Last year, Suzuki Motorcycles introduced its 2012 RM-Z250 motocross bike virtually unchanged. Although no changes were made, Suzuki has been competitive all year in the Monster Energy AMA Supercross and outdoor Motocross series’. The yellow machine was also our 2012 250 Motocross Shootout winner.
For 2013 though, Suzuki presents a totally reworked RM-Z250. From the engine to the chassis and suspension, the bike is a whole different machine. MotoUSA took a trip out to Suzuki’s supercross test track in Corona, California to see what the new bike was all about. Knowing that throwing down on an ever-so-challenging supercross track requires serious skills, we recruited the help of our longtime test rider and pro motocross ace Chris See as our guy. Upon arrival, we noticed that the track was not in gnarly supercross testing form but a rather toned down version with filled in triples and only a few woops for safety and fun.
Just about everything on the Suzuki has changed this year, so much that by the time I finish typing my fingers may be bleeding. At a glance the RM-Z looks basically identical to the 2012 model with the exception of a black back fender, yellow
Suzuki invited MotoUSA out to its own supercross test track where we were able to spin laps aboard the 2013 RM-Z250.
front number plate and bold new graphics. Beneath its yellow skin is where the real changes are made.
In the bottom end of the engine is a complete new transmission to allow for smoother shifting and ultimately allowing for a quick shift feel. A new crank pin was added allowing it to capture more sludge, also aided by the oil strainer, which better lubricates the engine. More importantly the new crank pin will enhance durability of the crank bearings mostly on the big end. These updates contribute to smoother power delivery and better throttle response.
“I admire the new transmission,” explained our pro test rider Chris See. “In years past I felt the bike shifted very notchy and at times I would need to use the clutch to shift. The new tranny allows for the bike to shift much smoother and faster but most importantly provides confidence for the rider.”
In the top end a 3% lighter piston is added without compromising strength or rigidity. The intake camshaft profile and the exhaust camshaft timing were changed to adjust overall output characteristics resulting in both higher output and controllability. Cooling the revamped engine are redesigned radiators featuring a bypass hose connecting the two, revised hose routing and a changed fin pitch. The updates provide better cooling efficiency which correlates to more stable performance.
“The Suzuki has always obtained a solid engine package geared toward more aggressive riders,” says See. “This year’s engine felt different. It is mellowed out a ton on bottom and picked up a bit in the mid-range and at the same time didn’t lose
The 2013 Suzuki RM-Z250 has received a significant amount of engine updates in both the top and bottom end.
any power up top.”
As far as chassis goes the biggest change for 2013 is the fork. Suzuki has updated its front suspension on the two-five-oh with a second generation Showa Separate Function Fork (SFF). The idea of the fork is to separate the springs and dampening to reduce friction. This results in a weight reduction of 2% and increased absorption performance. The inner tube diameter has been upped in size from 47mm to 48mm for optimized stability and absorption. Spring pre-load is now adjustable allowing for a wider range of settings. Overall results from the new fork result in increased damping force with stronger rigidity and smooth operation.
See explains, “The new Separate Function Fork was an overall improvement to the bike. At first it seemed a bit soft under harsh braking and created a tucking effect in the corners so we stiffened the compression two clicks and sped up the rebound two clicks as well. We then raised the fork 2mm which gave the Suzuki its turn on a dime feel. It was all smooth riding from there.”
The RM-Z frame has received a couple of improvements and updates as well. Changes to the structure of the frame head, tank rail, down tube and bridge tube were made. The material that makes up the engine mounting brackets have changed from aluminum alloy to steel for reduced vibration. These updates add up to more controllable handling characteristics.
The biggest change to the chassis is the new Showa SFF fork, reducing weight and increasing performance.
Supercross tracks require a stop-and-go style of riding meaning fast straights and tight 180 degree corners. A good set of brakes are definitely needed for this and the RM-Z did us proud. The brakes worked perfect all day providing plenty of stopping power, never giving us even the slightest hint of brake fade. The wave rotors along with the sticky Dunlop MX51 tires really stopped the RM-Z on a dime.
In the electrical department the ECM and ignition coil receive new settings aimed at optimizing combustion efficiency and enhanced roll-on performance. The magneto power output now generates 8% more charging performance to improve ease of starting.
Overall, we are stoked to see the 2013 Suzuki RM-Z 250 receive so many changes this year. We think the bike is good, but still aren’t fully satisfied with it, the suspension was still a tad bit on the softer side and we feel like it could use a little more power on top. With that said, testing was only conducted on a smooth and tight supercross track so that is to be considered. As soon as we can get our hands on one again, we’ll be sure to take it out and shred some outdoor style tracks so check back for updates.