The Art and Science of Building a Faster Electric Scooter—That Won’t Kill You
Electric scooters can be big fun if you know how to mod them safely and properly.
Electric scooters can be a convenient and low-stakes way to get around. Out of the box, most are fairly slow and tepid in performance. They're usually built to be safe and simple transport, not for hooning and tomfoolery. However, there’s nothing stopping you from building a performance electric scooter; often it takes just a few simple mods to go from mild to wild.
I’ve been building and modding electric scooters for over a decade, melting wheels and burning out motors along the way. Today, I’ll teach you the basic anatomy of the modern electric scooter, and how you can make them faster—much faster. Then you can shoot epic montages while blasting around at high speed. It's amazing fun.
But before we get to tinkering, heed this warning: Scooters come from the factory rated at certain speeds for safety reasons, and increasing a scooter's power also increases the risk of danger and injury, both while building and riding it, so be extremely mindful of that. You are working with batteries and electricity, after all. Always wear the appropriate safety gear, abide by local road laws, and be mindful of others' well-being.
Read that paragraph again. Internalize it. Got it? Good.
Basics of Electric Scooter Drivetrains
Before we get to pulling anything apart, it’s good to know what, exactly, drives an electric scooter.
At their heart, electric scooter drivetrains are very simple and consist of four major components. There’s a motor to drive the wheel and a battery that supplies power. There’s also an electronic speed controller (ESC) which varies the flow of power from the battery to the motor to control its speed, and some kind of throttle to send commands to the speed controller.
The speed controller is the thing that gives you throttle control over the scooter. The more power it allows to flow to the motor, the faster you go.
Some scooters get fancier about things, of course. Some will have a proprietary speed controller, which also drives a dashboard display, showing information about battery levels and speed. Others will have a special dual-speed controller capable of driving two motors, one front, and one rear. Most scooters make do with just driving one or the other, though. Cheap hub motor models may just drive the front wheel, while higher-end scooters tend towards driving the rear wheel or both.
The motors themselves can come in several forms, too. Old-school brushed DC motors aren’t commonly seen outside of toy-brand scooters like those from Razor. Brushless motors are far more popular these days for their greater efficiency, though they require fancier speed controllers to drive them. Hub motors, which fit entirely into the wheel itself, are a popular form of brushless motor. These are typically used in modern electric scooters, as they make it easy for manufacturers to build two-wheel-drive models.
As for batteries, the vast majority of scooters rely on lithium-ion cells similar to those used in modern electric cars. Other battery technologies exist, but most of them are heavier and store less energy, which makes for an incredibly slow, heavy scooter that can’t drive very far. If you've got a scooter that runs heavy lead-acid batteries, often a lithium-ion battery upgrade is a great mod to make.
Most scooters ship with pretty weedy power in stock form. Many countries limit electric scooters and other similar ride-on vehicles to a maximum power output of just 200 watts, which equates to a minuscule 0.26 horsepower. This is normally good for 15 mph at a maximum. Scooters for kids often have even less power.
You can build or modify a scooter to have way more power than that pretty easily. However, just beware: It’s often illegal to ride more powerful scooters on public thoroughfares in many jurisdictions—for the safety of both riders and everyone else. Keep that in mind before you go crazy building some high-powered monster.
Going Faster With What You’ve Got
So, now that you understand the basic elements of a scooter, you want to know how to make yours faster.
The most straightforward method is to work with what you’ve got in order to eke out as much performance from the stock components as possible. There are a few ways to go about this, and it’s typically the cheapest way to get more performance.
A few points of caution, however: There’s also a lower ceiling for what you can achieve if you do choose this path. You also run the risk of blowing up what you have. It’s not dissimilar to the car world. Yes, you can chuck a dinner plate-sized turbo on your mum’s Chevy Sonic, but you’ll blow the head off well before you get to 1,000 hp at the front wheels.
Additionally, some scooters come with speed restrictions baked in from the factory. These can often be lifted or removed with a firmware upgrade. Though, flashing your scooter with a different firmware risks bricking the device, making the scooter not work at all anymore. (Also, speed gains from firmware flashes are typically pretty minor. Manufacturers don’t leave a whole lot of performance gains on the table from stock.)
