Pit bikes are a relatively new phenomenon in the world of two wheels are come in a variety of displacements including 70cc, 110cc and 125cc pit bikes. These minibikes fit in a very peculiar place within the traditional motorcycle line-up.
Originally, they were created to help racers get between their trailers and the pit quickly without breaking the track rules, but now they are public knowledge and it seems that everyone loves the idea of a pit bike.
Their uses have expanded too, and while pit bikes were originally for adults, they can also be the ideal starter bike for kids looking to get into motocross or dirt riding.
When it comes to choosing a pit bike that’s right for you or your kid, there are a lot of factors to take into account, and engine displacement is one of the most commonly debated questions.
Today, we are going to help you choose what we consider the best 125cc pit bikes as well as a general guide as to choosing the right bike for you.
The Pit Bike CC Displacement War
The size of a pit bike engines is growing rapidly and beginning to push the boundaries of what these little single cylinder motors can produce in this traditional forward facing layout.
125cc pit bikes are probably the most common at this time, however their larger 140cc cousins are increasingly popular and set to take over in the near future. However, bigger is not always better.
The original pit bikes were more commonly found in 50cc or 70cc sizes and this was seen as ample for a bit of fun, but as these little motorcycles became more popular and even began to be raced against each other the displacement war began in search of more power and torque.
As pit bikes all have the same engine layout and a consistent bolt pattern for their engine mounts, they are great fun to tinker with and tune. Even full engine swaps are easy with these bikes and you can get a 125cc pit bike engine kit for merely a few hundred pounds these days.
However, there’s an inherent limitation to these engines in their layout and size, and if you bore or stroke your pit bike engine so far you will find considerable diminishing returns combined with a new tendency for unreliability. In our experience, the sweet spot is probably 125cc pit bikes which are known to be particularly durable.
How Fast is a 125cc Pit Bike?
When it comes to speed, 125cc pit bikes have a lot to offer. These little engines offer remarkable power outputs for their physical size. But the truth is, whether it is enough for you depends what you want out of a pit bike and what you are trying to use it for.
125cc pit bikes have a solid top speed of 40-50mph depending on a lot of other factors and tend to push around 9 horsepower. It’s nice and easy to compare pit bikes by their top speed but you always need to bear in mind the other factors which can have a considerable effect on this metric.
One of these would be their aerodynamic drag coefficient. Pit bikes are generally based on a dirt bike or motocross style bike which often come with considerably more powerful engines and are raced on tight tracks where their top speed is not a big consideration or at all a factor for gaining race wins.
Because of this styling, pit bikes top speed can be greatly affected, although on a minibike, 50mph should be enough for anyone!
You can get 125cc pit bikes registered and road legal if you want to ride them on the road, but on the open road they can only just about keep up with the flow of traffic and need to be worked very hard to do so, so its not always recommended, despite a wealth of aftermarket support such as different sized front and rear sprockets that will buy you a bit more top cruising speed.
If you’re willing to push it to the extreme and are not scared of doing extensive modifications or looking silly, the top speed recorded from a 125cc pit bike is over 100mph which is as impressive as it is dangerous.
If you’re racing your 125cc pit bike on the traditional tight and twisty dirt tracks then you will be much more interested in how fast it can accelerate. It will be set up pretty well as it comes from the manufacturer with short gearing to enable you to keep your pit bike engine in its powerband.
If you’re looking for a 0-60 time for one of these 125cc pit bikes, you’re out of luck because they won’t reach 60mph in stock form unless you’re going down a very steep hill with a very strong tail wind.
However, they tend to reach their top speeds within around 12 seconds or so. This sounds pretty slow, and when compared to a traditional full-size dirt bike like a 2-stroke 125cc Yamaha YZ125, or even your average hatchback car, it really is!
However, while it will never stack up to a proper dirt bike off-road, or a hatchback on the road, pit bikes have plenty of low down grunt and in the speed range you will be riding them within if you’re using them for what they were intended for.
You will find there to be plenty of acceleration from 125cc pit bikes between 5 and 25mph and if you’re keen with the clutch and throttle you may even find the front wheel lifting in first and second gears if you’ve got enough traction on the surface you’re on.
As these little bikes are so light that they really don’t need much power to feel like they take off.
Torque is one of the more complicated metrics to understand when it comes to engine power. It’s easier to think of torque as the strength of the engine in its ability to turn the wheel, not to be confused with power which would be torque multiplied by engine RPM.
Again, there is no point in comparing 125cc pit bikes torque figures to that of a car’s or even a traditional full sized bike. But the truth is, a 125cc pit bike can offer good torque for its size and weight.
Engine displacement has a big effect on torque because with a larger CC capacity you are effectively increasing the size of the fuel and air mixture to produce a larger combustion event within the cylinder forcing the piston through its revolution.
