Assembly of electric bicycles

Bike Maintenance Guide


Dear friends, thank you for choosing VARUN among many e-bike brands.

VARUN E-Bike is dedicated to providing people with a safer, more comfortable, and environmentally friendly way of traveling. We prioritize functionality, design, quality, and customer experience. Our goal is to offer top-quality products at competitive prices while providing exceptional service. Choosing VARUN won't disappoint you.

Upon receiving your VARUN e-bike, please send your order number and bike's serial number (located on the frame head tube) to our support center at We will activate the 15-month warranty for your e-bike.

We also encourage you to share your riding experience and suggestions with us. We continuously work to improve our e-bikes and provide an enjoyable riding experience to our customers.


 I. Warm Tips: Please Read the Manual Before the First Ride


  1. Before riding, carefully read this manual and check the integrity of the parts to ensure your safety. If you encounter any issues, please contact us promptly at
  2. Always wear a helmet when riding an e-bike.
  3. Please keep both keys in a safe place.
  4. Fully charge your e-bike's battery before riding.
  5. Always respect pedestrians.
  6. Avoid riding in wet environments as the e-bike may slip, causing injury. Moisture can also damage electronic components and void the warranty.
  7. Observe local laws and regulations regarding electric bicycles.
  8. Do not disassemble or modify the parts on your own. If replacements are needed, please contact us to purchase standard parts.
  9. Avoid prolonged exposure to sunlight or rain. Store your e-bike in a place with controlled temperature and without corrosive gases to prevent damage to plated parts and painted surfaces.
  10. To maximize range:

   - Use the pedal-assist mode.

   - Brake sparingly while maintaining safety.

   - Avoid overloading.

   - Before riding, check tire pressure and ensure it is within the recommended range (typically between 35PSI-65PSI or 280KPA-450KPA).

  1. E-bikes carry inherent risks, so follow road rules carefully. In emergencies such as riding at excessive speed, brake the rear wheel first, then the front wheel. Sudden braking of the front wheel can cause falls, so ride cautiously.
  2. Prior to riding, thoroughly inspect the e-bike's condition. You are responsible for any consequences resulting from improper operation or use of the e-bike.
  3. Each e-bike has a unique frame number located in the head tube position. Upon receiving the e-bike, record and store the frame number as we don't keep records of it.
  4. Comply with local laws and regulations. If local laws prohibit the use of speed control handles (also known as throttles), do not install or use them on VARUN brand products. Any consequences will be at your own risk, and VARUN brand will not assume responsibility.
  5. Before your first ride, ensure that all parts and screws of your e-bike are securely tightened (wheel clamps, saddle clamps, etc.).


If you have any further questions or require assistance, feel free to contact our support team. Happy riding with your VARUN e-bike!


II. All Models of Varun Electric Bicycles


Warm Tip:

- If your weight is under 130kg, you will have a better riding experience.

- The speed and range of the e-bike may vary depending on factors such as road conditions, weather, and rider weight.


III. Regarding E-Bike Installation:


When you receive the product, carefully check the list of accessories. Prioritize safety during the installation process and follow the steps below to assemble the vehicle.

Note: The installation steps may vary slightly depending on your specific e-bike model. Please refer to the corresponding installation steps for the model you purchased. To ensure your safety, wear protective gloves before installation. Do not disassemble or modify the e-bike without permission, as it may result in permanent damage or personal injury.

(1) Handlebar Installation:

  1. For Envoy | Envoy-S | Envoy-Pro Model:

- Insert the upper part of the handlebar riser into the lower part, ensuring the retaining structure is locked in the middle.

- Stand the riser vertically and lock the folders at the bottom of the riser.

- Confirm that the handlebar structure is secure and doesn't wobble.

 Note: When adjusting the height of the handle riser, do not exceed the limit line!

  1. For Sleeper | Sleeper-S Model:

- Remove the protective plug and insert the handlebar riser against the frame head tube, ensuring it exceeds the minimum insertion depth marked on the handlebar riser vertical tube. Then tighten the screw.


