Unboxing & Assembly

Assembly instructions for CEMOTO D-series electric dirt bikes and CEMOTO eBikes.

Start with the section and video for your exact model. Parts and steps differ between bikes. Have another adult help support the bike. If you are unsure about installing a wheel, handlebar or brake, ask a qualified bike repairer to finish and check the assembly before riding.

Part 1 — Unboxing

Your product ships in a partially disassembled state so that it can travel safely. The frame, motor, controller, wiring harness and battery system are assembled, inspected and tuned at the factory before the bike is partially broken down for shipping.

Step 1 — Inspect the carton before opening

Inspect the outer carton for crushing, punctures, deformation or water damage before you sign for the delivery.

If the carton is visibly damaged, do not sign for or open it — contact CEMOTO support immediately.
Follow the carrier's signature instructions and inspect the carton before accepting it. Once signed for, the package may be treated as accepted.
We recommend filming a complete unboxing video and checking the contents against the packing list. Report anything missing or damaged promptly; claim evidence and deadlines are in the Shipping Policy.

Step 2 — Open and inventory the contents

Cut along the top of the carton. Do not cut deep — the bike and battery may sit close to the surface.
Remove the accessory box and the small-parts pack first.
Locate and set aside: the charger, the pedals, the keys, and the assembly hardware bag.
Check the bottom of the carton and inside the wrapping for loose nuts and bolts.
Keep all packaging material until assembly is complete and the bike runs correctly.

Step 3 — Lift the bike out

With two people, lift the bike out by the frame. Do not lift by the handlebars, the seat or any cable.

Handle with care: The battery is a heavy, dense component located low in the frame. Take the weight at the frame and keep the bike upright.

Part 2 — Tools required

CEMOTO supplies the tools needed for the assembly steps. Pictured assembly kits typically include:

Open-end wrenches
Hex keys (Allen wrenches) — 4 mm, 5 mm, 6 mm and 8 mm are used in the D-series assembly steps
Screwdriver
Cable ties

You will need to supply:

A tire pump with a pressure gauge using a Schrader-type valve
A torque wrench — strongly recommended for final tightening of axle nuts and stem bolts
Thread lubricant or grease for the seat post and pedal threads

Do not inflate tires using a pressurized gas-station air system. Those systems are designed for car tires and operate at much higher pressure and volume than a bicycle tire requires.

Part 3 — D-Series Electric Dirt Bike Assembly

Applies to: D02 Classic · D02 Track · D03 Pro · D03 Beast

The D-series ships roughly 85 % assembled. Four items normally need to be installed:

3.1 Front wheel

Identify the front-left and front-right shock absorbers and the two axle bushings. The long bushing fits the left side, the short bushing fits the right side.
Insert the front wheel between the fork legs, aligning the brake disc with the brake caliper gap.
Pass the front axle through in this order: left shock absorber → left long bushing → front wheel → right short bushing → right shock absorber.
Fit the hexagonal flange self-locking nut and tighten with the corresponding wrench.
Brake disc must sit centrally between the two brake pads. If it rubs, loosen and reposition the caliper.
Spin the wheel — it should rotate freely without lateral play or scraping.

Critical: Self-locking axle nuts must be replaced if they are ever removed and the locking feature is worn. Never reuse an axle nut that no longer resists turning.

3.2 Handlebars

Position the handlebar assembly vertically into the handlebar seat on the upper triple clamp.
Seat the handlebar clamp block over the bar and fit the hexagon socket screws.
Use a 6 mm hex wrench to install and tighten the four clamping screws.
Tighten in a diagonal (cross) pattern to keep the clamp seated evenly.
Apply downward pressure to the bar to confirm it will not rotate or move forward/backward with normal riding force.

Handlebar-mounted controls:

Insert the front brake master cylinder and the throttle grip onto the handlebar in sequence. The brake lever should sit approximately 12° below horizontal.
Align the throttle grip plane with the installation stop line — the zero line — on the grip.
Tighten with a 4 mm hex wrench. Do not overtighten the throttle housing; the throttle must snap back freely when released.

3.3 Front number plate / headlight

Insert the lower tab of the number plate into the hole on the front fender.
Position the plate against the front of the upper clamp.
Fix with the internal semi-circular head bolt and tighten using a 5 mm hex wrench.

On models with the dual-beam headlight, connect the headlight connector and confirm the light operates before final tightening.

3.4 Front fender

Position the front fender vertically onto the lower clamp.
Fit and tighten the hexagon socket pan-head screws with a 5 mm hex wrench.
Apply pressure to confirm the fender is securely fixed and cannot move.

