Cycle News Staff | October 11, 2017
Looking Good!
It’s been 10 years since the Suzuki RM-Z450 got a major facelift and significant mechanical updates in the same year. Finally! But is the new RM-Z450 as good on the track as it looks on the stand?
Many changes were made to the RM-Z450’s chassis. The frame itself is lighter, flatter, narrower and there more bias on the front end. Bottom line? It still turns like its on rails.
Ever since Suzuki introduced the RM-Z450 with fuel injection for the first time in 2008, Suzuki has been slow to give its premier motocrosser a new look. It has, however, seen some pretty significant mechanical changes over the years, but it’s pretty much worn the same dress all this time, making it hard for would-be buyers to get excited about it in recent years in spite it still being a very effective motorcycle on the track. Finally, Suzuki gave the RM-Z450 new threads and a number of important upgrades in honor of its 10th anniversary with EFI. (The first RM-Z450 debuted in 2005.)
Despite its aging looks, the RM-Z450 has remained a staple in the 450 class and a favorite among many. Heck, it won a 450MX Championship just last year (2016) in the hands of Ken Roczen, so, even though it might’ve looked outdated, Roczen proved that it was indeed still very competitive. So, when Suzuki went about giving the RM-Z450 a major overhaul, it was careful not to harm any of its already proven attributes, of which—when you think about it—it had many. Cornering is for sure one of them.
PHOTOGRAPHY BY KIT PALMER
What’s New?
The RM-Z450 is known for its outstanding cornering prowess, and it is for this reason why the RM-Z’s has remained so successful in recent years. After all, they say that races are won in the corners, so why not be on the Suzuki then? And that’s why a lot of people still bought the RM-Z. Still, Suzuki gave the 2018 RM-Z450 a fairly significant update to the bike’s chassis to improve ergonomics and to make it turn ever better but was careful not to not mess with what was an already good thing. After all was said and done, Suzuki came up with a slimmer, flatter and lighter chassis package, which also includes a new and lighter swingarm, straighter handlebars and a lighter seat.
Suspension is all new, too. Coil-spring forks are back. The recent trend towards cheaper-to-manufacture air forks (coil springs are very expensive to produce) just did not work out. Air forks, which are also lighter than spring forks, proved to be far too complex to live with for the average person, and just didn’t perform any better on the track than the more consistent and easier-to-adjust spring forks. Pneumatic forks might’ve been a huge advantage for the manufactures but not for the consumers. As a result, the RM-Z450 has gone back to springs and is now fitted with 49mm Showa forks, which are fully adjustable and feature springs in each leg. Unfortunately, they are approximately three pound heavier than the previous forks.
The RM-Z’s shock, however, is one of the most technically advanced shocks in the business. It feature a new damping system that uses a separate external damping circuit that, according to Suzuki, avoids the pressure variations found in conventional shock absorbers. Suzuki calls it Balance Free Rear Cushion (BFRC); it’s unique to the Suzuki and is said to provide smoother and more consistent damping forces over a variety of terrain, especially over smaller bumps.
Finally, the RM-Z450 has a fresh new look, but a lot more went into it than just cosmetics.
The RM-Z450’s 449cc DOHC engine was also a favorite among Suzuki owners. They liked it for its user-friendly mannerisms, torquey feel and good overall power output. It might not have been the best for digging trenches compared to some of the other 450s on the market, but, for many, its overall usability outweighed what it might’ve lacked in shear brute force. Still, more is always better, right? So Suzuki gave the RM-Z450 a little more overall power while trying to keep its friendly temperament. They tried to accomplish this by giving it a new piston, cylinder-head intake port shape and new intake camshaft profiles, and improving airflow; the air filter opening is 30 percent larger now, so all those air filters that you have accumulated over the years with your RM-Z450 won’t fit the ‘18.
Suzuki also gave the RM-Z an all-new throttle body, which Suzuki says improves fuel/air atomization and makes fuel burn more efficient. The new design of the throttle body allows the elimination of complex control linkages for more direct connection and throttle feeling between the rider and the engine. The end result of all this? Improved power delivery.
Suzuki’s Electronic Control Module, which monitors throttle position, gear selection and engine speed to adjust ignition timing for providing premium traction control, has been finely tuned, as has Made A in the Suzuki Holeshot Assist Control system. (Mode A disengages after 1.2 seconds or reaching third gear; Mode B disengages after 4.5 seconds or reaching fourth gear).
