Suzuki’s 2018 motocross big chief RM-Z450 arrives with chassis and engine improvements and a competitive price and their trademark knack…
With significant changes to slim down proportions of the 2018 RM-Z450 it remains one of the most eye-catching motocross bikes around.
Slimmer proportions just scratch the surface of a host of changes for the new model. A Balance Free Rear Cushion (BFRC) rear Showa shock absorber is a big change for 2018 and one which it shares with the GSX-R1000R sports bike.
Suzuki can claim this is the first production bike to have Showa’s race-proven, balance-free shock and as a premium product (if you were to buy it aftermarket) it would be an expensive upgrade otherwise. Newly sprung forks, like we used to enjoy (air forks came, didn’t work very well and have thankfully buggered off) are slightly bigger for 2018 at 59.3mm. They contribute to a more capable bike in the rough, chopped-out sections of track.
The new suspension takes the hard landings better and the overall package grows your confidence as a rider. At speed through rough sections of the Eastern France track at Bitche, the new shock controlled movement better and stayed on the line more often rather than needing muscle and cat-like reactions to keep it in check.
Like all new off road bikes the 2018 RM-Z450 is a better bike overall because it is easier to ride. Chassis tweaks are at the root of the improved feel, especially in the corners. A 1480mm wheelbase is 15mm shorter, plus the headstock is 10mm further back and slightly flatter Renthal bars sit 7mm further forward to make it a sharper handling chassis. They sound small but these are significant changes.
A revamped 449cc, four stroke engine has increased power across the rev-range too. A larger airbox and straighter air intake to the FI unit are major contributors – the new air intake increases “tumble flow” by 25 per cent.
The throttle body on the new motor sprays a more uniform fuel mix to improve power and smooth out throttle response also. It shows on this brilliantly undulating track (think tighter Cadwell Park mountain section on dirt) best of all where different gears can be carried through for longer.
The power to the rear wheel is controlled by a new engine management system with faster processing and a bigger brain. An improved ‘holeshot assist’ function aids fast race starts and three power modes (A and B modes plus off) help you change output for different track conditions. The modes incorporate a kind of traction control system but unlike road-going traction control it doesn’t monitor rear wheel spin. Instead it operates based on programming coded into the ECM to “deliver constant control that maximises traction” Suzuki says.
The 2018 RM-Z450 lacks a couple of details which are hard to ignore alongside rival bikes. An electric starter for starters. Kicking a 450 four stroke takes energy and time which is no major problem until you fall off tired, hot and lack the energy kick it over. It also takes longer and in a race that loses time and places. The clutch is heavier too which isn’t a major issue but over a 20 minute session on track it takes a toll on forearm muscles.
New brakes are stronger, the new resin tank (was aluminium) is slimmer and lighter, helping the 2018 RM-Z as a whole become more agile. Smoother and more tractable power make it easier to ride faster. All good reasons to give it the thumbs up. It is good value for a 2018 bike as well and, of course, it looks awesome.
Engine 449cc, single cylinder, four-stroke
Power 55bhp (est, torque N/A)
Fuel capacity 6.3litres