The Yamaha YZ450F has played its part in the success of some of the greatest riders in the history of motocross, most notably ten-time world champion Stefan Everts, 2008 MX1 champion David Philippaerts and 2015 MXGP champion Romain Febvre. The 2020 YZ450F has been subject to some important changes and refinements to the chassis and engine. I [Rob Holyoake] had the chance to ride the new YZ450F at the Teutschenthal circuit in Germany, a staple on the MXGP calendar and host to the Motocross of Nations in 2013.
Teutschenthal is known to be a challenging track Axle deep ruts from post-to-post, rough and rutted inclines and descents that test the skills of the world's best are littered across the valley. I have experienced the track like this before but, luckily for all of us testing the 2020 YZ450F, it was a lot more forgiving. It provided a good range of soft, hard, rutted, smooth and rough sections that made it perfect to get an all-round feeling for the bike.
The first thing that came to mind when I sat on the YZ450F was how slim it felt. The bars were a little tall for my liking but as soon as I got on track I didn't notice the handlebars being overly tall and they made standing up feel quite comfortable. Along with the redesigned top clamp and handlebar mounts they gave a nice amount of flex and deadened impacts extremely well, because of this I didn't get the slightest trace of arm pump all day.
Whilst riding the cockpit felt a happy medium, I didn't feel as if there were any quirks to it and I felt comfortable quickly. I especially liked how easy it was to move around on this bike and the contact areas for your legs and knees were in the perfect position whilst standing. This gave me great confidence in knowing what the bike was doing at all times.
For a 450 the bike felt quite nimble whilst turning. I felt as if the front end would go where I directed it. The importance of the mass centralisation becomes clear and is a big factor in the bikes handling… It's even more evident when the bike is in the air. Considering the reciprocating mass and inertia that a 450 engine produces, I could hardly feel the effects of these forces whilst moving the bike around airborne.
Something that felt strange for me was the foot-peg position. With the aluminium frame, they bolt foot-peg mounts to the frame instead of them being welded to the actual frame. I found on occasion I would be standing more on the foot peg mount than the actual foot peg in order to keep my ankles tight to the bike. Under hard braking the larger pistons of the front brake really became noticeable. The lever had a really positive engagement and great feel that inspired me with confidence to squeeze harder.
The engine braking was not massively noticeable, which I think helped the balance of the chassis on the transition from power to brakes. The rear brake stabilised the bike nicely as well, and I didn't feel any signs of fade or overheating as I tend to be an abuser of it. If I could change one thing it would be to lengthen the rear-brake pedal ten millimetres, because it felt a little too close to the foot peg for my preference.
Another thing that helped the bike under braking was the front forks. They held nicely in the top of the stroke and contributed to balancing out the chassis. They took the impact of the bigger jumps extremely well and I had no bone-jarring impacts even when I decided to go a bit long off the many wall jumps. On the rougher corner entries, they felt a little disconnected from the ground as the front wheel glanced across several bumps in series.
It was a simple fix for me. Speeding up the rebound helped the front wheel keep up with the terrain. Also, with changing the fork height from ten millimetres to twelve millimetres I felt the bike was more predictable at turn in. In stock form I think these forks are the leader by a long way and with little changes for personal preference they can rival some very expensive equipment.
Moving to the rear of the bike, the shock felt a little unsettled for me and danced about over some of the squarer-edged bumps at high speed. I am not the heaviest of people so there's little chance of something feeling perfect for me in stock form. I opened up the high-speed compression half a turn to try and get it to absorb the square edges. This tamed the rear-end of the bike down. On the big stuff it soaked up the landings well. One thing I really liked about the shock was its feeling at slower speed, as it tracked the ground incredibly well and complimented the engine characteristics.
