First Look: 2007 Suzuki RM-Z250

Check out the photo gallery of detail photos from the Suzuki RM-Z250 intro here.

There's a video interview with Travis Pastrana here.

Suzuki recently hosted an intro for their new RM-Z250, which was dubbed, "Return to Dominance." Suzuki is rightfully proud of their record in the 125 (now Lites) class, claiming that they've dominated it since its inception, with a total of 13 World titles, 12 Supercross and five National Championships. (See the end of the article for the full list.)

To celebrate the launch, Suzuki brought in several of their past champions, including Ezra Lusk, Damon Huffman, Travis Pastrana, and Mark Barnett. Buddy Antunez (who has several Arenacross titles to his credit) was also on hand. The crew from DMXS were on hand to keep the party lively, and did interviews with the previously-mentioned Suzuki crew, as well as Ivan Tedesco (before he was tapped to be a possible replacement for Ricky Carmichael), and also Chris Wheeler and Mel Harris. You have to register on their site (www.dmxsradio.com), but you can check out interviews with all of them.

Over the first couple years of its lifespan, the RM-Z250 was part of a bike co-developed and manufactured by Suzuki and Kawasaki. That plan looked good on paper, especially for models like the KLX/DRZ 110, but didn't always provide for smooth relations once the KXF/RM-Z 250 race machines hit the track and it came time to lay claim to the accomplishments of which bike was faster.

With that agreement well in the rear-view mirror, along comes the 2007 RM-Z250, which is pretty much a new bike from the ground up, with a reworked engine, new aluminum frame, and a host of other changes.

POWERPLANT

The '07 RM-Z250 has SASS…as in a Suzuki Advanced Sump System, which is designed to minimize the engine mass, keep the engine's overall height as short as possible, and keep the spinning mass as low to the ground as possible. That adds up to minimal weight and agile handling.

The aluminum cylinder is electro-plated with SCEM (Suzuki Composite Electrochemical Material)…a race-proven nickel-phosphorus-silicon-carbine coating, which they claim allows faster heat transfer and lighter weight than cast-iron cylinder liners.

The four-valve head has been redesigned with a smoother shape and less side squish for smoother air/fuel intake. It's equipped with titanium valves, 31mm on the intake side, and 25mm on the exhaust. This allows the use of lighter-rate single-coil valve springs which they say helps maintain precise valve control even at high RPMs, even with aggressive cam timing and lift.

The hollow camshafts are machined from forged-steel billets to minimize weight which reduces interial mass. They also feature a carburizing heat treatment to reduce friction.

The powerplant also features a compact breather system to reduce internal air pressure and resistance under the descending piston, to improve durability. The kickstart idler gear features a hollow shaft that's designed to function as a centrifugal separator, since the gear continues to spin after the engine is fired. Blowby gasses are automatically separated from the lubrication oil when it passes through the idler gear. The air is vented to the atmosphere, while the oil returns to the transmission case.

Speaking of transmission, the '07 features slightly closer ratios between third and fifth gears, and wider gears have been incorporated for improved durability. The transmission alos features internal changes from a gear-type shifting mechanism to a link type, which Suzuki claims improves shift feel.

Cooling the 249cc powerplant was a prime consideration, with a improved coolant flow volume thanks to enlarged water pump impeller blades, and larger radiators for approximately a 20 percent increase in cooling performance. The shrouds have also been redesigned to contribute to improving cooling performance.

Finally, on the maintenance side, the oil strainer can now be accessed without having to split the cases.

CHASSIS

As mentioned previously, the frame is now an aluminum twin-spar design, rather than last year's steel frame, and it weighs in at nearly two-and-a-half pounds less than the '06 version.

The swingarm shares some design heritage with the RM-Z450, and features a cast front section, mated to extruded arms.

The front suspenders use the same Showa twin-chamber, cartridge hardware as the RM-Z450, and the triple clamps have been redesigned to provide a more stable feel, especially under braking. They also feature a tapered aluminum steering stem, and rubber-mounted bar clamps for the Renthal Fatbar that comes as standard equipment.

The shock is also the same Showa unit used on the RM-Z450, and features a remote reservoir that's larger than in the past with increased oil flow volume for smoother action.

MISCELLANEOUS

The sides of the seat now feature a gripper material.

Here's Suzuki's list of past Lites, MX2, or 125 Champs.