Upping the Current
But, depending on your scooter, getting a little more pep can be as easy as messing with the in-built current limit. Without getting into the physics behind it all, more current means more power, so that limit on current is what's limiting your fun.
Typically, the ESC contains what’s called a “current shunt.” It’s a fat piece of wire of a known resistance, and all the current going to the motor travels through it. The ESC uses this to measure the amount of current going to the motor and will cut power to the motor over a given limit to protect it and the battery from damage.
If you’re a rebel, though, you don’t give a damn about no damage! You can trick the scooter by adding metal onto the current shunt, which reduces its resistance. This is typically done by soldering an additional wire in parallel with the current shunt, thus fattening it up. This reduces the resistance and messes with the calibration. It makes the ESC think less current is flowing so it doesn’t trigger a limit condition.
This mod can give you more acceleration and sometimes more top speed. Just note you risk setting your ESC, batteries, or motor on fire if they can’t handle it.
How do you know if your parts can handle it? Well, much like engine tuners working on a car, you try it and see. Eventually, you’ll push it so hard that it breaks, and you’ll get a better idea of just what those stock parts can do before popping.
Do it outside and away from people and things in case it all catches fire, and be careful when you’re riding, too. Brushed speed controllers that fail can short circuit, supplying full battery power to the motor and sending you hurtling down the road at maximum speed. Alternatively, brushless controllers can make a motor stop dead or jerk suddenly when they fail, hurling you into a bush, a car, or an unlucky pedestrian.
As I said above, it’s a dangerous business. Building a modified scooter comes with risks, so you need to be careful. Wear protective gear and only ride where it’s safe. Plus, if you’re new to tinkering with electricity, do your research and get advice from someone that knows what’s safe.
The ‘Overvolt’ Mod
Going further, you can do an “overvolt” mod. Running more voltage through a motor gives more top speed and tends to boost acceleration across the board, too. This is typically achieved by replacing the scooter’s battery with one of a higher voltage. Or, in the quickest, dirtiest version, simply running a second battery in series with the first to double the voltage.
The gains from overvolting aren’t linear, but they can be darn close. You can easily boost your scooter’s top speed by 50 percent or more with this hack, but it comes at a price. The components in your scooter’s ESC are only rated to deal with so much voltage, and can easily fail when overvolted. The more you increase the voltage over stock, the more likely this can happen, and the quicker it’s likely to occur. The motor itself can also fail thanks to the excess heat melting insulation off the windings inside.
Either way, overvoltage failures typically lead to smoke and/or flames. You also risk the motor accelerating unexpectedly or suddenly stopping while you’re on the scooter, causing potential injuries. In fact, many scooters have fault protection in their ESCs that will shut them down if an overvoltage condition is detected. Canny tinkerers can work around these, but doing so can be tricky, and typically the parts aren’t rated to operate beyond such limits anyway.
That doesn’t mean you have to stop your hunt for more performance, though. Indeed, you’re just beginning!
Total Drivetrain Swaps
If you want to go really fast in an old Miata, you’re often better off dumping the stock economy-car engine for something with real performance. It’s the same with electric scooters. If you want big performance, don’t bother trying to mod the gear you already have. Rip out the existing ESC and batteries and replace them with more powerful gear. You’ll probably want to replace the motor, too—a new high-power battery and ESC will likely deliver so much power that your motor will simply melt into an anchor in a matter of minutes. That smells really bad (ask me how I know), so chuck it out as well.
Let’s say you’ve got a scooter with a 250-watt motor running off a 36-volt battery. You can rip all that out and buy yourself a higher-voltage battery, a higher-power motor, and an ESC to suit. They’re readily available on sites like eBay or Aliexpress. Typically, a roadgoing scooter would be plenty thrilling with a 48-volt battery and a 500- to 1,500-watt motor. However, 60-volt and 84-volt builds with motors in the 5,000-plus-watt range aren’t uncommon, particularly in larger off-road scooters with more space for batteries.
