works precisely and efficiently (eliminating the need for a heavy and costly electric start system).
The high-flow exhaust system has a longer head-pipe, tapered mid-section, and multi-layer silencer with good flow through the entire rev range, with an emphasis on low-rpm performance.
The exhaust silencer is a four-layer design that enhances performance and maintains compliance with AMA sound regulations.
The resin engine protectors help guard the coolant pump (on the right) and the stator cover (on the left) from debris and stones.
Included with the 2021 RM-Z250 is Suzuki’s MX-Tuner 2.0 that provides the ability to easily adjust the fuel injection and ignition system settings for optional race performance.
– Using a smartphone application that wirelessly connects to the MX-Tuner’s compact transceiver, fuel delivery and ignition timing can be quickly changed.
– The MX-Tuner application can pre-program personalized settings into the ECM that can be activated by plugging in one of the supplied fuel couplers.
– Racers and tuners can easily change settings to match performance-related updates.
– The application can save a number of settings for different tracks or weather conditions, plus settings can be exchanged with other racers.
– Real-time engine data and run-time information are accessible to help you stay on top of bike maintenance.
Suzuki’s proven, easy-to-use fuel couplers are also included to simplify EFI tuning.
– For quick fuel adjustments to suit riding conditions, two couplers are provided. One is for a richer-than-stock and another for a leaner-than-stock fuel setting. Riders can change fuel settings in seconds by simply connecting either coupler to the wire harness.
The RM-Z250 features an evolved and faster traction management system that reacts to engine speed changes quickly. The Electronic Control Module (ECM) continually measures throttle opening, engine speed, and gear position, and then adjusts the ignition timing and fuel injector duration to fine-tune the engine output to deliver the best traction for the riding conditions.
– The RM-Z250’s traction management system is different from a street bike traction control system, as it does not measure rear tire spin. Because the needs of a motocrosser are different than a street bike, this system offers constant adjustment that maximizes traction at all times.
The Suzuki Holeshot Assist Control (S-HAC) is a selectable launch system derived from the factory race bike to help riders’ takeoff from the starting gate for an early lead.
– To aid riders at the moment of launch, there are three stages of power adjustment from the S-HAC system: 1) the moment of initial launch, 2) when crossing the starting gate, and 3) acceleration up to full-speed.
There are three S-HAC modes riders can choose for the best option per their skill level and starting conditions.
Mode A: For hard surfaces or slippery conditions at the starting gate. In this mode, S-HAC alters ignition timing at the moment of launch and the ride over the gate to reduce wheel slip to deliver a smooth takeoff. It also advances ignition timing during this sequence for stronger acceleration. After six seconds or when you reach fourth gear, the system shuts off and returns to normal ignition timing.
– Benefit of Mode A: For novice riders, and/or hard and slippery traction conditions, use Mode A for a more controlled launch.
Mode B: When conditions at the starting gate have better traction, and a more aggressive launch is desired. S-HAC will advance the ignition timing to allow increased throttle response and stronger acceleration off the line. The ignition timing alternation is in a similar sequence as Mode A, but with increased overall timing. One of three conditions will return the ignition to normal operation (whichever happens first): After six seconds or when you reach fourth gear, the system shuts off and returns to normal ignition timing.
– Benefit of Mode B: For skilled riders, and/or good starting conditions, use Mode B for a more aggressive launch.
Base Mode: Standard power launch, no action required on the S-HAC switch.
Transmission & Drive Features
The five-speed transmission’s second gear ratio and overall final ratio matches the engine’s stronger output for outstanding acceleration and top speed.
True to Suzuki transmission standards, the gear shift operation is smooth and precise. Carefully designed parts like the precisely machined shift cam and corresponding gears create a transmission a racer can rely on.
The multi-plate, wet-clutch uses a rack-and-pinion clutch release mechanism for precise feel of the engagement and disengagement points while riding.
The lightweight chain guide is shaped to accurately route the drive chain smoothly.
The RM-Z250 features a frame and swingarm design that continues Suzuki’s reputation for creating the best-handling motocross motorcycles.
The aluminum alloy, twin-spar frame combines cast and extruded sections to achieve superior front-and-rear weight distribution, while balancing strength and weight.
The 2021 RM-Z250 frame is 370 grams (0.8 pounds) lighter but has a 10 percent increase in torsional rigidity as compared to the prior generation frame.
The engine’s position in the frame is rotated up so the crankshaft sits higher in the chassis to further the bike’s nimble handling characteristics.
The rear, upper engine mounts are outboard of the cylinder head to increase rigidity and allow a direct intake path to the engine.
The engine mount material is changed to aluminum, rather than steel, for reduced weight.
The swingarm is shaped using an innovative hydroforming process that maintains strength but weighs 0.6 pounds (270 grams).
The hydroforming process enabled engineers to create tapered swingarm beams that increased rigidity, while reducing heavier assembly welding.
Hexagonal aluminum rails are used on the sub-frame for lighter weight, a slimmer appearance, and easier air filter access.
The sub-frame rails are moved inward to slim the bodywork but are also raised to provide additional space for the larger air cleaner.
Not only is the new sub-frame narrow, but all of the body work is slim, so the rider can move freely in the cockpit, especially during spirited riding.
The KYB-supplied shock absorber has a thin-wire spring, spring guide, cushion rubber guide, and lower link that are lightweight and have better movement reaction. The spring and link weigh a pound (447.5 grams) less than the prior generation’s parts.
