Everyone who owns a dirt bike wants to know how fast it goes – including you (and me). Especially people owning motocross race bikes. In this post, we’ll look at the top speed YZ450F.
I own a 2021 YZ450F and the bike is a rocketship, but just how fast is it? Here’s my 2021 YZ450F:
YZ450F Top Speed
Yamaha, known today for its motorcycles and musical instruments, released its first dirt bike in the mid-1950s.
It hasn’t always been this way, but today, many people are starting to think of Yamaha as having the fastest machines.
At least in the motocross racing world and with Yamaha’s big bikes, like the YZ250F and YZ450F.
Star Racing Yamaha’s team is growing in size fast, and their results are quite good too, with Eli Tomac winning about every major race and championship there was in 2022.
What does this mean for the YZ450F top speed?
The YZ450F top speed is about 75-85 mph.
This is about the same as the KTM SXF 450 top speed (the KTM SXF 450 might be slightly faster, but they’re very close). It’s also about the same as the CRF450R top speed (the YZ450F might have a slight edge in speed, but it’s close).
Why did I pick these two bikes to compare the YZ450F?
The KTM SXF 450 and CRF450R were both chosen to compare the YZ450F to because they are the most common 450 motocross bikes people ride and race. There are other brands, like GasGas, Husquvarna, and Suzuki, but the KTM and CRF are the most common 450s.
What changes the top speed YZ450F?
It can be tough at times to calculate the true top speed of a dirt bike because there are quite a few different items that can impact it. Let’s take a look at them.
This might be obvious to some, but engine work and aftermarket parts are going to impact the YZ450F top speed. Arguably, most of anything.
If your YZ450F has engine work and a pipe, that’s not really comparable to the top speed of a stock YZ450F.
Take Eli Tomac’s factory Star Racing Yamaha YZ450F for example. That can’t be compared to a stock YZ450F off the dealership floor.
The top speed of a YZ450F that hasn’t had any work done to it will be significantly lower than the top speed of a YZ450F that has undergone a ton of mods.
The more work you do to the bike, the greater the difference in speeds will be.
There are other factors at play here too – such as gearing, riding conditions, and more.
The second most important factor in determining the YZ450F top speed is its gearing. Gearing refers to the size (and ratio) of the front and rear sprockets.
For reference, the stock gearing for this bike is a 13-tooth front sprocket and a 49-tooth rear sprocket (depending on the year of your bike).
Riders normally pick different gearing depending on the situation they’re riding. If the rider is racing supercross, they would typically want more acceleration (referred to as more bottom end). To achieve this, they’d use either a smaller front sprocket or a larger rear one. This is known as having a low gear ratio.
You may not have to rely on this as much for bottom end with a YZ450F because 450s have so much torque and bottom end, but it is certainly something that’s adjusted when needed.
If the rider is racing motocross, they may want more top speed (known as top end). To do this, the rider would use a larger front sprocket or a smaller rear sprocket; in other words, they would be changing to a higher gear ratio.
Riding in the woods can require an entirely different gearing combination than that of supercross or motocross.
This might not sound like much to some people, but it has a large impact on the top speed of YZ450F (or any dirt bike, for that matter). Depending on the gear changes made, it can increase or decrease the YZ450F top speed by more than 5-10 mph.
A YZ450F with an 8-tooth front sprocket will have a different top speed than one with the stock 14-tooth front sprocket (I made the difference wide to make a point — no one is running an 8-tooth front sprocket on their YZ450F….).
Additionally, a change to the front sprocket has a great effect on the YZ450F top speed and bottom end than changing the rear sprocket. Going up or down one tooth on the front sprocket is not equal to one tooth on the rear sprocket.
Rather, changing the front sprocket by one tooth is equivalent to 3-4 teeth in the rear.
The top speed of a YZ450F is going to be slower if the rider weighs more because it takes more work from the bike, while the bike and engine maintain the same ability/capacity. The heavier the rider, generally the lower the YZ450F top speed is going to be.
This isn’t going to be as impactful with a bike like a 450 given how much power they have. The rider’s weight would impact a smaller displacement bike more, like a Yamaha YZ125 as an example.
In addition, an experienced rider can make the YZ450F go faster than a beginner who is just learning. A rider who knows how to quickly and smoothly shift gears can hit a higher top speed than someone who is just learning how to use a clutch.
Consider Eli Tomac riding the YZ450F versus someone who is buying a 450 for their first dirt bike. Who do you think is going to be able to make the bike go faster?
Sure, the bike’s capability and the top speed the 450F could technically go is the same — that doesn’t change with the rider’s ability — but that rider’s ability impacts whether the rider can reach that top speed or not.
The YZ450F top speed can also be impacted by riding conditions, including both location and surface.
For example, a dirt bike’s power output is generally higher closer to sea level than at high altitudes. So if you’re planning to ride your YZ450F in the mountains, it will likely have a lower top speed than if you were riding at sea level.
Or, even if you’re not in the mountains necessarily, but you’re just riding in Colorado, you’re much higher above sea level than the coasts of the US. That will cause your YZ450F top speed to be lower.
Smaller-size bikes (bikes with small cc engines) are more impacted by elevation changes than larger bikes, too. For example, a YZ85 is going to be more impacted than a YZ450F.
Are you riding in the woods, on a motocross track, or on a paved road (maybe a YZ450 supermoto setup)?
If it’s in the woods, your top speed might be limited. If you’re racing motocross, you can only go so fast while remaining safe and within bounds (and, don’t forget, sometimes slow is fast when racing).
Apart from the elevation and location, another factor that affects the YZ450F top speed is the surface on which it is being ridden. The top speed YZ450F ridden on flat pavement will be different than if it were driven on a tight, sandy motocross track; even the type of tires can make a difference.
A Few Other Factors that Can Impact the YZ450F top speed
Your YZ450F top speed can also be impacted by a few more things, including the condition of your bike, the weather, and how you’re recording the data.
A bike that is regularly maintained will run faster and more efficiently than one that isn’t. For example, a YZ450F that has had consistent maintenance done to it will be able to reach a higher top speed than one not taken care of properly.
The weather and temperature can both affect your YZ450F top speed. If it rains, the pavement will be wet, or the track may be muddy, and your top speed will probably be lower than normal,.
If you want to get an accurate reading of the top speed YZ450F, use an onboard GPS device rather than relying on someone pointing a speed gauge at you as you zoom past. This doesn’t mean the bike will actually go any faster or slower, it just changes what you end up seeing on paper.
Waving the White Flag on the top speed YZ450F
As we pass by the white flag of this article and enter into the last lap, I want to summarize what I’ve covered so far.
Ultimately, most people want to know their bike’s rough top speed. Yes, mods and other items impact a YZ450F top speed potential, but at the end of the day, people just want to have an idea of how fast their bike is.
With that in mind, a YZ450F top speed is about 75-85 mph.
Frequently Asked Questions About the YZ450F Top Speed
Yes, the YZ450F is a very powerful dirt bike.
Yes, a YZ450F is a motocross race bike.
Yes, a 450 is too much power for a beginner. This does not mean that a beginner could not ride a 450, of course they could, but it’s likely not the right choice. They’re better off starting with a 125 or a 250, if they’re an adult, then moving up to a 450 once they’re ready.
A 450 dirt bike is significantly faster than a 250.
No, a 450 dirt bike isn’t good for beginners. With improved 4-stroke technology today, 450 dirt bikes are incredibly fast and powerful. Beginners, if they’re an adult, are better off starting with a 125 or 250, then working their way up to a 450.
The F in YZ450F means four stroke (4-stroke).