How to remove speed limiter from your electric bike

Most e-bikes sold in the U.S. ship with a speed limiter that caps pedal assist at 20 mph (Class 1 or 2) or 28 mph (Class 3). That limiter isn’t one hidden switch—it’s typically a combination of controller firmware, a speed sensor signal, and sometimes a physical loop wire in the wiring harness. Removing it means changing how the controller interprets wheel speed, and the method that works depends entirely on your bike’s specific controller and display.

Before you touch any wires, understand the trade-off: derestricting a Class 1 or Class 2 bike can make it illegal to ride on public roads, voids your warranty, and increases stress on components that weren’t designed for sustained higher speeds. This guide walks through the three main removal methods in order of invasiveness, what tools you’ll need, and how to verify the change actually worked.

What You Need Before You Start

Gather these items before opening any housing:

• Phillips and flathead screwdrivers — for controller housing and display brackets
• Pin extractor tool — for pulling limiter wire terminals without cutting (a small jeweler’s flathead works in a pinch)
• Zip ties — for securing any disconnected wires or emulator devices
• Multimeter — to verify you’ve disconnected the battery properly and to test continuity on suspect wires
• Phone or camera — to photograph the controller sticker and wiring layout before disconnecting anything

Critical first step: Disconnect the battery and wait at least 5 minutes before opening the controller housing. The controller’s capacitors can hold a dangerous charge for several minutes after power is removed. If you’re not comfortable working around live electrical components, stop here and take the bike to a shop.

You also need to identify your system. Open the display unit or controller housing (usually under the battery mount or inside the downtube) and look for:

• Controller brand and model number — printed on a sticker. Common brands include Bafang, Shengyi, KT (Kunteng), and Lishui.
• Display type — LCD displays like the King Meter 7900 or Bafang C965 have hidden menus; basic LED displays often don’t.
• Connector layout — count the pins on the speed sensor cable. A three-pin connector (red, black, signal) is standard. Some controllers have a separate “limit wire” that’s a single white or blue loop.

Take photos of everything. If you need to order a replacement controller or display later, you’ll need that model number.

Method 1: Change the Speed Limit Through the Display Menu

This is the least invasive method and works on many bikes with LCD displays. KT and Bafang displays commonly have a hidden settings menu that lets you adjust speed limit parameters, wheel diameter, and other controller settings.

Typical steps for a King Meter or KT-LCD display:

1. Turn the bike off.

2. Press and hold both the “UP” and “DOWN” buttons simultaneously, then turn the bike on.

3. Wait for the advanced settings menu (usually labeled “P” or “C” parameters) to appear.

4. Scroll to P1 or C5 (the speed limit setting). The default is often 25 km/h (15.5 mph) or 32 km/h (20 mph).

5. Change the value to the maximum allowed (often 40 or 50 km/h) or set it to “100” if the display uses a percentage.

6. Save and exit.

Also check the wheel diameter setting (often P2 or C4). If the display thinks your wheel is smaller than it actually is, it overestimates your speed and cuts power early. Setting the correct wheel size—27.5″ or 29″ for most modern e-bikes—can recover 1–2 mph of top speed even without touching the limit parameter.

Verification: After saving, ride on a flat, private road and watch the assist cutoff. If the motor now provides power past the previous cutoff speed, the change worked. If the bike still cuts out at the same speed, the limit is enforced at the controller firmware level, not the display level—you’ll need Method 2 or 3.

Failure mode: Some displays let you raise the speed limit value, but the controller firmware ignores it and still caps the motor. This is common on newer Bafang systems where the display and controller must be firmware-matched. If you change the setting, save, and see no difference, don’t keep experimenting with other parameters—you risk changing settings you don’t understand. Move to the hardware methods below.

Method 2: Cut or Disconnect the Speed Limiter Wire

Some controllers, particularly older Bafang and Shengyi units, have a dedicated speed limiter wire. It’s usually a single wire in the main harness—often white, blue, or yellow—that loops back into the connector. When the loop is intact, the controller limits speed. When you break the loop, the controller assumes no speed sensor is present and disables the limit.

How to identify it:

• Look for a wire that enters a connector pin and loops back into the adjacent pin on the same connector.
• Check the controller sticker for a wiring diagram. Many Bafang controllers label it “LS” (limit switch) or “SPD” (speed).
• If you see a two-pin connector with a single wire looping between the pins, that’s almost certainly the limiter.

Procedure:

1. Disconnect the battery and wait 5 minutes for the controller capacitors to discharge.

2. Locate the limiter loop in the harness.

3. Use a pin extractor tool or a small flathead screwdriver to release the terminal from the connector housing. Do not cut the wire if you can avoid it—pulling the pin lets you reverse the change later for warranty service or resale.

4. Tape the loose pin and wire back to the harness so it doesn’t short against anything.

5. Reconnect the battery and test.

Verification: Ride on a flat road and note the cutoff speed. If the motor now assists past the previous limit, the loop was the limiter. If you get an error code on the display—commonly E07 or E08 on Bafang systems—you’ve pulled the wrong wire. That’s the actual speed sensor signal, not the limiter. Reinsert the pin and try Method 1 or 3 instead.

Failure mode: On many modern controllers, disconnecting the speed sensor entirely triggers a fault code and the motor won’t run at all. If that happens, you’ve confirmed the controller needs a valid speed signal to operate. Reconnect the wire and move to Method 3.

Method 3: Install a Speed Limiter Removal Device (Emulator)

If your controller has no hidden menu and no limiter wire, a speed limiter emulator is the remaining option. This small device plugs inline with the speed sensor and modifies the pulse signal sent to the controller. The controller thinks you’re riding slower than you actually are, so it keeps providing power past the normal cutoff.

