Looks can be deceiving, just take the 2016 Suzuki RM-Z250 for example; it looks exactly like the 2015 model. Under the plastic and styling, however, is an all-new 250F. And that change is most welcome since the RM-Z250 has been untouched for a while and was in need of a spruce-up. The almost all-new 2016 RM-Z250 retails for $7699.
A Big List of Updates
Some manufactures now share the styling and base foundation of their 250Fs and 450Fs. It means they only have to make one style of plastic, as many of the components cross platforms and, if the frames are similar, it saves on manufacturing costs. KTM and Yamaha both do this, and we’re guessing Suzuki is moving in this direction for 2017 as well, with the RM-Z450 rumored to be much different next year. This could explain why the 2016 RM-Z250’s styling didn’t change, but probably will be updated in 2017.
Despite the RM-Z’s familiar exterior, Suzuki’s claim of “all-new” is pretty darn accurate. The engine has 80 new engine parts (check out the cutaway image) aimed at overall power improvement and, of course, increased durability. The piston now has a shot-peen finish while the piston pin has DLC coating to reduce friction. An L-shaped top ring reduces blow-by and improves combustion efficiency. New profiles on the camshafts not only work to widen the powerband but also reduce friction. A lighter decompression mechanism on the exhaust cam reduces mass and when weight is shaved on rotating parts the result is improved power. The intake valves are new and Suzuki claims a more efficient flow of fuel/air mixture. The intake valve face is also now flat, reducing the combustion chamber volume and increasing the combustion ratio slightly from 13.50:1 to 13.75:1.
In the name of shaving weight the crankshaft is lighter thanks to the diameter of the crank wheels being reduced by 0.5mm. Now, with a crankcase change, less of the crank drags through the engine oil, reducing drag and increasing power. Further reducing drag, the casting changes to the right hand crankcase let oil flow away from the crank wheels quicker and increase oil flow. The engine also has a new rotor with a 9% increase in inertia, improving power delivery and complementing the crankshaft’s weight reduction, maintaining the balance of the engine. A Keihin 44mm throttle body still feeds fuel and air to the engine, but the angle of the throttle valve plate (butterfly) in the throttle body is now open 0.5 degrees to reduce engine braking and improve throttle response off idle. A new muffler and a 40mm longer header pipe meet the 94 dB AMA sound limit. A lot of the engine improvements were done so the RM-Z250 would match and exceed the performance of the 2015 RM-Z250 with a quieter exhaust system.
The 2016 RM-Z250 now comes equipped with the Suzuki Holeshot Assist Control (S-HAC), featuring a Mode A and Mode B. Mode A is used for slippery start surfaces like concrete, while the more aggressive Mode B is used when traction is plentiful. Within Modes A and B there are three stages of mapping with distinct timed sequences for launching, going over the gate and full acceleration. Once engaged the S-HAC stays active until the throttle is closed, the bike is shifted into fourth gear, or after six seconds. All the motor changes obliged an update to the ECU mapping as well. The RM-Z250 still features two optional EFI couplers that change fuel mapping in the direction of lean or rich.
The new RM-Z frame was designed for better rigidity and balance while decreasing weight by 2.5%. Utilizing the RM-Z450’s head tube, the new RM-Z250 frame also uses new side beams with wider spaced ribs for extra strength and reduced weight. Also new are the lower frame rails and engine cradle.
The 2016 RM-Z250 is equipped with Kayaba’s PSF2 fork, the second generation of the original air fork. The PSF2 uses an air chamber on each leg and is easy adjust. Stock pressure in each leg is 34.1 psi. The Kayaba PSF2 features compression damping plus both high- and low-speed rebound damping adjustment in each fork leg. The KYB shock is also new and comes with high- and low-speed damping adjustment for both compression and rebound.
Out In the Dirt
Suzuki’s revisions for 2016 created a freer revving engine with added power. The new exhaust is quieter, but emits a throaty deep note. Without a 2015 on hand to compare it to, we feel the 2016 might be slightly down on power right off idle, but once into the mid- and top-end the new RM-Z250 has more power. As a welcome bonus the 2016 pulls harder all the way to the rev limiter, allowing riders to stay in each gear longer and requiring less short shifting when compared to the 2015 RM-Z250.