This KYB shock has specialized damping force circuits and a refined rear lever ratio to help improve the suspension’s traction characteristics.
The damping force adjusters have a wide tuning range, so the settings can better match the conditions and the rider’s style.
The high-performance KYB coil spring front fork has legs with the same springs and damping force components, so front suspension tuning and maintenance is balanced and easy: a great benefit during frequent riding.
This fork uses a free-piston design that separates air and oil to optimize the damping characteristics. The design also helps control the damping cartridge’s pressure and spring recoil, so the fork action remains supple and precise.
The Renthal aluminum tapered handlebar has a flatter bend with less pull-back than prior models to aid rider control during aggressive maneuvering.
A rigid, but lightweight upper fork bracket complements the front suspension and handlebars.
To improve stopping performance and feel, a 270mm diameter, wave-style front brake rotor and a Nissin two-piston brake caliper are used.
The brake pad material was developed for the RM-Z250 to improve performance. The master cylinder is a push rod type that more effectively transmits the squeezing force that the rider applies to the lever.
The rear brake master cylinder hugs the frame beam to reduce dirt contamination and the chance of the rider’s boot touching it during riding.
The wheels feature black anodized D.I.D Dirt Star rims with a cross-section design that maintains strength while reducing un-sprung weight.
To match the handling potential of the RM-Z250, the wheels are fitted with racetrack-developed Dunlop Geomax MX33. Additionally, the rear tire is nearly a half-pound (160 kg) lighter than the tire used on the prior generation RM-Z250.
Suzuki beak-inspired styling has a sharp front fender and radiator shroud shapes that blend into the frame’s side covers and an upswept tail, to promote the impression of speed while reducing weight and easing service.
The functional styling and the motorcycle’s trim chassis permits a variety of rider positions that facilitate control and comfort.
Compared to the prior RM-Z250, the 2021 edition has ergonomic improvements from the new bodywork, the rider’s footpegs are moved 0.12 inches (3.3 mm) forward and 0.2 inches (5.2 mm) upward, while the handlebar grip position is moved 0.3 inches (7.4 mm) forward and 0.15 inches (3.8 mm) downward, to create a high level of rider-control during competition.
The plastic fuel tank weighs a half-pound less than the prior model’s aluminum tank. Fuel capacity is 1.66 US gallons.
The seat base, inner fenders, and side covers were developed to reduce moisture and dirt from reaching the air cleaner. This helps prevent debris from contaminating the air filter.
The slimmer seat has a specialized foam density to aid the rider’s control of the motorcycle. The seat has a large gripper panel that runs nose-to-tail on the cover.
The Suzuki Champion Yellow bodywork is enhanced with distinctive striping and modern logo graphics that are updated for 2021.
2021 Suzuki RM-Z250 – Totalmotorcycle.com USA Specifications/Technical Details
US MSRP Price: $ 7,899 USD
Canada MSRP Price: $9299 CDN
Europe/UK MSRP Price: £ GBP (On The Road inc 20% Vat)
|Engine||249cc, 4-stroke, liquid-cooled, single cylinder, DOHC|
|Bore x Stroke||77.0 mm x 53.6 mm (3.0 in. x 2.1 in.)|
|Fuel System||Fuel injection, dual-injector type|
|Starter||Primary kickstarter with automatic decompressor|
|Transmission||5-speed constant mesh|
|Final Drive||Chain, DID 520DMA4K, 114 links|
|Suspension Front||Inverted telescopic, coil spring, oil damped, adjustable damping force|
|Suspension Rear||Single unit, link type, coil spring, oil damped, adjustable spring preload and damping force|
|Brakes Front||Disc brake, single rotor|
|Brakes Rear||Disc brake, single rotor|
|Tires Front||80/100-21 M/C (51M), tube type|
|Tires Rear||100/90-19 M/C (57M), tube type|
|Fuel Tank Capacity||6.3 L (1.66 US gal.)|
|Color||Champion Yellow No. 2|
|Ignition||Electronic ignition (CDI)|
|Overall Length||2185 mm (86.02 in.)|
|Overall Width||835 mm (32.9 in.)|
|Overall Height||1255 mm (49.4 in.)|
|Wheelbase||1485 mm (58.46 in.)|
|Ground Clearance||330 mm (13.0 in.)|
|Seat Height||955 mm (37.5 in.)|
|Curb Weight||106 kg (233 lb.)|
2021 Suzuki RM-Z250 – Totalmotorcycle.com Canada Specifications/Technical Details
Type 4-stroke, liquid-cooled, DOHC
Bore x Stroke 77.0mm (3.0 in) x 53.6mm (2.1 in)
Compression Ratio 13.75:1
Fuel System Fuel injection
Starter Primary kick
Lubrication Semi-dry sump
Ignition Electric Ignition (CDI)
Oil Capacity 1.0L (0.24 US gallons)
Transmission 5-speed constant mesh
Final Drive Chain
Seat Height TBA
Curb Mass TBA
Suspension Front Inverted telescopic, air spring, oil damped
Suspension Rear Link type, coil spring, oil damped
Brakes Front Disc brake
Brakes Rear Disc brake
Tires Front 80/100-21 51M, tube type
Tires Rear 110/90-19 57M, tube type
Fuel Tank 6.5 L (1.7 US gallons)
2021 Suzuki RM-Z250 – Totalmotorcycle.com European Specifications/Technical Details
Manufacturer Specifications and appearance are subject to change without prior notice on Total Motorcycle (TMW).