The five-speed transmission has been tweaked just a bit to improve shifting.
To help reduce weight, the fuel tank is now made out of plastic resin instead of aluminum, and capacity is up slightly.
We wouldn’t call the engine “all-new” but it did get plenty of changes resulting in more overall power, yet, it’s still delivered in a user-friendly manner.
Well?
We’ve had the 2018 Suzuki RM-Z450 in our possession for over a month now and have ridden it on a variety of tracks and terrain and have come to the conclusion that the new RM-Z450 is indeed an improved motorcycle in just about every way; however, it’s not a drastic departure from the previous RM-Z450, which isn’t a bad thing at all, really. Suzuki diehards will certainly love it; it has more power, still turns like it’s on rails, suspension is much better, and handling is top notch (like it used to be)—all this while still feeling like an RM-Z450. And again, there is nothing wrong with that. Previous RM-Z450 owners won’t have any troubles adapting to it at all; it’s still an RM-Z450 only better.
Suzuki accomplished its goal of giving the RM-Z more overall power without taking away its friendly demeanor. It still feels torquey and hits with authority off the bottom and pulls strongly through midrange. But when the Suzuki used to sign off, it now continues to pull a little further into the upper rpm range. Power is broader and there is more of it, for sure. Pros, however, are probably going to want a livelier, harder-hitting engine, in fact, one pro rider described it as feeling “lazy,” but for the average rider, the RM-Z450 should hit the mark and be well received. The RM-Z still comes with three (total) couplers to adjust mapping and engine characteristic; we found the lean coupler to work quite well on most tracks. It just gives the bike a little more-lively feel without being too aggressive.
The RM-Z is still rather heavy, but the new, narrower and flatter chassis keeps it feeling fairly agile in the air.
Suspension is a big improvement over the ’17. We flat out did not like the previous Showa SFF air forks the RM-Z used to have, so we are happy to see them go. We’re much, much, happier with the new spring forks that are similar to what the 2017 and 2018 Honda CRF450R use; the new spring forks just have a more comfortable feel, tract better in the turns and are easier to dial in, and they tend to stay that way. Out of the crate, though, they’re set up a little on the soft side for aggressive riding and bottom easily. Our fast riders stiffed up both the fork and shock significantly, and went with 108mm of sag and were pretty satisfied, but they said stiffer springs would be in their future if the owned it.
Except for perhaps being a little on the soft side, the rear shock got nothing but praises from our testers. It does a fantastic job soaking up the bumps, which results in improved control and traction while exiting the turns. One pro-level veteran rider said that it felt better over the square edges than any bike he’s ever ridden, which includes factory race bikes! Suzuki nailed it with the RM-Z’s rear shock.
The RM-Z has always been a sweet-handling machine but now with significantly better suspension, it handles even better. We found the Suzuki to shine on rough tracks with lots of ruts and ever-changing terrain at both high and low speeds.
As you can tell, we’re really liking the new RM-Z450, but we have to admit that we’re disappointed that it’s still relatively heavy and does not have electric starting. The RM-Z was already one of the heaviest bikes in its class; even though it has a lighter chassis, it didn’t lose enough to compensate for the heavier spring forks. It’s still on the bottom end of the list when it comes to weight at 252 pounds (full fuel). It trails the 2018 Honda CRF450R by just a single pound, but the CRF has electric starting and pretty much the same forks! The Suzuki also trails the 2018 KTM 450 SX-F (the lightest bike in the class) by 16 pounds, and the KTM has electric starting as well!
We’re liking the new looks but wish it had electric starting. The fuel tank is now made out of plastic resin instead of aluminum.
And, yes, we’re huge fans of electric starting. There’s no going back; electric starting is here to stay. Kick-starting motorcycles these days is simply archaic and we were hoping the new Suzuki would come with a button, oh well. This omission might be an issue for Suzuki to rectify now, because they just finished making big changes to the RM-Z and are again going to have to make some more big changes to keep weight at a reasonable number if they do decide to add electric starting in the near future. The Kawasaki KX450F is the only other 450 without electric starting right now and it weighs 241 pounds.
