Today, a considerable range of 125cc bikes is on the market, from scooters to sports bikes. 125cc motorcycles are small, lightweight types of motorcycles that typically have a single-cylinder. They have a low power output and are more maneuverable.
So, how fast does a 125cc motorbike go? A 125cc bike can hit top speeds of 105 miles per hour. However, most perform in the 55mph – 80mph range.
Table of contents
What is the top speed of a 125cc motorcycle?
The average top speed of a 125cc bike ranges from 55 to 80 miles per hour (mph). But some bikes can cross 100 mph or more.
But only some riders will run at these maximum speeds. This is because many are often beginners or young people yet to master the riding skill.
Pushing your bike’s engine to its maximum speed too often can result in quicker wear and tear if not serviced more frequently.
125cc bikes are lightweights in the world of bikes, and they become relatively unstable at top speeds. This is unlike superbikes that can cross 120 mph with ease and can exceed 180mph if needed.
What does 125cc mean?
The cc stands for cubic centimeters. It’s a measurement of the size of the engine chamber. It helps indirectly describe how much power a bike has—the lower the cc number, the lower the power the engine generates effectively.
Ten of the fastest 125cc motorcycles
| Model & manufacturer | Max speed (mph) | Engine capacity & cylinders | 2 or 4 stroke |
| Aprilia RS 125 | 107 | 124.8cc, liquid-cooled, single-cylinder | 2-stroke |
| Cagiva Mito 125 | 105 | 125.6cc, liquid-cooled, single-cylinder | 2-stroke |
| Honda NSR 125 | 105 | 124.8cc, liquid-cooled, single-cylinder | 2-stroke |
| Derbi GPR 125 | 102 | 125cc, liquid-cooled, single-cylinder | 2-stroke |
| Yamaha TZR 125 | 94/95 | 124cc, liquid-cooled, single-cylinder | 2-stroke |
| Yamaha MT 125 | 85 | 124cc, liquid-cooled, single-cylinder | 4-stroke |
| Benelli TNT 125 | 78 | 125cc, air-cooled, single-cylinder | 4-stroke |
| KTM Duke 125 | 75 | 124.7cc, liquid-cooled, single-cylinder | 4-stroke |
| Honda CB125R | 75 | 125cc, liquid-cooled, single-cylinder | 4-stroke |
| Kawasaki Ninja Z125 | 73 | 125cc, liquid-cooled, single-cylinder | 4-stroke |
Point to be noted regarding the Aprilia RS 125 and Derbi GPR 125:
Both models’ 2-stroke engines have been replaced by 4-stroke engines (in 2012 for Aprilia RS125 and since 2010 for Derbi GRP 125). But the 2-stroke bikes remain immensely popular among motorcyclists.
What affects the top speed of a 125cc bike?
The average highest speed of 125cc motorcycles depends on the bike’s engine size, sprocket gearing, and many more factors. Let’s have a more in-depth look at all the different aspects.
Two-stroke vs four-stroke engines on 125 cc motorcycles
The most significant difference between the two engines is the number of strokes or cycles the piston requires to produce power from the air and fuel mixture.
Two-stroke engine
In a 2-stroke engine, compression and combustion are the primary functions. It’s fast and hard, which makes it great for off-track riding. If speed is more important to you, this is a good option because you can get up to 60 mph with it. Some can even manage to reach 100mph.
But this option is not commonly available on newer bikes today. While it is cheaper to manufacture, the engine causes a lot more pollution. The engine’s working produces thick, white smoke and unburnt oil and fuel mixture. This is very harmful to the environment.
Manufacturers were not able to control the pollution levels that two-stroke engines emit. And they couldn’t comply with the new emission standards that were set by most countries. So, many have stopped manufacturing them.
Four-stroke engine
A 4-stroke engine, on the other hand, is considered to be slower than a 2-stroke. But one important thing to note is that four-stroke engines can also vary significantly in terms of speed.
Some 4-strokes will allow you to reach an average max speed of 35mph, while some 4-strokes will allow you to go as high as 80 mph. How do you know then which one of these 4-strokes will perform better?
Well, in most cases, you can judge the 4-stroke by its price. Usually, the most expensive ones are the ones that go faster. But then again, this is only sometimes true. So, you must check the specs sheet on the bike manufacturer’s website.
You can also check online on Google or social media to see what people who already own the bike have to say. Social proof might be a great way of going about it.
I ride with bikers of varying ages, experience, and knowledge. So, I can invariably find someone who answers most bike-related questions.
