Click here for the video from our test session

You only have to take one look at professional racing results sheets from around the globe to realise that Suzuki is onto a winner with its RM-Z motocross range, winning championships both here in Australia and abroad.

When Suzuki first released its electronic fuel-injection system on the 2007 model RM-Z450 it went on to win the MX1 Motocross World Championship with Steve Ramon, and since then it has been a successful few years for the manufacturer.

Last year was yet another stellar year for Suzuki as Chad Reed and Matt Moss won the Pro Open and Pro Lites classes in Super X, the Australasian Supercross Championship, signifying a very solid season for the domestic team.

In 2009, Reed went on to capture the American AMA Motocross National title, while Moss proved the dominant force in the Australian MX Nationals to claim his first outdoor title in the Lites class.

With results like these, development from Suzuki has been fierce with the greatest riders and teams in the world, and for 2010, the production versions of Suzuki’s motocross weapons are reaping all the rewards.

Moss has already debuted on the brand new RM-Z250 at the opening Super X round with a hard-fought victory despite having limited testing time, proving that the EFI system that’s been introduced for the 2010 model is just as beneficial on a Lites class bike.

Riding off the back of their racing success, Suzuki launched its new models at Barrabool in Victoria yesterday, giving Australian media representatives the opportunity to put the yellow missiles through their paces on one of the country’s greatest motocross tracks.

All eyes were on the stunning new RM-Z250 and its EFI, while the 450 also copped its fair share of attention as it stands tall with development direct from Reed over the last 12 months.

SUZUKI RM-Z250 RIDE IMPRESSION
Watching Matt Moss pound out laps of a motocross track can be one of the most beautiful sites in the world, but watching him do it aboard a completely stock RM-Z250 at Barrabool had tongues wagging during the lunch break at the launch.

If it had numbers on it and the Rockstar Motul Suzuki’s customary gold wheels you’d be forgiven for arguing that he was on a factory bike, but in reality, the talented current Super X and MX Nationals Lites champion was doing what he does best on a standard production machine.

With us mere mortals aboard the bike is just as impressive, although we can only leave his pace to our imagination, lapping it up on Suzuki’s brand new quarter-litre king.

The RM-Z250 note is noticeably deep on start-up with a strong bark extracted from the standard exhaust, signifying that there’s a whole lot of motor bolted within the chassis ready to impress.

Starting the bike is simple wether it’s hot or cold, and the right handlebar-mounted hot-start lever also assists in kicking it over in the event of a mishap out on track mid-race.

On track, there’s no doubt that this is the most powerful production 250F that we’ve tested so far for 2010, featuring a strong amount of power from the bottom-end, through to the mid-range, and up in the top-end.

Off the bottom there simply isn’t any sign of bogging as you apply the throttle, with the responsiveness of the EFI engine as impressive as you’d expect, without losing any of the grunt from the previous carburettor models.

You can maintain higher gears and increase your rolling corner speed to power out of the turns with a good amount of power on tap, only shifting back to second in the tighter stuff if you’re really looking to burst out of the corner that bit quicker. It pulls strong in almost any gear.

The gearbox actuation is smooth and 100 percent precise, while the hand and foot controls make for a comfortable ergonomic package that has you sitting flat on the seat, making it easy to move around as you hold tight on Renthal’s tapered standard handlebars.

Over-rev of the engine is impressive as some of the straights permit holding it in third as it increases toward the 13,500rpm limit, or you can simply click another gear and it will also pull hard toward the next corner.

Overall, Suzuki has produced an incredible engine for the RM-Z250LO, an engine that you can see even the domestic race team is excited about with a 2.6 horsepower increase in standard fashion over last year – without compromising power at any point in the range.

The chassis is just as impressive as the steering enables you to place it where you like on the circuit at almost any given moment, with the Showa suspension also responding very well to changes on the clickers.

Suzuki has been recognised for the agility of the RM-Z range in recent years, but perhaps the biggest standout on the 2010 RM-Z250 is its tractability on hard-pack surfaces.