3.5 Front brake pump (caliper) installation

Grasp the front brake lever to seat the caliper pistons, then carefully pull the black transport plug out of the master cylinder.
Pull the plug out of the lower caliper backwards — do not squeeze the lever with the pads removed or the pistons will over-extend.
Slide the caliper over the brake disc so the disc sits centrally between the two pads.
Mount the caliper to the front-left shock absorber with the hexagonal flange bolts and tighten.

3.6 Footpegs, seat and rear shock

Footpegs: Mount into the frame brackets and secure with the supplied pins or bolts. Confirm each peg locks in both the deployed and folded positions.
Rear shock absorber: Seat the shock into the mounting seat on the rear swing arm, pass the mounting bolt through, and tighten. The D-series ships with the rear shock generally in place — verify it is secure.
Seat: Fit and tighten according to the seat mounting hardware. Confirm the seat does not rotate under hand pressure.

3.7 Tire inflation

Confirm the recommended pressure for your model (see the model page in D-Series).
Inflate using a hand pump with an integrated pressure gauge and a Schrader-type valve.
Tires are shipped at maximum PSI for transport and may lose pressure between production and delivery — always check before the first ride.
Under-inflated tires noticeably increase rolling resistance and reduce range. Over-inflation reduces grip on loose off-road surfaces.

Part 4 — eBike Assembly (Commuter, Mountain, Fat-Tire, Folding)

Applies to: EB40 · AEB31A · B28 · B28A · B28D · EB66 · B57A · EM11

eBikes ship approximately 90 % assembled. Pedals, the seat, the front wheel and sometimes the handlebar are loosened or removed for shipping.

4.1 Handlebar and stem

On models where the handlebar is removed or folded down, align the stem with the steerer tube, tighten the stem clamp bolts evenly, then confirm the handlebar is square to the frame. Tighten stem bolts in a cross pattern.

4.2 Front wheel

Insert the wheel into the fork dropouts, seating the axle fully.
Confirm any quick-release lever is fully closed and tight, or that the axle nuts are securely torqued.
Check that the wheel is centered between the brake pads and spins freely.

4.3 Pedals

Important: Pedals are handed. The left pedal is reverse-threaded and tightens anticlockwise; the right pedal is standard-threaded and tightens clockwise. Fitting a pedal into the wrong crank arm will cross-thread and destroy the crank.

Apply a light smear of grease to the pedal threads.
Start both pedals by hand — never force them.
Fit the left pedal into the left crank arm and tighten anticlockwise.
Fit the right pedal into the right crank arm and tighten clockwise.
Finish with the correct wrench and the tightening value specified for your pedal and crank. Do not rely on riding to tighten the pedals. Ask support or a qualified repairer if the value is unclear.

4.4 Seat post and saddle

Apply a light smear of grease to the seat post.
Insert the seat post to the desired height and tighten the seat clamp.
Minimum insertion: never raise the seat post above the minimum-insertion line marked on the post. Exceeding this can crack the frame.
Check the saddle is level and securely clamped.

4.5 Brakes and gears

Confirm the brakes engage firmly before the lever reaches the handlebar, and that the brake lever cuts motor power when pulled. Run through the gears to confirm clean, indexed shifting across the cassette.

If you are not confident adjusting brakes and derailleurs, a local bike shop can complete this in a short visit.

Part 5 — Tightening bolts correctly

Torque means how tightly a bolt or nut is tightened. Use the value in your exact model's manual or component instructions and the correct torque wrench. “Tighten firmly” is not a reliable setting for an axle, handlebar, brake or suspension bolt.

If a value is missing, contact support or a qualified repairer. Do not copy a number from another model, a different part or a general internet table. See Torque & Fastener Reference.

Check that the wheels, handlebar, brakes and pedals are securely installed before the first ride, and re-check after the first ride as your model instructions require. Stop if anything moves or becomes loose.

Part 6 — Assembly videos

CEMOTO publishes step-by-step assembly videos for the most common models:

Video	Applies to
Off-Road Electric Dirt Bike D02 — Unboxing & Assembly	D02 Classic, D02 Track
Folding eBike B57A — Unboxing & Assembly	B57A
How to Install a CEMOTO Motor — Step-by-Step Tutorial	D-series
How to Install the Front Disc Brake on a CEMOTO Electric Dirt Bike	D-series
How to Install CEMOTO Pedals	eBikes
How to install the left and right battery side guards for the CEMOTO D series	D-series

The full video library is cataloged in Technical Guides.

Assembly procedures in this page are derived from the official CEMOTO electric dirt bike owner manual and CEMOTO eBike owner manuals.