But buying a brand-new e-bike can be a costly investment. That’s where electric bike conversion kits come in — a smart, cost-effective solution that allows riders to upgrade their existing bicycles into powerful e-bikes. With the right kit, you can retain the comfort and setup of your current bike while enjoying electric-powered speed, torque, and longer range.
Enter KirbEbike, a performance-driven brand offering some of the most advanced ebike conversion kits in the UK. From powerful 72V 4000W kits built for fat-tire off-road beasts to efficient 250W commuter-friendly options, its brings a professional-grade upgrade path to every rider. In this guide, we’ll explore the top 10 best e-bike conversion kits available in the UK and help you find the perfect match for your riding goals and budget.
What to Look for in the Best Electric Bike Conversion Kit
Choosing the best electric bike conversion kit isn’t just about power—it’s about balance, compatibility, and ride experience. Whether you're converting for daily commuting or high-performance riding, here are the key features to consider:
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Motor Power (Watts)
Motor wattage directly impacts your e-bike’s speed and torque.
- 250W–750W: Ideal for city commutes and legal compliance.
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1000W–3000W+: Built for speed, off-road power, and hill climbs
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Battery Compatibility & Voltage
Match your kit with a compatible battery voltage (typically 36V, 48V, 52V, 60V, or 72V).
Higher voltage = greater power, range, and efficiency. It offers integrated kits for perfect pairing.
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Wheel Size Compatibility
Most kits support common sizes (20"–29"). Ensure your chosen kit matches your bike’s frame and brake type (disc or rim).
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Installation Time
Choose a plug-and-play kit with minimal wiring. This kits are designed for 30-minute DIY installs with detailed guides.
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Pedal Assist & Throttle Options
Look for PAS sensors for assisted pedaling and throttles for pure electric boost. KirbEbike kits offer both.
Top 10 Electric Bike Conversion Kits in the UK Market
1. Kirbebike’s 72V 4000W Extreme Performance Kit (55MPH+)
Ideal for: Mountain bikes, fat tire bikes, and thrill-seekers who demand maximum torque and speed.
If you're looking for raw power, unmatched torque, and off-road dominance, Kirbebike’s MTX PRO 4000W Kit is the crown jewel of high-performance conversion kits. With a peak speed of 55+ MPH, it transforms your MTB or fat tire frame into an electric beast.
Product Highlights:
- Motor Power: 4000W peak, 110Nm torque
- Battery: 72V 20AH LG/Samsung cells, 800+ cycle life
- Speed: 55+ MPH max (80–90 km/h off-road)
- Range: 40–80 km per charge
- Charging Time: 4hr 35m fast charge
- Wheel Options: 26", 27.5", 29", and 20/26" fat tire variants (135mm, 142mm, 175mm, 190mm dropouts)
Built for Pros:
- Advanced 60A FOC Controller with 18-MOSFET design for ultra-precise throttle response
- 3.5" TFT Display with speed, trip, PAS levels & battery indicators
- Cruise Control and 6KM/h Walk Assist Mode
- Weatherproof & Thermal-Protected components
2. Kirbebike's 60V 2500W–3000W MTX Rim Kit (45MPH+)
Perfect balance of power and reliability
Great for: Trail riders, fast commuters, and performance-focused urban users.
The MTX PRO 3000W Kit offers a solid upgrade for riders seeking higher torque and speed without sacrificing durability or ease of use. With peak speeds of 45+ MPH and military-grade waterproofing (IP66), it's built to handle everything from trails to wet weather commutes.
Highlights:
- Motor Power: 2500W–3000W peak
- Battery: 60V 20AH LG cells with 71.4V full charge
- Speed: Up to 45+ MPH
- Range: 40–80 km per charge
- Controller: 50A sine wave controller with thermal protection
- Wheel Options: Wide range from 20" to 29", including fat tires (175mm & 190mm dropouts)
- Display: PAS control with throttle and cruise support
- Legal Mode: 250W/25kmh limiter toggleable via display
3. Kirbebike's 52V 2600W MTX Rim Kit
Mid-range performance with premium features
Best for: Aggressive commuters, hilly terrain, and riders seeking a powerful yet practical solution.
