TOOJUN 36V Electric Bicycle Conversion Kit Review

In the UK, where cycling is both a practical commuting solution and a beloved pastime, the shift to electric bikes (e-bikes) has gained momentum—yet buying a new e-bike can feel like a costly leap. For riders who already own a reliable bicycle, a conversion kit offers a smarter, more affordable alternative: transforming a trusted frame into an e-bike with all the benefits of electric assistance, minus the price tag. The TOOJUN 36V Electric Bicycle Conversion Kit—available in 250W, 350W, and 500W variants, with a 28-inch rear wheel for the 500W option—stands out as a versatile, user-friendly choice for anyone looking to upgrade their ride without starting from scratch.

Power & Performance: Tailored to Your Needs

At the core of this kit is a brushless, toothless rotary fly hub motor—a design choice that prioritizes efficiency, quiet operation, and low maintenance. Brushless motors eliminate the wear-and-tear of carbon brushes, extending the motor’s lifespan, while the toothless (gearless) hub reduces friction, ensuring smooth, near-silent performance. No more loud whirring or clunky gears—just a subtle boost that lets you focus on the ride.

The three power options cater to distinct use cases, making the kit adaptable for urban commuters, hill dwellers, and mountain bikers alike:

250W: Ideal for flat urban routes (think London or Cambridge). It delivers a gentle, consistent boost that takes the edge off long rides, letting you arrive at work refreshed rather than sweaty. Perfect for riders under 180 lbs or those who stick to smooth tarmac.
350W: A mid-range workhorse for moderate hills (like those in Sheffield or Edinburgh). It tackles inclines without forcing you to stop and push, making it a top pick for riders carrying panniers or living in hilly areas.
500W: The kit’s powerhouse. Designed for mountain bikes or riders over 200 lbs, it provides enough torque to climb steep trails or carry heavy loads. The 28-inch wheel size maintains a natural ride height, so you won’t need to adjust your bike’s geometry.

All variants support a maximum weight of 220 lbs (100 kg)—covering most adult riders—and the motor’s efficiency translates to longer battery life, a critical factor for daily commuters. “I converted my old road bike with the 350W kit, and my commute time dropped from 45 minutes to 25,” said Sarah, a Bristol-based commuter. “It’s gentle enough for flat roads but strong enough for the hills near my house. Perfect.”

Smart Accessories: Usability & Safety First

The kit’s accessories are engineered for intuitive use and UK road safety—two priorities for riders navigating busy cities or rural lanes.

LCD6 Meter: Clear, Essential Data

Mounted on the handlebar, the LCD6 is a compact, backlit display that shows four critical metrics at a glance:

Battery Percentage: Eliminates range anxiety—you’ll always know if you have enough juice to make it home.
Current Speed: Helps you stay compliant with the UK’s 15.5 mph e-bike speed limit (and avoid fines).
Total Mileage: Tracks how far you’ve ridden with the kit, great for maintenance or fitness goals.
Single Trip Distance: Perfect for errands or weekend rides, so you know exactly how far you’ve gone.

The display is legible even in bright sunlight (a must for summer commutes) or low light (early mornings or evenings), and the buttons are large enough to press with gloves—essential for UK winters. “The LCD screen is a game-changer,” said Emma, a Birmingham nurse. “I used to rely on my phone for battery checks, but now everything’s right in front of me. No more guessing.”

Thumb Throttle: Familiar, Ergonomic Control

Unlike some kits that force you to replace your grip (a major annoyance for seasoned riders), this thumb throttle attaches to the side of your existing handlebar grip. It’s ergonomically shaped, so your thumb rests naturally on it—no strain during long rides. Use it for a quick boost at traffic lights, to climb hills, or just to cruise without pedaling. “I love that I didn’t have to change my grip,” said Tom, a Leeds student. “My bike still feels like mine, but with a secret superpower.”

Power Cut-Off Brake Levers: Safety as Standard

UK roads demand reliable safety features, and these brake levers deliver. The moment you squeeze the brakes, the controller detects the signal and instantly cuts power to the motor—preventing the motor from fighting against your brakes (a common hazard with cheaper kits). This gives you complete control in emergencies, whether you’re avoiding a pothole or a suddenly opening car door. “The brake levers gave me peace of mind,” said Lisa, a London commuter. “In busy traffic, knowing the motor stops when I brake is priceless.”

Pedal Assist Sensor (PAS): Natural, Efficient Riding

The PAS mounts on your bike’s crank and detects when you’re pedaling—triggering the motor to provide a seamless boost. You don’t have to hold the throttle constantly; just pedal like normal, and the motor helps you along. It’s more energy-efficient than using the throttle alone (extending your battery range) and feels far more intuitive than purely throttle-based systems. “The PAS is my favorite feature,” said Dave, a retired Cambridge teacher. “It feels like I’m still cycling, but with a helper. I don’t get tired as quickly, so I ride more often now.”

Durability: Built for UK Roads

UK roads are notorious for potholes, gravel, and rain—so a conversion kit’s build quality is non-negotiable. The TOOJUN kit uses premium materials to ensure longevity:

Double-Wall Aluminum Alloy Rim: A premium feature usually found on high-end e-bikes. The double-wall design makes the rim dent-resistant (critical for hitting curbs or potholes) and lightweight (so it doesn’t weigh down your bike). Aluminum is also corrosion-resistant—perfect for the UK’s rainy climate.
High-Carbon Steel Spokes: Thicker and stronger than standard steel, these spokes are tensioned evenly during manufacturing to keep the wheel “true” (straight) even after heavy use. No more adjusting spokes every few weeks!
Sealed Hub Bearings: The motor’s hub uses sealed bearings to keep out water and dirt—extending the motor’s life and reducing maintenance.