Down some of the steep rolling hills at Barrabool, the traction and connection between the throttle, rear shock absorber, and tyre is sensational as you literally feel the rear squat and the tyre grip to the surface – a feature of the bike that helped Moss in his decision to switch to the 2010 model for Super X so soon.

A loamy sand section with a lot of bumps also gave the new bike the chance to shine in the rough stuff, and through there it is obvious that Suzuki has tested the bike on a range of surfaces before its release.

It will start to go out of shape as you bounce from one bump to another, but stability stays high, giving you to confidence to go that touch faster lap after lap. In fact, riding the standard RM-Z fast is extremely inviting, withstanding hard landings and inspiring confidence on a track that has both high- and low-speed sections throughout.

The Suzuki weighs in two kilos heavier than the Honda, the only other fuel-injected 250F, and it does feel slightly weightier to manoeuvre, but the extra power makes that factor not a worry for the RM-Z.

Braking offers plenty of feel with only slight amounts of fade after the quicker testers got their hands on them, requiring just a slight adjustment of the lever to place it back exactly where you need it.

We might not have been able to lap like Mossy at Barrabool, but the performance of the new RM-Z is a massive step ahead for the yellow team again, taking its EFI system and surrounding it with a solid overall package.

It looks good, goes great, and features the lowest recommended retail price of the top-line Lites class contenders. I have a feeling that Suzuki is going to have a lot of success with this model, both on the race track and rolling them off the showroom floor.

SUZUKI RM-Z450 RIDE IMPRESSION
Open class motocross consumers are looking to make the most of their investment by getting a lot of bang for their buck in the guise of good performance in both the engine and chassis stakes.

When the competition is as tough as what it is in the current 450 class of 2010, Suzuki has continued to build on its model from last year, making refinements to good effect on the very bike that Reed rode to the Super X and AMA Nationals titles this year.

The seat height is the same as the 250, the wheelbase is 20mm longer, and it weighs 8.5 kilos more at 113kg, but the steering capabilities of the RM-Z450 is quite impressive in itself.

In sections where you’d think that the Open class bikes would be a handful, it’s actually very stable, with the Showa suspension package on the 450 just as impressive as what it is on its little brother.

You’re more inclined to take sweeping lines on the 450 and using the power to take you the long way around on some of the faster turns, but its agility through the deep ruts that emerged in some of McAdam Park’s tighter sections was a surprise.

The regular comment of testers getting off the 450 was how easy it is to ride, but not because it’s underpowered, more because the chassis package of it is matched superbly for the 450 motor.

Brake-wise, the 450 is on par with the 250 and both feature a touchy rear brake, so adjust that downwards if you’re not a massive rear brake user.

As you’d expect, it’s not as nimble as the 250 and takes a lot more work as the extra weight is easily noticeable, but the power on tap is grunty of the bottom while remaining usable throughout the range.

You can rev it hard or plod along and it’ll work with you, but beware that when you ride it high in the rev range there’s going to be a lot of power there that only the pro riders of this country could take full advantage of.

Compared to previous models, the power is again smoother and the chassis/suspension revisions make it more tractable again, ever improving what started as a brilliant base back in 2007.

As with the RM-Z250, the bike is very gracious ergonomically, and for somebody who doesn’t ride 450s all that often, stringing a few laps together was slightly easier than expected in between the photo and video shoots.

Starting the 450 is more difficult than some of the manufacturers I’ve ridden recently, but a quick push on the hot-start lever will usually do the trick when hot, and its placement on the right handlebar means that you’re less inclined to twist the throttle when starting (a big no, no, on four-stroke motocrossers).

Unfortunately Jake Moss was injured at round one and Reedy’s switched brands for the current Super X season, but given a top rider there’s no doubt that Suzuki will be up front once again this season.

For the masses, Suzuki has produced an earth-moving ride that can perform at a pro pace, or simply be ridden to the level that you’re willing to push to – all raising mile-wide smiles wherever you stand.

