The 2024 Yamaha YZ450F not only has a lighter design but it’s also the slimmest it has ever been. We take it for a spin to find out how good it is!
The power of the YZ450F has always been extremely strong but it has always felt a bit heavy to steer around the track. Straight line stability was always Yamaha’s greatest attribute but getting it to steer in tight ruts was always a fight. That has changed on the 2024 Yamaha YZ450F.
The radiator shrouds are slimmer and the air box cover is 15mm lower making the seat very flat and seamless. The bilateral beam frame is designed and built with tuned flex and rigidity that consists of more than ten aluminium components welded together. The air filter and Keihin throttle body is situated directly above the intake port so that the port has a direct line straight over the 39mm titanium valves. The engine is fitted with a forged aluminium piston and the transmission is a compact five speed transmission with a tri-shaft layout that directly stacks the transmission shafts for a more compact assembly.
The clutch is cable operated however it is a diaphragm spring clutch instead of the coil spring type we are used to seeing on the older YZ’s and uses a one piece steel clutch basket like the design we have seen in KTM’s for several years. The front fork is the highly rated KYB closed cartridge speed sensitive fork that we have seen on the YZ’s since 2005. The big difference with this fork now apart from internal valving and spring settings is the tool-less hand operated compression adjusters located on top of each leg.
On the rear is the fully adjustable KYB link type monoshock. On paper this is the best bike Yamaha has ever given us, so we decided to take one for a few weeks and put it through a few tests to see how it holds up. First we are going to ride it then we will race it. Lastly we are going to stick it on the dyno and see just how much power this YZ450F motor can produce.
What’s New?
- Revised cylinder head layout, forged aluminium piston, titanium valves, lightened crank assembly and dry sump lubrication.
- Optimised intake path allowing the air box cover to be lower with narrower radiator shrouds.
- Refined chassis with revised suspension valving.
The Power Plant
The engine on the YZ produces loads of grunt. The power is earth-shakingly strong. Turning the throttle on this bike can literally overcome gravity but the strangest part of all is that the power is manageable.
Typically in the past the YZ engine has been so aggressive that it was difficult to tame. Any wheel spin and the RPM’s would spike leaving you death gripping the handlebars. For 2024 the power is absolutely no less than it has ever been but the power is broader, smoother and far more manageable meaning actually getting the power to the ground is easier than ever. It’s all well and good to have loads of horsepower but if you can’t actually get traction and get the power to the ground then it is completely useless.
This is by far the best overall engine that Yamaha has ever given us, so much so that I think making it better with the Power Tuner App will be nearly impossible. The gearbox all fares well and the gear ratios are certainly a hit. The new steel clutch basket definitely makes a lot more noise inside the engine but has a very precise feel even though we are still stuck with a cable operated clutch.
We have had trouble in the past with Yamaha electric starters tending to turn over for thirty seconds or more before the bike actually starts but the electric start on the new YZ seems to work just perfectly. The electronics that come with this engine are certainly an added bonus but myself being old school I prefer to do away with launch control, traction control and all that new age fancy electronics and just control the power to the ground with the clutch and the throttle. I’m old and I grew up in a time when traction control was a fairy tale but the new generation of riders that are growing up with this equipment will absolutely see benefit in it and will learn to use it to their advantage.
Steering and Handling
The old YZ’s were like wrestling a fire breathing dragon. They had so much power that they were hard to handle. While the new 2024 model has just as much power, the power curve is far more manageable and far more useful. Pair that with a chassis that is feels entirely different to any YZ I have ever ridden in the past and we have the greatest bike Yamaha has ever given us.
The YZ has entirely different characteristics to any other YZ I have ridden in the past. It no longer feels like a big heavy bike that you have to fight to steer. It feels light and nimble and is one of the best steering production machines I have ever thrown a leg over. Usually a good steering bike lacks high speed stability but Yamaha have figured out a way to keep the high speed stability of the older models and paired it with a new model that can carve the tightest of ruts with ease.
The entire chassis is very predictable. No matter what you hit it never throws you a curve ball. The stability and balance is perfect and the suspension is tuned very well for the masses. I did find I had to stiffen it up a little when I got onto some rougher tracks with skilled riders but the valving will suit the majority well.
I spent some time playing around with rear sag heights and come to realise the YZ works best with a sag height of 105-110mm. If I got the sag any closer to 100mm I found the rear sat too high in corners and would affect the steering so this is important to note for anyone setting up a new YZ. The brakes work well but I did notice the front brake becoming a little spongey towards the end of a thirty minute moto on some faster tracks were I was braking hard downhill. I simply compensated that by adjusting the lever out further and it never really bothered me again.
The Verdict
This is the best YZ that Yamaha has ever given us. It does everything better than any YZ I have ever ridden in the past. It corners better, it’s easier and more effortless to ride. The suspension is predictable and precise.
The motor is an absolute powerhouse while still being easy to control and manage. The bodywork is seamless and flat allowing plenty of room to move around on without getting hung up on any plastics and the rider position is perfect. We are seeing a new style of standing on the balls of your toes while keeping your knees behind your toes coming out of the US at the moment. Our own Aussie Jett Lawrence really being at the forefront of this style and I feel that the YZ really lends itself to promoting that technique with the foot peg to handlebar position.
I would quite comfortably go as far as saying this is the best production bike I have ever had the privilege of testing but with other new models for 2024 still yet to hit our shores time will only tell whether it will stay that way or not.
For the full feature, check out issue #531 of ADB.
WORDS MAT BOYD
PHOTOS JOSH EVANS