Built on championship winning performance, the Suzuki RM-Z450 has seen only minor adjustments for 2017, however the old adage “if it ain’t broke, don’t fix it” definitely applies.
Since 2005, the RM-Z450 has accrued more than 164 race wins and 14 championships in the AMA, MXGP, and AUS series’ with the likes of Ricky Carmichael, Chad Reed, Ryan Dungey, Ken Roczen, Clemente Desalle, and domestically Matt Moss and Todd Waters all showing their true potential aboard what is the winningest 450cc motocross bike of its time.
The last time I rode a RM-Z450 was in late 2014, and fittingly it was a 2014 model bike. Back then the bike was hard to fault and in actual fact that 2014 model RM-Z450 was the reason I stepped up from 250cc racing to the 450cc division. Suzuki developed a platform that catered for club level riders all the way through to the most elite racers and I loved it. Back then I was a huge fan of the overall package of the bike.
The RM-Z didn’t have a particular stand out 10/10 area that shone above all other manufacturers like a ridiculous amount of power, cloud riding suspension, pin-point turning or an unbelievable lightweight feel, but what it did have was the perfect combination of all that main componentry.
The way I like to explain it is, that some manufacturers will have a 10 out of 10 engines but only 5 out of 10 suspension and handling, or vice versa, which means the bike can be quite hard to setup and adapt to. With the Suzuki however, it had a consistent 8 to 9 out of 10 scoring across each area, which is why I liked the bike so much, and why I was keen to put the 2017 model through its paces.
For 2017, the RM-Z450 features a bold new look with black anodised Excel rims, triple clamps and fork caps, as well as black side plates, a yellow rear fender and yellow top seat cover.
As most people know, not much has changed under the hood of the new “Zook”, but why would Suzuki need to when at the same time Ken Roczen’s Soaring Eagle Jimmy John’s Suzuki was converted back to a much more stock trim this year he also returned to his dominating form – coincidence?
For 2017 Suzuki have opted to run the same bilateral aluminium frame as its numerous predecessors. The general specs show a wheelbase of 1495mm, ground clearance of 325mm, and 955mm seat height, whilst also featuring a 125mm trail and 45° steering angle, which sets the balance for the bike.
Complementing the frame is the Renthal Fatbar, rubber mounted bar clamps, lightweight 6.2 litre aluminium fuel tank, and specifically the black anodised triple clamps, which are the same design and make as those currently used by Roczen.
As a package, these chassis components piece together very well to provide a solid foundation for the feel of the bike. Thanks to this foundation I was able to get comfortable almost immediately, and it took only a few small tweaks to the suspension, bars, and levers, to allow me to be fairly content with how the bike could move around.
Personally, I like a motorcycle to have a low centre of gravity feel, which comes from things such as low foot pegs and the suspension sitting a little further through the stroke, but in stock trim without any frame adjustments the RM-Z still managed to tick those boxes.
For the latest model RM-Z450, Suzuki have continued their use of the 49mm Showa Separate Fork Function (SFF) – Triple Air Chamber (TAC) Forks and the Showa rear shock.
In short the Showa SFF – TAC forks are comprised of three adjustable air chambers that eliminate the need for oil and springs. The inner air chamber is the main pressure chamber, which determines the air-spring force in the overall stroke range.
The outer air chamber is the secondary chamber that sets the sub pressure for the mid to bottom part of the stroke. While the balance air chamber, which uses the small gold cylinder on the back side of the right fork leg, determines the air-spring force in the initial part of the stroke range. The great thing about the air fork, is that it’s not only light weight but allows almost unlimited adjustability.
In terms of my personal experience with the suspension, I hadn’t spent too much time riding with air forks previously, so I was impressed with how they felt considering all of the negative talk I have heard about them on other manufacturers machines previously.
I initially spent 15-minutes riding with the dead stock, “out of the crate” fork air pressures, where my first thought was that the forks handled well. After a few laps and getting more comfortable with the bike however, I quickly realised that the forks were too soft. I had a quick chat with the Suzuki technicians and let them know that I like a strong bottoming resistance, with a very plush initial stroke, so with two Psi adjustments I headed back onto the track and put in some more time testing the front end.
I didn’t need to change or adjust the forks or shock for the rest of my time on the RM-Z, and it was only late in the day when I was most comfortable with the bike and began driving it harder into the faces of jumps and turns that I noticed I started to push through the stroke a little more than I would have liked. But again, all you need to do in that situation is bump the chamber pressure up a couple of Psi and head back out to see how it feels.
Suzuki have not made any changes to the engine for the 2017 model RM-Z450, with the same main features as seen over the past few seasons including the three interchangeable ECU couplings, DLC coated piston pin, and Suzuki Holeshot Assistance Control (S-HAC). In particular, the three ECU couplings provide standard, lean and rich air-fuel ratio options, which can be easily swapped to suit the track conditions. The rich coupling produces the most horse power at 53.31 HP, while the lean coupling provides the most torque at 35.8 Nm, with the standard coupling sitting between the two.
