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500W–1000W
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EZ Rider Kit
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Free UK Delivery
Easy installation
1-year warranty
Four thousand watts is where corner-cutting gets exposed. Bagged controllers overheat and fail; generic batteries sag under load; 7-speed-only motors force drivetrain swaps. This kit exists because we solved those three failures the expensive way: a 60A controller potted in thermal resin, a Samsung 50S-cell battery that delivers 60A continuously without flinching, and motors that accept 6-to-12-speed freewheels.
The result is a genuine 55+ mph machine for MTB and fat-tyre builds — with a three-second Limit Mode that caps speed and power for gentle riding (full power is for private land; the kit is not road legal in the UK). 800 charge cycles, four-hour charging, and the same 1-year UK-serviced warranty as every kit we make.
Note: Speed capabilities shown are for off-road use only. Always ride responsibly and follow local regulations.
🇬🇧 Fast & FREE UK Delivery
We offer 100% FREE Shipping on all orders within the UK! Your e-bike kit will arrive quickly at your door within 3-5 business days.
🌍 Premium Global Shipping
We also proudly ship to the US, EU, Canada, Australia, Japan, and worldwide. International orders are dispatched via trusted premium carriers (DHL, FedEx, TNT) to ensure reliable service. Shipping rates are transparently calculated at checkout, and most global orders arrive within 5-14 business days (please allow slight delays for remote areas).
📦 Secure Battery Shipping Notice
For maximum safety and faster customs clearance, your e-bike kit and battery will be shipped in two separate, securely tracked packages. Both parcels are fully monitored to ensure they reach you safely.
We stand behind the quality of our kits. Wherever you ride, we’ve got you covered with our 1-Year Global Warranty.
🇬🇧 UK Riders (Full Coverage): Enjoy complete peace of mind with 1-year FREE repair service covering both your entire e-bike system and the battery.
🇺🇸 🇳🇱 US & Netherlands: Includes 1-year FREE repair service specifically dedicated to your e-bike battery.
🌍 Global Support: All international orders are fully backed by our standard 1-year global warranty against manufacturing defects.
If you encounter any issues with your kit or battery, our technical team is here to help! Please contact us directly at support@kirbebike.com.
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
Best For
Motor Power
Full Charged Voltage
Wheel Position
Wheel Size
Bike Compatibility
Top Speed
Range
Battery Required
Battery Included
Installation Level
Brake Compatibility
Waterproof Cables
App Support
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design
72V 4000W Extreme Performance Ebike Motor Kit for MTB and Fat Tire Bike 55MPH+
60V 2500W-3000W MTX Rim Ebike Conversion Kit 45MPH+
52V 2600W MTX Rim Ebike Kit Waterproof Design.
In the individual kit, you get everything you need to DIY your bike into an e-bike.
A 4000W powerful motor wheel, 48V-72V 60Amp FOC sinewave smart controller, 48V-72V TFT color display, 72V 20AH Lithium battery pack, 72V 5A Fast Charger, Twist Throttle with the key Lock, e-Brake levers and a good package with foam to protect all parts be safe.
In addition we provide free sweet service accessories, installation tools and additional parts.
In the individual kit, you get everything you need to DIY your bike into an e-bike.
A 4000W powerful motor wheel, 48V-72V 60Amp FOC sinewave smart controller, 48V-72V TFT color display, 72V 20AH Lithium battery pack, 72V 5A Fast Charger, Twist Throttle with the key Lock, e-Brake levers and a good package with foam to protect all parts be safe.
In addition we provide free sweet service accessories, installation tools and additional parts.
1. MTX 39 Double Wall Aluminum Alloy Strong Rim. Black Color
2. 4000w Brushless Direct Drive Rear Wheel, 6.8kgs weight.
3. Black Paint Spokes anti-rust 12G 2.6mm with copper Nipples.
4. Dropouts: 135-142mm. Two Motors: One is for a 7s threaded sprocket, and The other is for Cassete 8s/9s/10s/11s sprocket.
5. Fit Disc Brake.
6. 55+MPH max speed.
7. CE, ROHS certificates.
1. 84VV Full Charged Voltage
2. 5A Fast Charger is included.
3. Samsung 21700 50S cells
4. USB mobilephone Charging
5. ON/OFF Switch
6. Battery Indicator. Precent.
7. Triangle Black Plastic Case.
1. 48V-72V 60Amp FOC
2. Sinewave 12 mosfets Controller.
3. Waterproof, Glues Inside.
4. Quick Release Cable.
5. Over Heating Protection.
6. Easy to Install with Tape Ties.
1. Color Display Design.
2. Battery Power Indicator.
3. Running Speed, Average Speed, Max Speed.
4. Single Mileage, Total Mileage.
5. PAS Levers, Brake Signal, Throttle Signal.
6. Cruise Function, 6KM/H Walk Function, and so on.
Electric Brake Lever to cut off the power when you press it.
Easy installation、More sensitive 、more stable performance.
The facts that decide whether this kit works on your bike, in one place. Measure first, then order.
No. In Great Britain a converted bike is only road legal (an EAPC) when the motor is rated at 250W continuous and assistance stops at 15.5 mph. A 4000W motor is above that whatever the controller is set to, so this kit is for private land with the landowner’s permission, or for roads only with motor-vehicle registration, insurance and a licence. The Ride Power app does let you cap speed and current for gentle riding, but a software limit does not make the bike road legal. If you need a kit for public roads, choose one of our 250W road-legal kits. Full details: UK legal conversion kit guide.
Typical range varies from 40-80km depending on your riding style. You'll get maximum range when cruising at moderate speeds with pedal assist. Aggressive riding at top speeds (80-90 km/h) will reduce range significantly. Factors like rider weight, terrain, and temperature all affect actual performance.
While we advertise a 50-minute installation time, most experienced riders complete it in 1-2 hours. We provide comprehensive tools and step-by-step video guides. First-time installers may want to schedule 2-3 hours or seek professional help for optimal setup.
It is a rear wheel kit for standard mountain-bike wheels (26"–29" and 700C) with a 135–142 mm rear dropout, and there is a separate fat-tyre edition for 4" tyres. You need a steel or aluminium frame (carbon and ultra-light frames are not suitable), disc brakes, and the included torque arms fitted. Pick the motor to match your gears: 7-speed threaded freewheel or 8–11-speed cassette body (sprockets not included). Measure first with our wheel and dropout guide.
Using premium LG/Samsung cells, expect 800+ charge cycles over a 3-year lifespan with proper care. A full charge takes 4 hours 35 minutes. The intelligent BMS prevents overcharging and monitors cell health. The battery detaches easily for indoor charging.
Yes — there is a dedicated 4-inch fat-tyre edition with the same battery and controller. It is the pick for beaches, snow and soft ground.
The brushless direct drive motor operates quietly compared to geared systems. Military-grade construction and waterproof design ensure durability. Most users report thousands of kilometers without issues when properly maintained.
47–53 mph (75–85 km/h) depending on wheel choice, terrain and rider weight, on private land. The app can cap assistance at any lower speed for gentler riding, but a 4000W motor is not a road-legal e-bike in the UK at any setting.
Regular maintenance includes checking motor connections, ensuring battery contacts are clean, and inspecting the torque arm. The controller and battery systems are sealed and maintenance-free. We recommend periodic firmware updates for optimal performance.
The same as every KirbEbike kit: 1 year, serviced in the UK, US, the Netherlands. High power does not void it — abuse does, so fit the torque arms.
