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Convert a compatible bicycle with power delivered through its existing gears. KirbEbike mid motor conversion kits combine responsive torque sensing with 500W, 750W and 1000W options for hills, trails, touring and higher-load riding. Compare the TSDZ8 and Z16 below, then check your bottom bracket and battery space before ordering.
Every pack ships with its matched charger and mounting kit.
Both motors use torque sensing and drive through the bicycle's chain and gears. Choose the TSDZ8 for a lighter, lower-cost build or the Z16 when maximum torque and battery capacity matter more.
A compact 4.8kg mid-drive with torque and cadence sensing. The TSDZ8 is the practical choice for riders who want responsive climbing assistance without moving to the heavier 1000W platform.
The higher-output option for steep off-road climbs, heavier riders, cargo and demanding terrain. It combines torque, cadence and speed sensing with up to 160Nm and an optional 48V 30Ah battery.
Compare the specifications that affect fit, ride feel and range. Published range figures are estimates, not guarantees; terrain, rider weight, tyre pressure, speed, temperature and assist level all matter.
| Specification | TSDZ8 500W / 750W | Z16 1000W |
|---|---|---|
| Best for | Value-focused conversions, lighter builds, hills and trail use | Steep terrain, heavier loads, cargo and high-demand off-road builds |
| Rated voltage | 36V or 48V, depending on motor option | 48V |
| Motor power | 500W or 750W | 1000W |
| Maximum torque | Up to 140Nm | Up to 160Nm |
| Pedal sensing | Torque and cadence sensing | Torque, cadence and speed sensing |
| Motor weight | Approximately 4.8kg | Approximately 6kg |
| Bottom bracket | Designed for common 68/73mm threaded shells | Designed for common 68/73mm threaded shells |
| Battery choices | 36V 15Ah, 48V 20Ah or motor-only options | 48V 30Ah battery or motor-only option |
| Estimated range | About 30-70km, depending on battery and use | About 50-80km with the 48V 30Ah battery |
| Charging | 2A charger with battery bundles | 5A charger with the 48V 30Ah bundle |
Simple choice: select the TSDZ8 when lower weight, price and everyday versatility are your priorities. Select the Z16 when you need the strongest climbing support and can accommodate the larger motor and 48V 30Ah battery.
A mid-drive replaces the bicycle's bottom bracket and crank area rather than its wheel. That changes how power reaches the ground and how the converted bike feels.
The system measures pedal force and adds assistance in proportion to your effort, giving smoother starts and more intuitive control than a basic cadence-only system.
Motor power passes through the chain and rear gears. Selecting a lower gear can help the motor climb efficiently instead of forcing it to pull at low speed in a high gear.
Positioning the motor low and centrally can preserve more balanced handling than placing a heavy motor in the front or rear wheel.
A mid-drive does not require a motor wheel, making it useful when you want to keep a particular rim, tyre, hub, cassette or wheel size.
High torque and the ability to use lower gears make a mid motor kit a strong option for steep routes, trails and heavier-load riding.
Compatibility depends mainly on the bottom bracket and frame clearance, not whether the bicycle uses 26-inch, 27.5-inch, 29-inch or 700C wheels.
Do not order by wheel size alone. Mid motor compatibility starts at the bottom bracket, then depends on frame shape, chainstay clearance, chainline and battery space.
Many mountain, hybrid, touring and cargo bicycles with a suitable 68/73mm threaded bottom bracket can be converted. Wheel diameter is not the main restriction because the motor sits at the crank.
Carbon frames, press-fit bottom brackets, unusual chainstay shapes and internally routed cables require extra caution. Send clear photos and measurements to KirbEbike support before ordering if any part of the fit is uncertain.
Always inspect the bicycle's frame, brakes, drivetrain, chain and tyres before adding motor power. A worn or damaged donor bike should be repaired before conversion.
Voltage must match the selected motor system, while battery capacity affects range, weight, size and charging time. Do not connect a battery simply because the plug looks similar.
| Motor option | Recommended bundle | Energy | Published range | Charger |
|---|---|---|---|---|
| TSDZ8 36V 500W | 36V 15Ah battery | 540Wh | Approximately 30-50km | 42V 2A |
| TSDZ8 48V 750W | 48V 20Ah battery | 960Wh | Approximately 35-70km | 54.6V 2A |
| Z16 48V 1000W | Taishan 48V 30Ah battery with LG 21700 cells | 1440Wh | Approximately 50-80km | 54.6V 5A |
Already own a battery? Confirm nominal voltage, full-charge voltage, BMS discharge capability, connector type, polarity and physical dimensions before choosing a motor-only kit. Browse KirbEbike battery options or contact support when compatibility is unclear.