After spending a considerable amount of time testing all three ECU couplings back to back, I decided my pick of the bunch was the lean setting. This is simply personal preference and due to the fact that I prefer to run a higher gear and allow the torque of the engine to do the work when riding.
I felt the rich coupling suffered the most in terms of bottom end power, but made up for the initial deficit with a stronger top end rev range, which would be more ideal on a fast, open circuit. The standard setting as you would expect is the perfect moderation between the two in terms of torque and top end power.
Using the lean setting I was able to run second and third gear through most turns without needing to touch the clutch, whereas when running the rich coupling I had to select a lower gear, or feather the clutch to keep the bike from dropping too low in the rev range.
Overall, I would advise to take your time to determine which coupling suits your style best, and remember to keep your hands on the couplings in case you head to a track that suits a setting other than what you typically run.
The other major feature that the 2017 RM-Z450 boasts is the Suzuki Holeshot Assist Control (S-HAC). The S-HAC features three different ignition timing maps – Standard, Mode A, and Mode B. The standard setting has no variation to the ignition timing, while Mode A sees an initial timing retardation, and Mode B sees a completely advanced ignition timing.
My personal preference when testing the three modes was Mode A, as it provided a smooth power delivery, well suited to hard-packed or slippery surfaces, which is what we saw on the starting gates at Toowoomba. Mode B is the more aggressive map and as a result is best suited to sandy or loamy conditions.
Ultimately though, your starting mode selection will vary relative to the ECU coupling attached, so again, spend a little time testing these combinations so that you know exactly what you want when it comes time to ride the bike or get behind a gate.
For 2017, Suzuki have continued their use of a five speed transmission on the RM-Z450, which was faultless in our testing of the bike. The gear ratios and shift feel were both smooth, which come as a result of revised machining processes since 2015. The 250mm front wave disc and 240mm rear wave disc are paired with the Nissin twin and single piston brake callipers respectively, for adequate stopping power. As mentioned above the 2017 model Suzuki also features a bold new look with black anodised Excel rims, triple clamps and fork caps, as well as black side plates, a yellow rear fender and yellow top seat cover to top off the refreshed style for 2017.
As mentioned above, the 2017 model Suzuki also features a new look with black anodised Excel rims, triple clamps and fork caps, as well as black side plates, a yellow rear fender and yellow top seat cover to top off the refreshed style for 2017.
All engine service and self-maintenance information will be available in the 2017 Suzuki RM-Z450 motorcycle manual, but a few handy tips that we were able to score from one of Suzuki’s technicians, include:
Oil is all in one system, with a total oil capacity of 1,100mL with oil filter or 1,050mL without oil filter.
Every six hours / three races:
Replace drive chain.
Inspect oil strainers.
Every 12 hours / six races:
Change oil filter.
Replace piston and rings.
Inspect valve clearances.
Showa SFF – TAC Fork Setup and Maintenance
Thanks to Matt, we are also able to bring you a step by step guide to setup the 2017 Suzuki RM-Z450’s Showa SFF – TAC forks that have been discussed in detail above.
In first setting the RM-Z450 up for fork adjustment, ensure the front wheel is OFF the ground.
Let the balance chamber down to around 120 Psi before setting/adjusting the inner air chamber pressure.
The order in which you should make changes to the air pressure chambers are 1. Inner Chamber 2. Outer Chamber 3. Balance Chamber.
When the RM-Z450 is new, try to first ride the bike with the standard air pressure and clicker settings, then once you have ridden the bike make adjustments if required.
The inner air pressure chamber is effectively the ‘spring rate’ component of the fork, so in theory if you want to move up or down ‘spring rates’ this should be done via the inner air pressure chamber.
The RM-Z450 has regular compression and rebound adjustment on the left hand side fork, which should not be disregarded due to a complete focus on the air chamber pressures.
The RM-Z chassis is very responsive to geometry changes so it is worth experimenting with fork height and setting race sag before jumping straight into varying air pressures.
The recommended race sag (relevant to the rear shock) is 105mm.
As the rear end (shock end) naturally affects the front end more, it is a good idea to set the rear end up before making adjustments to the forks.
The RM-Z450 comes standard with a full workshop manual, which is very handy and has a host of recommendations in the suspension setup area that you can also utilise whenever desired.
It is most definitely advised to always use a high-quality suspension pump, such as the Genuine Suzuki Digital Air Fork Pump, which retails at $137.80.
Once the spring rate (inner chamber pressure) has been set to your desired pressure, this does not have to be adjusted much at all. The remainder of the track to track adjustments can generally be made via the compression and rebound clickers on the forks.
Now that we have covered the setup and fork maintenance, a couple of final key points for the Showa SFF – TAC Forks are:
DON’T try to change the chamber air pressure while the front wheel is on the ground or loaded, as you will get a false reading of the Psi.
DON’T try to ‘check’ the air pressure using the air fork pump gauge, as each time the pump is connected it loses air. So the process you should undertake is to connect the pump, set the air pressure, disconnect the pump, and ride.
The regular retail price (RRP) for the 2017 Suzuki RM-Z450 is set at a very competitive $10,990, see your local Suzuki Motorcycle dealer for more.
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