TEST: 2023 Yamaha YZ450F
For the test of the flagship of the Yamaha MX line-up we traveled to the south of France. Once there, we saw the new YZ450F in the hotel lobby. In addition to external changes, the new engine block was also noticeable. What's more: apart from the inverted cylinder + head, you saw little that was reminiscent of the previous model year.
The new YZ450F is designed according to the 'Put the rider first' philosophy. That sounds logical, you might say. However, this slogan is not always self-evident in practice. Just look at the past of the 450 crossers. Every manufacturer was on the hunt for more and more power. Until engines became so powerful that only a few could really do everything with them. And that was not without risk.
This 'Put the rider first' approach also translates into the Japanese way of working. A goal is set and all employees then focus on achieving that goal. The importance of the group is greater than that of the individual. Everyone serves a higher purpose. In Yamaha's view, this means: creating complete harmony between rider and machine. Which makes motorcycles, as it were, an extension of the rider's body and mind. MWith that objective in mind, Yamaha began developing the new YZ450F. Ambitious? And or!
What has changed?
For 2023, the YZ450F's engine has been completely redesigned. Each component was assessed and analyzed. That exercise resulted in the most significant change to the engine since the original inverted cylinder head layout in 2010. Thanks to a forward-facing intake and rear exhaust, this engine layout ensures a high level of driving efficiency. The positions of the airbox, fuel tank, exhaust and the rearward-sloping cylinder also contribute to mass centralization.
The completely new engine is lighter and stronger. More linear delivery for more pulling power and improved handling characteristics make the 2023 YZ450F easier to ride at all speeds, according to Yamaha.
New piston, lightweight cylinder and redesigned crankshaft
The inverted head engine benefits from an optimized combustion chamber, a newly designed piston and a lighter cylinder that improve power and behaviour. To allow a 500 rpm increase in speed, the new engine is equipped with a high-precision, low-friction camshaft chain. For greater efficiency, the crankshaft and connecting rod have been redesigned. A lighter sleeve bearing replaces the previous needle roller design. A new single balance weight features a new hollow balance shaft and this improved lighter design reduces vibration.
Increased air intake volume
For 2023, the highly efficient, forward-facing intake design has been further improved by a reshaped intake port with a straighter passage to the cylinder head and the use of larger diameter 39mm titanium intake valves that increase air intake volume by 9% at maximum valve lift. Complementing the improved intake layout, the shape of the exhaust port has also been revised for a smoother connection to the exhaust.
New air intake routing with vortex airbox
There is a completely new air intake path, with fresh air now routed through the space between the fuel tank, frame, seat and side panels. This redirected airflow prevents water, dust and mud from entering the airbox and results in a lighter and sleeker machine that is more compact. Not only do you see that immediately, but you also feel it immediately as soon as you step on the YZ450F.
The 2023 model also features a high-efficiency airbox design that creates a vortex so that dust is separated from the incoming air by centrifugal forces before entering the new circular three-dimensional filter. In terms of noise, you experience fewer decibels on the engine itself, which is certainly an improvement compared to the previous model.
Newly designed transmission and lightweight clutch
To accommodate the 5% increase in total power, Yamaha opted for a new transmission design. The distance between the driveshafts has been increased and the diameter of each sprocket has been increased to reduce weight and increase the power of the 5-speed gearbox.
The two-piece steel/aluminium linkage of the previous model has been replaced by a durable and lightweight one-piece steel design with disc springs instead of conventional coil springs. This new clutch is significantly lighter and slimmer, weighing 0,75 kg less and with a more direct feel and lighter pull on the lever. Unfortunately, the hydraulic clutch has not yet been introduced. However, it is available as a part in Yamaha's GYTR catalogue.
For greater durability over the wider rpm range of the more powerful engine, the new YZ450F engine features an updated cooling system and a new dry-sump lubrication system. In addition, the timing chain, tension roller and connecting rod are also new.
Redesigned aluminum bilateral beam frame
In line with Yamaha's 'Rider first' approach, the Japanese paid a lot of attention to the frame. This resulted in an aluminum bilateral beam frame that offers a lighter feel, greater maneuverability and improved stability.
To achieve the desired character and behavior of the new chassis, the brand did not do it overnight with the crossed tuning forks. From the geometry, to the specific stiffness balance of each individual part, to the way the components interact with each other, everything is coordinated. A major change for 2023 is the relocation of the connection between the tank rails and the head tube, which is now 15mm lower than before – and the connection between the frame tubes that connects the tank rails to the down tube has been lowered by the same amount.
Other significant changes include increasing the stiffness of the downtube and the pivot area of the crosstube and swingarm – and the new frame now features a 4mm-thick steel engine mount up front with three through-bolts – as opposed to an 8mm-thick aluminum engine mount with one through bolt.
Compact and sleek next-generation bodywork
The YZ450F features an all-new 'Horizontal Movement' plastic that gives the 2023 YZ450F a sleek and sleek new look. Every single exterior panel has been redesigned. The result is a slimmer and more compact unit with a seamless and rounded finish for more maneuverability and more freedom of movement on the motorcycle.
A new fresh air supply route to the intake makes it possible to eliminate the front air ducts. This has allowed the fitment of much more compact radiator shrouds with a reduced width of 50mm, as well as a narrower new fuel tank – providing a much slimmer
The compact front fender is combined with a new shorter rear fender. Together with the new seat, air filter cover and fuel tank, the YZ450F has a flatter horizontal profile and a much shorter front-to-rear length in terms of plastic. New side panels and fork protectors complete the dynamic new look.