The point is to check with your riding crew. 🙂
Modifying your 125 cc motorcycle for more speed
What if you want to increase your bike’s average speed without sacrificing its low-end torque? You can achieve that by sprocket replacement or “sprocketing.”
Altering the gear ratio of a motorcycle by modifying the sprocket is known as sprocketing.
A bigger rear sprocket/ smaller front sprocket will give you an increase in acceleration but decrease your top speed. A smaller rear sprocket/bigger front sprocket will reduce your acceleration but increase the maximum speed.
To get the bike’s top speed, you could, for example, go from the factory 14-tooth drive sprocket to a 15-tooth one. A 32-tooth gearing on the back of your bike, on the other hand, will add speed but reduce the low-end torque acceleration of your bike.
So, many experienced riders use this technique to add more power or top speed to their existing bike. And this is also possible without spending much money.
Total weight of the motorcycle
Similar to cars or other vehicles, the load of a 125cc bike also significantly impacts its top speed. Depending on the model, the maximum load can range from 200 to 250 pounds.
The load depends not only on the weight of the rider but also on the cargo and the components of the dirt bike. Modifications that add weight can also make it heavier, slowing down the overall speed limit.
The rider’s experience and environmental factors
The experience of the rider can also affect the top speed of a 125cc bike.
You bet it does.
A motorcycle, most of the time, only goes as fast as the biker can take it!
Sidenote: My Kawasaki ZX-10R can push beyond 180mph. But it took me some getting used to before I could go that fast.
But an experienced rider will be able to reach higher top speeds more safely. So, your experience can affect the overall performance of the bike. You can even test this in time trials.
The environment you are driving in can also affect the bike’s average speed. The muddier the terrain, the slower it will be. But on the other hand, it can be faster in downhill road conditions.
Windy weather can also increase the drag, making it more difficult for a bike to reach its top speed.
How many seconds does a 125cc bike take to reach max speed?
Depending on the engine type and whether it’s a four-stroke or a two-stroke, the time it takes to reach top speed can vary. But it usually takes 4 seconds with 4-stroke manual transmission bikes and about 7 seconds with bikes that have automatic transmission.
Tips to make your 125cc bike perform faster and better
You, of course, cannot change the essential qualities of your 125cc bike. But here are some tips to help it perform smoother and, possibly, reach higher speeds.
Maintaining physical fitness
Your bike may have some special functions, but the rider’s physical condition is also essential to make it perform at its best.
So, train your body and be ready for the demands of the ride. The better your physical condition, the easier it is to reach the bike’s top speed.
Example on point: Marc Marques struggled terribly because of this shoulder injury in MotoGP. As of this writing, he is making a comeback!
Modify the exhaust
No matter how much work you put into the ride, your bike will not be at its fastest if it has stock components. Performance upgrades are essential, and the most important is the bike’s exhaust.
The muffler is a crucial component of the exhaust system. Add a pipe in a two-stroke engine or a slip-on in a four-stroke engine for minimal but crucial speed improvements. This process will take only about 15 minutes, and even a new rider can do it.
On crotch rockets, however, you can even swap out the entire exhaust system.
Adjust the suspension
Consider buying an upgraded suspension for your 125cc bike. It can be expensive, but it is worth the cost. Why? An enhanced suspension will improve your control over the motorbike, even in challenging terrains. This will let you handle the bike better, positively affecting its speed.
It also makes the bike feel more balanced and helps in shock absorption.
Essential safety tips to keep in mind
The rush of adrenaline while riding your bike at high speed is excellent. But it is also equally important not to neglect safety. This is especially important for 125cc bike riders, who are often beginners and young. So, here are the most important things to keep in mind.
- Always follow the bike’s speed limit and traffic rules. This is crucial for all riders, and even more so if you are riding on public roads. Compulsory basic training is also essential.
- Familiarize yourself with the area you are riding in before you begin your ride. Learn about the surface you will be riding in, and check the map for twists and turns. Also, do keep an eye on weather conditions that can impact the area on longer journeys.
- Always inspect your bike correctly before each ride. This can help you catch any potential problems and fix them. You don’t want your bike to stop working and be stranded somewhere where you can’t find help.
- Wear the proper protective gear for your ride, which can keep you safe but also maneuver properly. Invest in good-quality helmets, knee pads, and other accessories that will be useful for you.
- Last but not least, be aware of the level of your riding skills. This way, you won’t push yourself or your bike beyond what you are capable of.
Conclusion
A 125cc bike may not be the fastest motorcycle around, but the excitement you feel will not be any less. Since the 125cc bikes are nimble and responsive, they are super fun to ride on!
Be careful when you push the limits, though, because the line between extreme fun and sanity is thin!