I was very impressed not only with the power of the engine but also its usability. The amount of torque meant that I didn't have to touch the clutch lever at all, even in the tightest of sections. The low-down grunt really allowed the bike to track on the exit of the slicker turns. I tried to get the bike to spin by being aggressive with the throttle but no big shakes and it would still find traction. I could let the engine run through the power curve and really take advantage of how linear it felt in the tighter sections.
The even range of power minimised gear changes too, which allowed me to focus more on my line choice and technique. On the faster sections, for example the pit lane straight, the YZ450F started to stretch its legs. On the transition from the mid-range to top end there was a massive surge of power, which left me with a childish grin on my face. Strong would be my description. However, at no point did the bike start to feel like wild or untamed.
Along with the strong engine package the YZ450F comes with a map switch and this was my favourite feature. I had two different maps loaded to the bike and I was able to switch them whilst riding. Being able to change the characteristics of the power delivery as track conditions change, or even as you start to get tired, is a game changer in my opinion. For example, in my one session it started raining and conditions got a little slippery. I switched from my preferred map, which was aggressive, to the smooth map, and the bike instantly became more manageable. Maps can be changed and created using the power-tuner app
Overall, I think the bike in stock form is very usable considering the power you have at hand. The predictable and stable handling from stock is impressive. Centralised mass is one of Yamaha's main priorities and its noticeable, as I felt comfortable with the chassis and its handling traits fairly quickly. The new front-brake design is a great improvement for me and one of the things I liked most about this bike. For a bike with so much technology, it is very user-friendly and with a few changes for personal preference I'm certain every rider would find a set-up they will feel very comfortable with.
|GYTR kit YZ450F|
Sat gleaming in the German sunshine was another YZ450F, this one fully kitted out with parts from GYTR. This included a ported head, camshafts, high-compression piston, Akrapovic titanium exhaust, billet-clutch assembly, billet clutch and ignition cover, glide plate, radiator braces, brake and clutch levers, brake hoses and a high seat. It's a long list of parts so I shall just cover what I thought made a difference.
The biggest difference I found between the stock and the GYTR bike was the extra torque from the bottom-end. I could make the bike pull a higher gear. The traction was immense and that made it deceivingly faster, because of how smooth it felt. Handling benefitted as well because it was revving less and this made the chassis relax, plus it helped the shock work properly and under less load.
Something that struck me as a bit unnecessary at first was the high sear. However, when I jumped on the bike it was instantly noticeable. It made the handlebar height more comfortable for me and also made the transition from standing to sitting much easier, meaning I could feel much more fluid in my movement over the more demanding sections of the circuit. It's no doubt that the GYTR parts make this bike feel more refined and for the serious racer it is a definite advantage over stock.
The ergonomics of the YZ250F feel no different to the 450, which I think is a great thing. On the track is where I could feel the difference in handling. I felt as though I could turn it on a dime with pinpoint accuracy. Even when I started to push the limits the bike's ability to turn was incredible… Confidence-inspiring is the best way to describe it.
To compliment the fast-turning characteristic of this bike, the engine had to be kept in the sweet spot of the revs. The mid-range is where I felt the meat of the power was placed on this bike. The top-end power was strong as well but in general I think the engine was quite tame, which in a sense is a good thing. I felt the bike gave me the confidence to really push the limits. Something that bugged me a couple of times was my left boot getting caught in the exhaust heat shield. Most of the time it just got snagged and was no major problem, but there was one time where my boot got wedged between the heat shield and the exhaust to the point where I had to slow down to unhook it.
|GYTR kit YZ250F|
The difference between the YZ250F in stock trim and with the GYTR parts was massive, it gave the bike more power in every area. The combination of the heavier flywheel and the cylinder head gave the bike serious bottom-end grunt, then a massive gain on the top-end and over-rev. I found the bike could be left longer in one gear, which for the serious racer is a split-second advantage. In some sections this allowed me to run a gear higher and helped me to keep a higher rolling speed throughout tighter corners. The bike with this spec has a nice balance between power and usability.
Words: Rob Holyoake | Lead Image: Yamaha Racing