Luckily for the RM-Z, it still feels pretty light and agile on the track, so its weight problem really wasn’t a huge complaint at the end of the day with our test riders. But we can’t help but wonder how it would feel sans 10 pounds. Oh man. However, we’d be satisfied with 252 pounds and electric starting.
The RM-Z is a comfortable motorcycle; ergonomics are neutral and pleasant, controls are smooth and light (but clutch pull could be a little lighter), and it has some of the best brakes in the business. The ever-so-important front brake, which now features a larger 270mm disc, is strong and has excellent modulation, though we did notice some fading every so often on long and steep downhills—like the ones at Glen Helen Raceway—late in a moto on a hot day. Clutch also lost some of its crisp feel under heavy use.
The standard Bridgestone Battlecross X30 tires are pretty good, especially in the back, and we’d be perfectly happy to run them till they wore out, then we’d replace them with something else like Dunlop’s MX3s, a good all-round tire that has treated us well in the past.
The new Showa spring forks are a big improvement over the previous SFF air forks. They’re easier to dial in and have better rider feedback.
Overall, we are very happy with the all-new 2018 Suzuki RM-Z450. Like we said earlier, it is indeed an improved motorcycle in every way, just not as improved as we thought it would be; maybe our expectations were just too high because of the long wait for it. Still, the RM-Z a great motorcycle and we’d be happy having it live in our garage permanently. But we’d be even happier if it had electric starting, or at least weighed far less. Still, we’re glad to see that the RM-Z450 has indeed taken a big step in the right direction. CN
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SPECIFICATIONS: 2018 Suzuki RM-Z450
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MSRP
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$8,899
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ENGINE:
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Liquid-cooled, DOHC, 4-stroke, single
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DISPLACEMENT:
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449cc
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BORE & STROKE:
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96.0mm x 62.1mm
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COMPRESSION RATIO:
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12.5:1
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FUEL SYSTEM:
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Fuel-injected, 44mm throttle body
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STARTING SYSTEM:
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Primary kick w/automatic decompressor
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LUBRICATION:
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Semi-dry sump
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IGNITION:
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Electronic CDI
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TRANSMISSION:
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5-speed, constant mesh
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CLUTCH:
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Wet, multi plate
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FINAL DRIVE:
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Chain, D.I.D 520MA2K, 114 links
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FRONT SUSPENSION:
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Showa, 49mm inverted telescopic fork, fully adjustable
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REAR SUSPENSION:
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Showa BFRC, link-type, coil spring, oil-damped, fully
adjustable
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FRONT BRAKE:
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270mm w/wave-type single disc
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REAR BRAKE:
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Disc
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FRONT TIRE:
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80/100-21 in. M/C 51M Bridgestone Battlecross X30
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REAR TIRE:
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110/90-19 in. M/C 62M Bridgestone Battlecross X30
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FUEL CAPACITY:
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1.6 gal.
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WHEELBASE:
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58.3 in.
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GROUND CLEARANCE:
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13.0 in.
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SEAT HEIGHT:
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37.8 in.
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CURB WEIGHT:
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252 lbs. (actual)
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GEAR ID’d
If It Was Ours…
…We’d be perfectly happy racing it as is right out of the crate—at least for a while. Stiffer fork springs would probably be our first mod we’d make to it, and we’d also consider beefing up the clutch a bit, having noticed a hint of fading during our testing, which isn’t unusual when it comes to 450Fs. Otherwise, we’d just put gas in it and ride it.
What Is BFRC?
The 2018 RM-Z450 is the first production motocross bike to use Showa’s new Balance Free Rear Cushion, or BFRC shock. This unique shock absorber is the same design as the BFRC fitted to the GSX-R1000R. The BFRC uses an external damping circuit that avoids the pressure variations found in conventional shock absorbers.
With the damping mechanism outside of the shock body for both the compression and rebound strokes, the BFRC, according to Suzuki, achieves smooth, optimized oil flow. The BFRC is said to deliver enhanced response with better shock absorption over bumps. According to Showa Race Technician Scott Bennett, the BFRC technology responds well to high and low speed suspension movement and reacts to fine movements better, which, he says, delivers smooth action and improved traction.
The damping force valves and adjusters located at the top of the BFRC making for easy adjustment. The large gas chamber capacity stabilizes internal damper pressure and temperature to maintain damping force consistency. The piston inside the cylinder only pumps fluid through a basic and reliable action, which simplifies construction and enhances durability.