  1. For Altus Model:

- Install the handlebar into the stem, align the fork, and tighten the screws.


  1. For Altus-27.5'' | Altus-Pro | Altus-24'' | Ballistic Model:

- Turn the handlebar cross tube 180 degrees to face forward and tighten the two bolts using a No.2 (M4 wrench) tool to secure the handlebar in place.


(2) Adjusting the Handlebar Angle:

  1. For Envoy | Envoy-S | Envoy-Pro Model:

- Adjust the handlebars to the desired position and then secure the handlebar riser using the quick-release clamp ring.


  1. For Sleeper | Sleeper-S | Altus | Altus-24'' Model:

- Adjust the angle of the handlebars and tighten the screws.


  1. For Altus-27.5'' | Altus-Pro Model:

- Use a No.2 (M4 wrench) tool to unscrew the four bolts from the stem cover.

- Rotate the handlebars until they are perpendicular to the bike frame.

- Tighten the stem cover against the handlebars and reinstall the four bolts.

- Finally, tighten the screws using a No.2 (M4 wrench) tool.


(3) Front Wheel Installation:

For all models listed:

- Use a No.8 (M17 wrench) tool to loosen the fork retaining bar and remove it (this accessory prevents fork deformation during delivery).

- Place the front wheel into the forks, ensuring the fork hangers are secured to the axle and the disc is positioned in the middle of the brake.

- Tighten the flange nuts on both sides using a No.7 (M15 wrench) tool.


(4) Fenders and Lights Installation:

  1. For Envoy | Envoy-S | Envoy-Pro | Sleeper | Sleeper-S Model:

- Loosen the screws at the corresponding positions of the front wheels.

- Position the fender and re-tighten the screws.

- Attach the headlights, adjust their position, and then tighten the screws.

- Loosen the screws holding the baffle, secure it, and re-tighten the screws.



(5) Pedal Installation:

For all models listed:

- Ensure that the threads of each pedal are fully inserted into the crank arm.

- Use a No.7 (M15 wrench) tool to fully tighten the pedals.

- Note: Turn the pedal labeled "L" counterclockwise into the left crank and the pedal labeled "R" clockwise into the right crank.



(6) Saddle Mounting:

- Connect the seat and seatpost first.

- Insert the seatpost into the bar receiver, adjust its position, and find the suitable height for your riding preference.

- Tighten the seat with the clamp.

- Note: Do not exceed the maximum saddle height or raise it above the safety line.



(7) Tail Light/Rear Reflector Installation:

  1. Taillight Installation (Envoy | Envoy-S | Envoy-Pro | Sleeper | Sleeper-S Model):

- Remove the taillight, install it on the rack, and tighten the screws.

- Connect the plug of the taillight cable and secure the cable to the rack using a tie wrap.


  1. Rear Reflector Installation (Altus-27.5'' | Altus-Pro | Altus-26'' | Altus-24'' | Ballistic Model).


(8) Battery Installation:

  1. For Envoy | Envoy-S | Envoy-Pro | Sleeper | Sleeper-S Model:

- Insert the battery into the center of the frame and lock it with the battery key.

- Ensure the battery switch is on for an enhanced riding experience.

- To remove the battery, insert the battery key, turn it to the unlock position, and then remove the battery.


  1. For M26-3 Model:

- First, install the battery pouch on the handlebars.

- Then, pull out the power cord connector from under the pouch.

- Locate the power cord connector and connect it to the battery's power cord connector to complete the installation.


  1. For Altus-27.5'' | Altus-Pro | Altus-26'' | Altus-24'' Model:

- Open the battery compartment and place the battery at the correct angle.

- Gently insert the battery into the holder until it locks automatically.

- Insert the key into the keyhole and rotate it to align with the "OFF" icon to lock the battery, preventing removal.


(9) Adjusting the Brake Levers, Gauges, Shifter, Throttle, and Bell on the Handlebars:

- Adjust the angle of each component as desired.

- Tighten them using a suitable tool.


Completing the above steps indicates successful installation.