Revised rider triangle
The relative positions of the three elements of the rider's triangle – namely the saddle, handlebars and footpegs – have been changed to achieve an ideal riding position for different body types. The seat height has been increased by 5 mm and has a much flatter surface.
This allows you to move easily when entering corners and you also have fewer obstacles to moving in the air. Another improvement is the more rounded profile of the left and right sides of the saddle, making lateral movements of the body easier and more comfortable.
The footpegs are now positioned 5mm lower, increasing legroom by a total of 10mm for taller riders. In addition, the handlebar is adjustable in four positions for a more natural riding position, while the rubber handlebar mounts ensure driving comfort. But I am still sensitive to crooked handlebars, as my crash in session 2 confirmed. Although this is quickly resolved by placing the steering wheel against the steering wheel and giving it a good push.
Updated KYB front and rear suspension valves
New suspension valving improves shock absorption and increases traction. To simplify adjustment, the KYB forks are equipped with a hand-adjustable compression damping adjuster. Previously, the adjustment screw was under your handlebars. Pretty annoying because you always damaged the screw and sometimes the steering wheel. Fortunately, this problem has now been resolved.
For those who don't have much experience with suspension tuning, there is now access to clear information and recommendations about suspension settings via the Power Tuner app. The well-known Yamaha application, which can be downloaded to your smartphone, helps you take the guesswork out of adjustments. Top!
Improved rear brake feel
The rear brake plays a key role in changing direction and entering corners effectively. The feedback you receive as a rider is crucial to maintaining control. That's why the new model is equipped with a new rear brake hose with reduced stiffness that improves the balance of brake input and gives the rider more precise control. Especially for the descending corners, I now felt that the brake could be controlled better. Because the rear brake sometimes felt spongy on the previous generation of Yamahas, you quickly developed an all-or-nothing relationship with the rear brake. An excellent step forward in this area too.
New adjustable traction control system
The use of a new traction control system is another example of how Yamaha is helping riders get the best out of themselves. This electronic control system offers two levels of support and an OFF function. By preventing the machine from completely losing grip, the rider can fully concentrate on the track ahead. Personally, I prefer to drive by feel in these conditions, but that is of course also a matter of what you are used to. It is certainly also a system that you as a rider have to experiment with to find out what works best!
Updated Launch Control system
The Launch Control system has a new 'Rev limit' function that can be set with a maximum speed between 6.000 and 11.000 rpm in 500 rpm increments. This allows you to leave the gate full throttle and concentrate on the holeshot. When the Launch Control system recognizes that take-off is complete, the Rev limit function is automatically disabled. When 3rd gear is reached, the Launch Control system is deactivated. I have tried the launch control myself in different settings. By starting at 8.000 rpm: what felt like idling away. Then I went to 9.000 rpm, which was an improvement, but for me the perfect “launch” was at 10.500 rpm. Of course this depends on your weight, the surface and where behind the fence you start. For the test we could, just like the GP riders, start from a grid.
Reduced weight
Yamaha's designers have analyzed every part major and minor in their mission to make the new YZ450F one of the lightest MX1 machines. Read: measured 'wet', with a full fuel tank.
A new fuel pump, airbox and chain guide contribute significantly to the reduced weight and help centralize mass for greater chassis agility. Even the smallest parts – including the throttle cable, handlebar switches and water pump propeller – have been redesigned to reduce weight to just 109kg with a full tank – a reduction of 2,3kg. This 'diet' was certainly necessary for Yamaha's 450 crosser. Not only to get rid of the bulky feeling, but also to tackle the wide front. Still a point that bothered many drivers. I personally found it - compared to more tailored motorcycles - often an obstacle when turning into the real short corners.
Renewed Power Tuner app
For 2023, the Power Tuner app has been upgraded and features an intuitive 'Quick Tuning' feature. An excellent development because now it is much easier and faster to select the desired engine characteristics. Moving a slider from 'Smooth' to 'Aggressive', it's that simple. This actually gives you 8 mappings to choose from. The new app includes additional features including a lap timer, rpm, fuel consumption, speed and other data. As previously mentioned, there is also a page with frequently asked questions about the suspension. This page does not make you a suspension specialist, but it can help you get started. Both to gain a better insight into how you can adjust the suspension or to brief a suspension specialist about what you want.
Final conclusion
Yamaha has really set new standards with the new YZ450F in terms of handling, power and rider position. They also listened carefully and addressed many old points of criticism, such as slimming down the large radiator shrouds and the air filter housing. Thanks to these adjustments, the engine now sounds a lot quieter. In addition, they also looked carefully at the thermal problems that the Yamahas often had by keeping the oil completely separate from the water pump. In the previous generation of Yamahas this was certainly an issue for people who eagerly used the clutch.
The wide choice of mappings that are already programmed as standard in the power tuner app offer something for everyone. I tried all the maps myself, but I always came back to the second smoothest map. Purely because the engine then gave an ideal power delivery. MC des Costières was a typical, hard French job. So we are curious what works best on a sandy circuit in the Netherlands or Belgium.
The steering behavior improved considerably because the engine is so much slimmer. I noticed how you can more easily navigate the bike in a deep rut and thus maintain better control in the rut. In the air it is now much easier to move on the motorcycle because it really feels like one whole.
Minuses
- Rubbers in the triple clamp, a small fall and your handlebars quickly become crooked.
- Handles, still the same handles after 20 years. Easy to solve with a set of lock-ons, for example
- Hydraulic clutch as standard instead of as a GYTR accessory
Tekst: Ricardo Loos
Photos: Yamaha
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