A mid-drive conversion requires more mechanical work than swapping a hub-motor wheel. Use the correct crank and bottom bracket tools, follow the motor instructions and ask a professional mechanic when you are unsure.
Inspect the frame and drivetrain, remove the pedals and crankset, then remove the existing bottom bracket.
Insert the drive unit, check frame clearance and chainline, then secure the fixing plate and lockring to the specified torque.
Fit the cranks, display, speed sensor, brake cut-offs and other selected controls, then route cables away from moving parts.
Secure the battery, verify polarity and connections, test at low assistance, then recheck fasteners, brakes and shifting after the first rides.
Protect the drivetrain: shift to an easier gear before a climb, reduce pedal pressure while changing gear, keep the chain clean and lubricated, and replace a stretched chain before it damages the cassette or chainring.
Motor power and assisted speed affect how a converted bicycle is classified, and the rules differ by country and region. Product availability does not mean every configuration can be used as an ordinary pedal cycle on public roads.
In Great Britain, a standard EAPC must have pedals, a motor with no more than 250W continuous rated output, and assistance that stops above 15.5mph. A converted bicycle outside those limits is not treated as a normal EAPC and may require approval, registration, tax, insurance, a licence and an approved helmet.
The 500W, 750W and 1000W configurations on this page are therefore not standard UK road-legal EAPCs. Use them only where lawful, such as private land with the landowner's permission, or complete the required vehicle approval and registration process. Read the current GOV.UK electric bike rules before riding. Outside the UK, check your national e-bike and motor-vehicle regulations before riding on public roads.
Answers to the fit, battery, riding and maintenance questions customers most often need to resolve before choosing a kit.
A mid motor conversion kit replaces the bicycle's crank and bottom bracket area with a centrally mounted electric drive. The motor sends power through the chain and rear gears, allowing the rider and motor to use the bicycle's gear range.
A hub motor drives the front or rear wheel directly, while a mid-drive powers the bicycle through its chain and gears. Mid-drives usually provide a more central weight position and can use lower gears for climbing. Hub kits are often mechanically simpler to install and place less motor power through the bicycle's chain and cassette.
Both systems are designed for common 68mm or 73mm threaded bottom bracket shells. You must also check the shell's inner diameter, motor-to-frame clearance, chainstay and chainring space, chainline, cable routing and battery mounting area. Press-fit, carbon and unusually shaped frames should be assessed before ordering.
Choose the TSDZ8 500W or 750W when you want a lighter 4.8kg drive, lower purchase cost and strong torque-sensing assistance. Choose the Z16 1000W when steep terrain, cargo or heavier loads make its 160Nm output and optional 48V 30Ah battery more useful. Always check local laws before selecting motor power.
A torque sensor measures how hard you press on the pedals. The controller then adjusts assistance in response to that effort, so light pedalling receives less support and harder pedalling receives more. This generally feels more natural than assistance triggered only by crank rotation.
Yes. Motor-only options are available, but an existing battery must match the motor's nominal and full-charge voltage, current requirement, connector, polarity and physical mounting space. Ask KirbEbike to confirm compatibility before connecting an existing pack.
Published estimates range from approximately 30-70km for the TSDZ8 bundles and 50-80km for the Z16 with its 48V 30Ah battery. Real range changes with rider and cargo weight, climbing, speed, tyre pressure, temperature, surface, gear selection and assistance level.
They are not standard EAPCs for UK public-road use. A standard EAPC is limited to no more than 250W continuous rated motor output and must stop assisting above 15.5mph. Higher-power conversions may be treated as mopeds or motorcycles and can require vehicle approval, registration, tax, insurance, a driving licence and an approved helmet.
Check motor fasteners, cranks, chainring, connectors, brake performance and battery mounting regularly. Keep the chain clean and lubricated, avoid shifting under heavy motor load and monitor chain wear because a mid-drive sends both rider and motor power through the drivetrain.
Compare the lighter TSDZ8 500W/750W system with the high-torque Z16 1000W system, then confirm your bottom bracket and battery space before ordering.