The stock coupler works well on the RM-Z250 and while at Pala and other tracks we tried the lean fuel coupler (white), which increased the response and power off idle and provided a little more grunt all the way to the rev limiter. Some riders felt that the lean fuel coupler didn’t rev out quite as far as the stock fuel coupler. The rich coupler (gray) mellowed out the power delivery but does provide more overrev than both the stock and lean fuel couplers, appealing to faster tracks and more open riding styles. We will play with the S-HAC launch modes as we get more testing time on the RM-Z250.
Suzuki eliminated the RM-Z’s hot start knob, claiming that through cam design and mapping the bike starts easier and doesn’t need the hot start feature. We found the 2016 RM-Z250 didn’t like to start unless a nice full kick was used, requiring the rider to find TDC, come back up and then kick through a full stroke. It isn’t nearly as easy to start as other 250Fs.
With a full day at a not very rough Pala Raceway and a few hours at a smooth Milestone, the KYB suspension has shown smooth action and overall good balance. More time testing at much rougher tracks will reveal its true performance. So far the 2016 RM-Z 250 has a more comfortable feel and isn’t as harsh feeling as the 2015. A great starting point on sag is 105mm and the stock fork pressure of 34.1 psi is great for riders up to about 165 pounds. Faster and heavier riders will want to play with air pressure in the fork (adding a few psi) but overall the handling of the 2016 Suzuki RM-Z250 is balanced and predictable. Even though the bike is quite a bit different, the new frame retains the geometry from 2015, which means it’s still amazing in the corners. The front wheel has tons of bite and it doesn’t matter the type of turn, the RM-Z250 will carve right through it.
We are stoked to see a new RM-Z250 and the 2016 changes improved handling and increased power. Unfortunately in a class where horsepower is king, the Suzuki RM-Z250 isn’t wearing the crown just yet. Styling updates would have helped to drive home the message to consumers that this is an all-new RM-Z250 for 2016. Riders not only want improvements to handling and power, they want their new bike to look new and different as well.
Second Opinion – Kai Mukai – 5’5”, 140 lbs – Pro
My first few days of riding the 2016 RM-Z250 have been good. It has a lot of changes and it took me a while to play around with the air fork settings and all the new adjustments on the shock. The front of the bike has a very light feeling, which sometimes makes it feel twitchy on the front end. The shock felt a little soft at first but with an increase in compression clicks and slowing down the high speed it made an improvement. I want to play with gearing because it feels slightly off. Most turns I use second gear, if I come out in third it takes too long to pick up speed and requires more clutch use. I liked the aggressive (lean) fuel map the most. It gives it a little more power from the bottom to the mid and maintained good overrev. The amazing thing about the 2016 RM-Z250 is how it corners so sharp and precise.
• Increased power for 2016
• Better overall balance
• Stills corners like a Suzuki (excellent)
• Lacks a some hit off bottom
• Picking about starting
• Same Styling as 2015
HS rebound-16 clicks out
LS rebound-15 clicks out
Compression- 7 clicks out
HS rebound-17 clicks out
LS rebound-11 clicks out
HS compression-9 clicks out
LS compression-10 clicks out
2016 Suzuki RM-Z250
Engine: 249cc single-cylinder, four-stroke
Bore x Stroke: 77 x 53.6mm
Compression Ratio: 13.75:1
Fuel System: Keihin 44mm throttle body
Clutch: Wet Multi-Disc
Front Suspension: 48mm KYB PSF2 fully adjustable, 12.2 inches of travel
Rear Suspension: KYB fully adjustable, 12.4 inches of travel
Front/Rear Brakes: Disc Brake 260mm/240mm
Front/Rear Rims: 1.60 x 21”, 2.15 x 19”
Front/Rear Tires: 80/100-21; 100/90-19 Dunlop MX52
Wheelbase: 58.1 inch
Ground Clearance: 13.6 inch
Seat Height: 37.6 inch
Tank Capacity: 1.7 gallon
Weight, Approx: 234 pounds (claimed)
- The all-new 2016 Suzuki RM-Z250.
- It might not look different but the 2016 RM-Z250 is almost entirely new.
- The 2016 Suzuki RM-Z250 has more power, especially up near the rev limiter.
- New to the Suzuki RM-Z250 is the KYB PSF-2 air fork.