With 2600W of motor output, this 52V kit strikes a sweet spot between speed and efficiency. Paired with a 52V 30AH battery, riders can expect an extended range of up to 100 km while hitting top speeds around 50–60 km/h.
Highlights:
- Motor Power: 2600W
- Battery: 52V 30AH Lithium with 5A fast charging
- Speed: 50–60 km/h
- Range: 50–100 km
- Wheel Compatibility: Multiple sizes (26"–700C) with cassette or freewheel thread options
- Motor Weight: 6.8kg
4. Kirbebike's 52V 2000W MTX Rim Kit
Solid performance for daily use
Best for: Riders upgrading from 500W–1000W kits, casual commuters wanting more torque.
Offering reliable power and great speed at 50–60 km/h, this 2000W kit is ideal for daily commuters who want better hill-climbing power without going overboard. Its S6 color display, thumb throttle, and electric brake lever offer responsive control.
Highlights:
- Motor Power: 2000W
- Battery Options: 52V 20AH or 52V 30AH Lithium
- Speed: 50–60 km/h
- Range: 40–80 km
- Controller & Display: S6 color display, 1T4 waterproof harness, V12 PAS
- Wheel Compatibility: 26", 27.5", 28", 29", 700C
- Legal Mode: 250W/25kmh toggle via display
5. Kirbebike's 1500W–2000W Fat Wheel Kit
Best for rugged off-road rides and sand/snow trails
Great for: Riders with fat tire bikes needing powerful torque and terrain versatility.
Tailored for fat-tire compatibility, this kit brings up to 2000W of motor power and a 52V battery system for sustained performance on sand, snow, or steep inclines. With a 4.0” fat wheel setup and 7-speed freewheel support, this is your go-to for all-terrain adaptability.
Highlights:
- Motor Power: 1500W–2000W
- Battery Options: 52V 20AH / 30AH Lithium
- Speed: 50–60 km/h
- Range: 40–80+ km
- Wheel Compatibility: 20” or 26” fat tires (175mm / 190mm dropouts)
- Display & Controls: LCD8IF color display, electric brake, thumb throttle
- Waterproof Design: 1T4 cable harness, V12 PAS
6. Kirbebike’s 500W & 750W MTX Rim Kits
Lightweight, efficient, and urban-friendly
Best for: Beginners, casual riders, and lightweight commuters.
These mid-range kits offer a sweet blend of power and efficiency, with either 500W or 750W motors that can comfortably handle daily city rides and moderate hills. With multiple wheel size options and compatible 36V or 48V 16AH batteries, these kits are perfect for first-time e-bike conversions.
roduct Highlights:
- Motor Power: 500W or 750W
- Battery Options: 36V/48V 16AH Lithium
- Use Case: Urban commuting, light trail use
- Wheel Sizes: 20", 26", 27.5", 28", 29", 700C
- Affordable & reliable performance
7. Kirbebike's 48V 1000W Kit (Standard Wheel)
Budget-friendly performance
Best for: Commuters, casual e-bike riders, and road bike conversions.
This 1000W conversion kit provides excellent value with 48V power and a simple setup for standard bike wheels. It’s reliable for paved roads, moderate inclines, and offers enough torque for a fun commute.
Product Highlights:
- Motor Power: 1000W
- Battery: 48V 16AH Lithium
- Top Speed: Around 40–50 km/h (estimated)
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Wheel Sizes: 26" to 29", 700C
8. Kirbebike's 48V 1000W All-Black Wheel Edition
Sleek styling + proven performance
Best for: Style-conscious commuters, road riders
With the same reliable performance as the standard 1000W kit, this version features a stealthy all-black motor wheel for a more streamlined look. Great for e-bike enthusiasts who want a modern, discreet aesthetic without sacrificing power.