“I’ve had this kit for six months, and the wheel still looks brand new,” said a Newcastle user who rides on gravel roads weekly. “I’ve hit potholes that would have bent my old rim, but this one doesn’t even have a scratch. The spokes are still tight, too—no wobble at all.”

Easy Installation: No Mechanic Required

One of the kit’s biggest selling points is its DIY-friendly design. Most users report finishing the conversion in 1–2 hours—even if they’re not “handy” with tools. The kit includes:

A detailed instruction manual (with step-by-step diagrams).
Labeled cables (so you won’t mix up connections).
Basic tools (like hex keys) for assembly.

Here’s a simplified breakdown of the process:

Remove your old rear wheel: Flip your bike upside down (or use a stand) and take off the rear wheel.
Install the motor wheel: The motor wheel uses the same axle size as most bikes—just slide it into the dropouts and secure it with the quick-release skewer.
Connect the controller: Attach the controller to your bike’s frame (using zip ties) and connect it to the motor, battery (not included), throttle, and brake levers.
Mount accessories: Attach the LCD6 meter, thumb throttle, and PAS (to the crank).
Test and adjust: Turn on the battery, pedal to activate the PAS, and tweak the throttle sensitivity if needed.

“I’m not great with tools, but I followed the manual and had it done in 45 minutes,” said Rachel, a Cardiff first-time user. “The cables are labeled clearly, so I didn’t mix anything up. My friends couldn’t believe I did it myself!”

If you get stuck, TOOJUN’s customer support is responsive—most users report getting email replies within an hour, complete with photos or diagrams. “I had a question about the PAS wiring,” said James from Liverpool. “Support sent me a step-by-step guide with pictures, and I fixed it in 10 minutes. No stress at all.”

Versatility: Fits Most Bikes

The kit works with 90% of regular bicycles (road bikes, hybrids) and mountain bikes—as long as your rear wheel size matches (28-inch for the 500W option). It’s ideal for:

Commuters: Convert an old road bike to beat traffic and save money on trains or fuel.
Errand Runners: Carry groceries or parcels without breaking a sweat (the thumb throttle helps with heavy loads).
Mountain Bikers: Add power to your hardtail for steep climbs—you’ll ride further and have more fun.
Recreational Riders: If you’re returning to cycling after an injury, the PAS helps you build stamina without overexerting yourself.

“I converted my 10-year-old hybrid bike with the 350W kit,” said an Oxford user. “Now I ride to work every day—no more trains, no more traffic. It’s saved me hundreds of pounds this year. And the motor is so quiet, I can still enjoy the birdsong on my way home.”

What’s Included (and What’s Not)

Before buying, it’s important to know what’s in the box:

Included:

Motorized rear wheel (28-inch for 500W).
Intelligent controller (manages power flow to the motor).
Thumb throttle.
Power cut-off brake levers (front and rear).
Pedal Assist Sensor (PAS).
Cable ties (for securing the controller).
Instruction manual.

Not Included:

A 36V lithium-ion battery. You’ll need to buy this separately (we recommend a 10Ah–15Ah battery for a range of 15–30 miles). This is a common choice for conversion kits—it lets you pick a battery that fits your budget and range needs. Look for a waterproof case (critical for UK rain) and a USB port (to charge your phone on the go).

Minor Drawbacks (Easily Fixed)

No product is perfect, but the TOOJUN kit’s flaws are minor:

Manual Depth: Absolute beginners might want more photos, but YouTube tutorials fill this gap.
PAS Sensitivity: Some users report the PAS is a little too responsive at first—but you can adjust it via the controller’s settings.
Battery Cost: While the kit itself is affordable, a good battery adds to the total cost. However, this is standard for conversion kits and lets you choose a battery that suits your needs.

These issues are negligible compared to the kit’s overall value. Most users say the pros—ease of use, power, durability—far outweigh the cons.

Customer Feedback: 5-Star Consistency

The kit has a 5-star rating on Amazon, with reviews highlighting three key strengths:

Ease of Installation: “I installed this in an hour—no mechanic needed.”
Quiet Power: “The motor is so quiet, I forget it’s there until I need it.”
Durability: “It’s held up to potholes, rain, and weekly rides for six months.”

“I converted my mountain bike with the 500W kit, and it’s a game-changer,” said Mike from Edinburgh. “The motor pulls me up steep trails like they’re flat. I used to avoid hills; now I look forward to them.”

Another user, Dave from Cambridge, summed it up: “This kit turned my old bike into a new favorite. I ride more often, I’m happier, and I save money. What more could you want?”

Final Verdict: A Smart Investment for Riders

The TOOJUN 36V Electric Bicycle Conversion Kit is an excellent choice for anyone looking to upgrade their bike without buying a new e-bike. It offers:

Flexible power options for every rider.
Durable materials that stand up to UK roads.
Usable features (LCD6, PAS, thumb throttle) that make riding easier.
Easy installation (no mechanic required).
Responsive support for peace of mind.

Whether you’re a daily commuter, a mountain biker, or someone who just wants to ride more, this kit delivers. It’s a cost-effective way to join the e-bike revolution—and the positive reviews speak for themselves.

ASIN: B0BD6FFXL8