SUZUKI RM-Z250 TECHNICAL INFORMATION
Following in the footsteps of the RM-Z450 Open class weapon, Suzuki has produced an all-new RM-Z250 for 2010, being the first production motocross machine announced in the Lites class to feature electronic fuel-injection.

The RM-Z250 has introduced Suzuki’s innovative fuel-injection technology to quarter-litre, four-stroke motocross racing, along with major engine, chassis and suspension developments.

Developed in competition, Suzuki’s RM-Z250 raises the bar again and further builds on the model’s recent racing results.

Compact, lightweight and revving to 13,500pm, the new RM-Z250’s 249cc, four-stroke, single-cylinder, liquid cooled, DOHC power plant is yet another step forward for Suzuki.

Suzuki’s EFI system incorporates a 43mm throttle body with progressive throttle linkage and a battery-less fuel pump.

The engine features titanium valves, an aluminium-alloy cylinder, with Suzuki’s Composite Electrochemical Material (SCEM) cylinder coating, and Suzuki Advanced Sump System (SASS).

Revised cam timing and intake ports have enhanced high-rpm performance, without compromising the Suzuki’s impressive low-to-mid range power and torque, with the bike measured at 2.6 horsepower more than the 2009 model.

The engine also features a new, stronger connecting rod and mirror finishing, and the crankshaft is also stronger and more rigid.

Radiator louvres have been re-designed, directing more air to the twin, side-mounted aluminium alloy radiators.

Making the most of its new fuel injection system and powerplant, the Suzuki is also fitted with a new muffler.

With carefully selected ratios to maximise performance, the RM-Z250 has a five-speed transmission, while a right-handlebar-mounted hot starter makes getting moving quick and easy.

Accompanying the new engine, the RM-Z250 has an updated chassis and suspension system offering superior cornering and tighter line selection.

Redesigned and more-rigid, a lightweight twin-spar aluminium-alloy frame delivers gains in a number of areas, designed to offer better balance and more traction at high speed.

Lower frame tube walls are thicker and side rails slightly shallower, while a new swingarm has a revised centre brace to increase rigidity, with a centralised mass to deliver optimum traction.

A 47mm inner tube, Showa inverted, twin-chamber, cartridge-style front fork offers 22-way compression damping, 20-way rebound damping and 300mm of wheel travel.

The Showa rear shock absorber combines with a revised rear suspension linkage, reducing thrust backlash and improving traction to deliver more consistent performance.

Both the front and rear suspension have revised spring and damper rates.

The front and rear disc brakes have wave rotors for optimised cooling performance and mud deflection. New footpeg brackets prevent mud clogging to maximise rider feel.

SUZUKI RM-Z450 TECHNICAL INFORMATION
Two years after revolutionising the motocross world with its fuel-injected engine, Suzuki’s championship-winning RM-Z450 features a host of upgrades for 2010 yet again.

The new 2010 model has received a range of significant upgrades, including a further improved engine, a new frame and new suspension, in a bid to keep Suzuki at the front of the field.

Further enhancing throttle response and power throughout its rev range, the 449cc, four-stroke, single-cylinder, liquid cooled, DOHC, four-valve engine features a new cylinder head, piston, crankshaft, throttle body, cam shafts and valve springs.

The Electronic Fuel Injection (EFI) system has been improved with a reversed throttle valve movement, directing mist away from the valve to produce more power and enhanced throttle response.

A new, more rigid, twin-spar aluminium frame is accompanied by a new subframe, linkage and rear swingarm, and enhanced, race-bred Showa suspension to help provide sharper handling, improved manoeuvrability and maximum traction, according to Suzuki’s press kit.

With revised spring and damping rate settings at each end, 47mm inverted front forks are fully adjustable for rebound and compression settings, while the rear shock absorber offers fully adjustable rebound, compression and pre-load settings.

The new RM-Z450 also features a new radiator and significant electrical upgrades including ECU revisions.