The additional torque is one of the key reasons you’d select a larger engine 125cc pit bike over a smaller 50 or 70cc option. Torque really comes in to play when you’re off-road trail riding and find yourself trying to climb up a steeper ascent. With less torque you could find your engine getting bogged down to the point of stalling part way up.
With 125cc pit bikes, this is generally not a problem and they have plenty of grunt to send you up a hill providing the back wheel has enough traction in the dirt to do so.
What to look out for when buying a 125cc pit bike
Selecting your ideal pit bike isn’t as easy as just knowing what engine size you’re after. There’s also a ton of other specs you will want to be mindful of too. Of course, this is all dependent on what key factors hold the most value for you.
- Manufacturer’s Warranty
- Proximity of Approved Mechanics
- Parts Availability
- Aftermarket Support
Pit bikes can come directly to your home in a big box through the post in this day and age, and this can quite often be the most convenient way to acquire one. If you’re taking advantage of this type of distance purchasing you’ll want to be confident in the manufacturer’s warranty of taking care of you should any unexpected issues arise.
You can mitigate your concerns about this by looking up motorcycle mechanics in your local area to discover whether they can work on your pit bike if needs be. As these are uncommon bikes, many mechanics don’t have easy access to the correct parts for them so it’s always worth checking with them.
You can always circumvent this issue by visiting an approved pit bike dealer and receiving the more traditional purchase experience and you can maintain that lifeline for advice when it comes to maintaining and repairing your pit bike in the future too.
As many pit bikes are Chinese made, while their parts are cheap and plentiful, they can at times be a bit more difficult to source and a traditional parts shop won’t necessarily have these more unusual parts in stock for a quick turnaround. This is something to be aware of when maintaining your pit bike.
Aftermarket support is another big one. The wonder of pit bikes is their simplicity and the opportunity to crack the spanners out and do a bit of home wrenching. This can be greatly satisfying and for many types of pit bike there’s a lot of aftermarket tuning parts available and many uprated parts to upgrade your bike in the future and extend its service life.
Its always worth doing some research online to find out whether there are good sources of information and advice online for the type of 125cc pit bike you’re interested in purchasing.
125cc Pit Bike Brands
There are many different 125cc pit bikes available on the market as it is one of the more popular sizes. There are some limitations on stock availability in the UK but that doesn’t mean you can;t get your hands on some of the best quality bikes available. See our suggestions below for a quality pit bike.
1. M2R Racing KMXR125
M2R Racing pit bikes are some of the more popular available options in the UK and with good reason. They are generally considered one of the best put together pit bikes available on the market. With a smaller wheel size this 125cc pit bike is probably the perfect choice for kids or young teens to thrash around on.
With reinforced hubs and plenty of adjustability, these M2R pit bikes are a great starting point and you should find yourself able to hop on and ride with much fewer fiddly issues than you could expect from the bottom of the range cheaper pit bike options.
2. Stomp 120R
Stomp has become a big name in pit bikes, and their brand reputation is growing all the time. This is partly down to their continual refinement of the platform and at this stage they are on to something good.
While this is technically a 120cc pit bike rather than a 125cc, power output and various other factors put this pit bike squarely in the options list.
Stomp have clearly put additional effort into the fit and finish on their products and their bikes are carefully designed to look the part with aggressive yet functional styling.
Luckily, they come with a tried and tested Lifan 120cc engine which can be found in many bikes and has a reputation for being a stalwart unit that is extremely durable.
3. Demon X DCR2 125
Demon X is somewhat of a sister brand to Stomp and again have a big presence on the UK 125cc pit bike market with good reason. The Demon X DCR2 is a wonderfully designed bike again featuring that peach of a Lifan engine but paired with a Mikuni carb to give it a bit more kick.
The Demon X plastics and eye-catching graphics give absolutely no hint that this 125cc pit bike is of Chinese origin, and like the Stomp, these pit bikes are exceptionally well put together and ready to ride.
4. WPB Race 125
WPB are storming the UK pit bike market, while the parts are still largely sourced from Chinese suppliers, they are put together by a Welsh company with a great attention to detail. The WPB 125 is a great height for an adult rider with a bespoke frame geometry design featuring a taller headstock, raised seat height, and swing arm.
The best part about the WPB is their additional attention to detail when it comes to setting their engines up, for a 125cc pit bike engine they are kicking out around 12hp which is a figure up on the vast majority of the competition at this displacement. This is largely thanks to a couple of tick engine components such as a race camshaft which gives the valves additional lift.
There is a sea of options when it comes to 125cc pit bikes and hopefully, the above advice and suggestions on how to pick the right bike for you will help shed some light on a lot of the more common questions that get asked.
Do you have any other 125cc pit bikes that you think should have made the list of the best 125c pit bikes? If so, get in touch in the comments section below.