How it works: The speed sensor on your wheel sends a pulse signal to the controller—usually one pulse per magnet pass. The emulator intercepts that signal and either halves the pulse frequency or generates a modified signal that keeps the controller below its speed threshold. The motor keeps assisting at speeds well past the original limit.

Installation steps:

1. Disconnect the battery and wait 5 minutes.

2. Locate the speed sensor cable where it connects to the main harness (usually near the rear dropout or the controller).

3. Unplug the sensor from the harness.

4. Plug the emulator into the harness, then plug the sensor into the emulator.

5. Secure the emulator to the frame with a zip tie, keeping it away from the chain and moving parts.

6. Reconnect the battery and test.

What to look for: Choose a device rated for your controller’s voltage (36V, 48V, or 52V). Many emulators are universal, but some are brand-specific. Check the connector type—most use a standard 3-pin JST connector, but some manufacturers use proprietary plugs. If the connector doesn’t match, you’ll need an adapter or you’ll have to splice wires.

Verification: Ride on a flat, private road. If the motor now provides assist past the previous cutoff, the emulator is working. Important: The emulator makes your speedometer read low. If your display shows 20 mph, you’re likely going 24–25 mph. Use a GPS bike computer to confirm your actual speed—don’t rely on the display.

Failure mode: If the motor cuts out or stutters at high RPM, the emulator’s signal modification may be too aggressive for your controller. Some controllers detect an inconsistent speed signal and trigger a fault. If you get an error code, remove the emulator and reconnect the sensor directly. The bike should return to normal operation immediately.

What Changes After Removal: Speed, Range, and Heat

Removing the limiter doesn’t just raise your top speed—it changes how the entire system behaves. Here’s what to expect:

Speed gain depends on motor type. A geared hub motor (like a Bafang G310) will gain 3–5 mph past the limiter before it hits its mechanical RPM ceiling. A direct-drive hub motor (like a Crystalyte) can gain 8–12 mph because it’s not gear-limited. A mid-drive motor (like a Bafang BBS02) gains the most, since it drives through the bike’s gears—you can pedal to a higher cadence and the motor keeps assisting.

Range drops disproportionately. The motor’s power draw increases roughly with the cube of speed. Going from 20 mph to 25 mph doesn’t use 25% more battery—it uses roughly 50–60% more. A bike that gets 40 miles of range at 20 mph might only get 25 miles at 25 mph. If you commute a fixed distance, you may need to charge at work or carry a second battery.

Heat becomes a real risk. The controller and motor are designed to shed heat at a certain continuous power level. Pushing past the limiter means sustained higher current, which means more heat. On a hot day, a direct-drive hub motor can overheat and demagnetize its magnets—a permanent failure that requires a full motor replacement. If the motor housing feels hot to the touch (above about 140°F), back off and let it cool.

Braking distance grows. Your brakes don’t get an upgrade when you remove the limiter. At 28 mph instead of 20 mph, your stopping distance increases by roughly 50%—and that’s assuming the same brake pads. If you have mechanical disc brakes, consider upgrading to hydraulic before riding faster. This isn’t optional if you’re riding on public roads.

Legal and Safety Considerations: Know Your Class

The U.S. consumer e-bike classification system is straightforward:

• Class 1: Pedal assist only, max 20 mph
• Class 2: Throttle assist, max 20 mph
• Class 3: Pedal assist only, max 28 mph

Removing the limiter on a Class 1 or Class 2 bike makes it a “Class 3+” or unclassified vehicle. On public roads, that can mean:

• You’re riding a motor vehicle without registration. Some states classify any e-bike over 28 mph as a moped or motorcycle, requiring a license, insurance, and registration.
• You lose access to bike paths and trails. Many municipalities restrict e-bikes to Class 1 on multi-use paths. A derestricted bike is legally a motor vehicle, and riding it there can result in fines.
• Your insurance won’t cover you. If you’re in an accident and an investigation finds your bike exceeds its class rating, your homeowner’s or renter’s insurance may deny your claim.

If you’re riding on private property or a closed course, these concerns don’t apply. If you’re riding on public roads, keep the limiter intact or accept the legal risk.

FAQ

Will removing the speed limiter damage my motor?

Not immediately, but sustained operation above the motor’s rated RPM or power level increases heat and wear. Direct-drive motors are most at risk of overheating; geared hub motors risk gear wear. If you ride derestricted regularly, expect shorter motor and controller lifespan.

Can I reverse the change if I need warranty service?

Yes, if you use the display menu method or pull the limiter wire pin instead of cutting it. Emulators are also removable. If you cut wires or flash custom firmware, the change is visible to a technician and will void your warranty.

Why does my bike cut out at exactly 20 mph even after I changed the display setting?

The display setting only controls what the display shows. The actual speed limit is enforced by the controller firmware. If changing the display parameter doesn’t help, you need an emulator or a controller reflash.

Is there a legal way to get a faster e-bike?

Yes. Buy a Class 3 e-bike (28 mph pedal assist) or a purpose-built speed pedelec that’s designed for higher speeds with better brakes, tires, and motor cooling. That’s the safer and more reliable path than derestricting a bike that wasn’t built for it.

Do all e-bikes have a speed limiter?

Nearly all consumer e-bikes sold in the U.S. do, because manufacturers must comply with the three-class system to sell through major retailers. Some high-end European speed pedelecs ship without a limiter, but they’re not street-legal in the U.S. without registration.

Removing the speed limiter is a mechanical task with legal and safety consequences that go far beyond the wiring. If you decide to do it, use the least invasive method that works for your controller, test on private property first, and be honest with yourself about whether your brakes, tires, and riding environment are ready for the extra speed.