No one expected 2010 to be such a big year for Suzuki.
Suzuki Dirt Bike engineers have been busy dialing in and improving on its big RMZ450 MX bike. Modifications to the 2010 RM-Z450 engine include revised cam profiles, cylinder-head porting, and an improved camchain tensioner. Suzuki also optimized the RM-Z450’s electronic fuel injection, reversing the throttle valve movement. Changes to the chassis include a two-piece head stock that’s 9mm-taller than last year. The Showa 47mm forks have new spring rates. The extruded and cast members on the rear section of the frame are now wider, and the motorcycle’s wheelbase is 0.6-inches longer. The Showa rear suspension features revised spring and damping rates.
Suzuki Dirt Bike engineers have carefully developed the RM-Z450’s powerful 449cm3, DOHC, 4-valve engine to increase power throughout the rev range. Always known for its incredible midrange, the 2010 RM-Z450 now has arm-stretching high-rpm power. A combination of revised cam profiles and reworked cylinder-head porting give the 2010 RM-Z450 amazing idle-to-redline thrust. An improved camchain tensioner provides more consistent performance. Also a modified throttle linkage makes the low-speed throttle response more progressive.
Improved Fuel Injection: For 2010, the RM-Z450’s electronic fuel injection is improved with a reversed throttle valve movement. Such a simple alteration pays handsomely: The fine fuel-air mist from the 12-hole fuel injector is directed away from the throttle valve for a more uniform mixture producing increased power and enhanced throttle response.
Chassis Dynamics: Everywhere you look, the RM-Z450’s twin-spar aluminum alloy frame has received detailed improvements to optimize rigidity & balance. It starts with the head stock, which is now a two-piece design that’s 9mm taller than before. The sections at the rear of the frame, which are made up of extruded and cast members, are now wider for increased rigidity. More strength comes from a wider upper frame bridge beneath the saddle, while material wall thickness was strategically designed to save weight.
High-Quality Showa Suspension: The RM-Z450 employs race-bred, state-of-the-art Showa suspension front and rear. For 2010, both ends of the bike are given suitably revised spring and damping rates. The new rates work together with the chassis’ optimized rigidity balance to improve handling. Showa 47mm inverted forks provide optimum wheel travel and can be adjusted for compression as well as rebound damping. A Showa rear shock offers both high- and low-speed compression damping adjustment along with rebound damping and spring preload adjustments. Working through Suzuki’s rising-rate linkage system (now with revised link-bearing tolerances for precise handling performance) the shock provides 310mm of wheel travel while delivering maximum traction.
2010 Suzuki RMZ250:
The rumors are true. Suzuki Dirt Bikes engineers beat everyone to the punch, being the first of the Big Four to fuel-inject its four-stroke 250cc motocross motorcycle. You heard right. The 2010 RM-Z250 is now fuel-injected. Controlling the flow is a 43mm throttle body with progressive throttle linkage that is powered by a magneto-generator. It has been adapted from the system established two years ago in the RM-Z450. The radiator louvers have been redesigned to direct more air to the twin side-mounted aluminum alloy radiators and keep the new EFI engine running cool.
The implementation of fuel-injection, of course, brought about a few modifications to the engine. The core of the DOHC 249cc four-stroke remains the same, but it has undergone revised cam timing and updated intake ports. Suzuki Dirt Bike engineers also went with a stronger connecting rod with mirror finishing and modified the crankshaft. The desired result of the changes is to give the 2010 RM-Z250 more pull up top, which will be helpful since the switch to EFI has also added five pounds to its curb weight, up from 225 to 230.4 lbs.
Suzuki Dirt Bike Racing Technology is everywhere you look: advanced Suzuki fuel injection is fitted for the first time on a four-stroke 250cm3 Suzuki motocross machine. Further engine modifications boost peak power without giving up any of the low-end or midrange that has made the RM-Z250 the choice of top riders everywhere. Chassis updates improve handling with key suspension upgrades making the new 2010 RM-Z250 the perfect weapon for motocross racers worldwide. And there’s the eye-catching slim, aggressive styling that causes the RM-Z250 to stand out at any track.
Fuel Injection: Derived from the RM-Z450’s superlative system, the RM-Z250’s battery-less injection features a 43mm throttle body with progressive throttle linkage, a 16-bit on-board computer and unique capacitor-assisted starting system. A durable, lightweight magneto-generator powers the fuel injection after starting. Because all engine systems are related in performance, a new muffler is fitted to optimize the benefits of fuel injection.
Chassis Updates: In the search for handling perfection, the RM-Z250’s twin-spar aluminum alloy frame has been redesigned with several key components to optimize rigidity balance and improve traction at high speed. The lower frame tube now has thicker walls, 3.0mm versus 2.5mm, while the side rails are slightly shallower. Connecting the 19-inch rear wheel and chassis is a new swingarm design. The redesigned swingarm features improved center brace for increased rigidity/mass centralization for enhanced suspension action and greater traction. To prove that Suzuki Dirt Bike engineers understands the importance of even the smallest details, new footrest brackets are designed to prevent mud clogging.
Updated High-Performance Suspension: Thoroughly revised spring and internal damping rates inside the Showa 47mm Forks and Showa Rear Shock result in improved handling for a wider range of riders. These carefully chosen modifications improve traction and rider confidence at high speed without sacrificing the RM-Z’s legendary quick-turning ability. Modifications to the rear suspension linkage that reduce thrust backlash also improve traction and make for more consistent performance.