Product Highlights:
- Motor Power: 1000W
- Battery: 48V 16AH Lithium
- Wheel Sizes: 28", 29", 700C
- Same performance, upgraded styling
9. Kirbebike's 36V/48V 250W Front Wheel Kit
Fully legal for UK/EU road use
Best for: City commuters, folding bikes, and hybrid users
Designed to meet EU/UK regulations with a 250W motor, this front-wheel kit transforms nearly any standard bike into a legal electric commuter. Available with 36V or 48V 16AH batteries, it provides great assist for flat cities or short commutes.
Product Highlights:
- Motor Power: 250W (front wheel)
- Battery Options: 36V or 48V 16AH
- Wheel Sizes: 20"–29"
- Lightweight, commuter-friendly, plug-and-play
10. Kirbebike's 250W Front Wheel Kit (No Battery)
Entry-level conversion for city bikes
Best for: DIYers, minimalists, and budget builds
If you already have a compatible battery or are doing a fully custom build, this lightweight 250W front-wheel kit is a great entry point. It's ideal for hybrids and flat-terrain urban rides and offers simple PAS support.
Product Highlights:
- Motor Power: 250W
- Battery: Not included
- Wheel Sizes: 20", 26", 27.5", 28", 29", 700C
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Affordable, clean design, legal performance
How KirbEbike Stands Out from Competitors
When it comes to electric bike conversion kits, KirbEbike doesn’t just offer power—it delivers reliability, engineering precision, and rider-focused value. Here's how it sets itself apart in a crowded market:
Advanced Waterproofing (IP66 Rated)
All KirbEbike kits feature IP66-level waterproofing, meaning your motor and controller are protected against dust, heavy rain, and wet trail conditions. Whether you're riding through a storm or crossing muddy paths, you can trust your system won’t fail.
Premium LG Battery Cells + BMS
Many of KirbEbike’s kits include LG-brand lithium battery cells—known for longevity and stability. Paired with advanced Battery Management Systems (BMS), these batteries resist overcharge, overheating, and deliver consistent output across long distances.
UK-Focused Shipping & Customer Service
KirbEbike emphasizes fast and reliable UK shipping, along with localized customer support. That means less waiting, no customs delays, and smoother post-purchase assistance—something many overseas brands struggle to provide.
Frequently Asked Questions:
Is 250W legal in the UK?
Yes. According to UK and EU regulations, 250W is the legal power limit for electric bikes used on public roads. The motor must also cut out at 25 km/h (15.5 mph) and not require a throttle-only mode (PAS is required). Kits like KirbEbike’s 250W front wheel kits are fully compliant for legal road use.
What battery voltage do I need?
It depends on your riding style:
- 36V or 48V: Ideal for commuting, casual city rides, and legal road use (250W–1000W motors).
- 52V or 60V: Great for higher torque and faster acceleration, often paired with 1500W–3000W motors.
- 72V: Best for extreme performance setups (4000W+), delivering 55+ MPH top speeds for off-road use.
How fast can my bike go?
Speed depends on the motor power and battery voltage:
- 250W (legal): ~25 km/h (15.5 mph)
- 1000W: ~35–40 km/h
- 2000W: ~50–60 km/h
- 4000W: Up to 90 km/h (55+ MPH, off-road only)
Is installation beginner-friendly?
Yes! Most KirbEbike kits are plug-and-play and take 30–60 minutes to install with basic tools. Each kit includes:
- Pre-laced motor wheel
- Controller
- LCD display
- Waterproof wiring harness
- Throttle, PAS, and brake levers
Power Up Your Ride with KirbEbike
Whether you're a daily commuter, thrill-seeking off-roader, or just looking to breathe new life into your favorite bicycle—KirbEbike has a conversion kit built for your lifestyle. From legal 250W front wheel kits to extreme 4000W+ performance systems, every kit is engineered for durability, speed, and intelligent control.