The challenge then is to fit all these new components in or on your scooter. Thankfully, wheels with higher-power hub motors are readily available, so the hardest part is often finding somewhere to stash a bigger, more powerful battery. Generally, an upgraded speed controller is small enough to lash onto the frame somewhere if you can’t install it internally. You’ll probably find you need a new throttle, too, to interface with your replacement ESC.
However, if you’re working with a scooter with a chain drive or belt drive, you might have to get more creative. This often involves building your own mounts to fit a larger, more powerful motor. Chain drives offer some flexibility in gearing that can be useful, too. You can gear the scooter down for better hillclimbing performance, or go the other way to get a higher top speed.
A total drivetrain swap is a great way to build a faster scooter. If you select a motor, ESC, and batteries that are all suited to each other, your risk of smoke, fire, and disaster is far lower. Of course, cheap components can still break, but you’re less likely to face issues if you’re properly speccing your components to work together.
Don't Be Me: Overpowered Isn’t Always Good
Faster is always better, right? Well, not always. There are still a few issues you can run into when trying to build a faster e-scooter.
You may find that your chosen scooter simply doesn’t like going faster. It may get nasty wobbles beyond a certain speed. You might find that going 30 mph on a scooter with no suspension is simply too terrifying on the bumpy roads in your area. The simple brakes fitted as stock may not be able to keep up with repeated stops from higher speeds, either, and could quickly degrade or fall apart entirely.
Don’t be me, that’s the trick here. The point of this article is for you to learn from the benefit of my experience, saving yourself from too many smoky expensive failures.
My first build was overpowered in the extreme. It was an unpowered Razer kick scooter, and I bolted what was ostensibly a 250-watt motor on the back. Overvolted, it was somewhere closer to 350. It had tiny four-inch rubber wheels, no ground clearance, and I’d added a good 20 pounds of weight in steel to fit the new drivetrain on the back.
After weeks of wrenching on that thing, I had a great ride that would hit 23 mph. Only on a dead flat surface, though, because even a pebble could send you flying with those tiny solid wheels. Oh, and those same wheels literally melted one day as I rode it 'round a roundabout. The plastic hubs simply weren’t designed to put that much power to the ground.
I dodged a few injuries when my other hacked-up scooters had sudden failures. My homebrewed speed controller would often fail, and when it did, it went full throttle. I’d be tooling along slowly on the footpath, only to have the scooter suddenly fly out from under me. Once, I managed to catch it and power-lifted it to the point I could yank out a battery lead to turn it off.
Alternatively, if I did manage to hang on, I’d quickly be going so fast that bailing out risked severe ankle injury or worse. These incidents eventually inspired me to implement a safety measure. I tied a pull cord around a 100-amp blade fuse and affixed the other end to my wrist. If I had a sudden runaway acceleration, I could yank my wrist and cut the power. It's the same concept as those safety clips you see on treadmills.
You might run into issues with the authorities, too. In many cities and countries, electric scooters are strictly limited to certain power levels—as previously mentioned, often below 200 watts. There are also restrictions on where you can ride them and at top speeds as well. Police may not readily be able to determine the power output of your scooter, but they won’t hesitate to act if you’re tearing up a local park and bowling over kids on their tricycles.
Faster builds aren’t suitable for the sidewalk, and drivers aren’t accustomed to looking out for scooter riders. Consider your own visibility, and choose where you ride very carefully. If you’ve built something truly fast, think about keeping it to private property for your own safe enjoyment. Also, the faster you go, the more likely you are to get road rash from a crash on the pavement, or a serious head injury from a collision. Helmets and protective gear are a must and become even more important at higher speeds. I never wore them in my early days, and to be honest, I was stupid for not doing so.
Overall, if you’ve built yourself a weapon of a scooter capable of breaking the speed limit on residential streets, you’re probably having a great time. However, you’re also probably breaking several local laws and putting yourself at risk. The lesson is to check your work carefully and be ready for the unexpected. Batteries can catch fire, speed controllers can fail, and throttles can stick. You need to be prepared for all these eventualities to protect yourself and others.
Fundamentally, building fast scooters is a great pastime. You can tweak your build for more speed and performance but at a much lower cost of entry compared to working on cars. Plus, it’s generally a lot less mess and grease, and you don’t require a whole garage to get started.
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