Building An Off-Road Electric Bike: A Step-By-Step Guide

Electric bikes are a great way to get around, and with conversion kits, you can add power to your own bike at a fraction of the cost of a new e-bike. There are a few things to consider when choosing a kit, such as the type of kit, the cost, and the installation process. The three main types of kits are front hub, rear hub, and mid-drive, each with its own pros and cons. The cost of the kit and batteries is also an important factor, as batteries can be expensive and may need to be replaced every few years. When installing the kit, you may need to remove the crank to fit the pedal sensor, and you will also need to attach the cadence sensor, battery, and LCD display. With the right kit and some time and effort, you can build your own electric bike for off-road use.

Choosing the right kit for your bike

Firstly, understand the three main types of e-bike conversion kits: front hub, rear hub, and mid-drive. Front hub kits involve swapping the front wheel with one that has a motor at its centre. This is a good option if you want to avoid the bulkiness of a mid-motor setup. However, it is important to note that not all bikes are compatible with this type of kit; it usually requires a bike with a front disc brake and a quick-release axle. The rear hub kit is similar but involves swapping the rear wheel. This type of kit is a good option if you want to keep your bike's front wheel unchanged, perhaps for better steering control. The mid-drive kit, on the other hand, involves installing a motor beneath the pedals, in the bottom bracket of the bike. This type of kit is ideal for those who want to tackle steep hills and off-road terrain, as it offers high torque.

When choosing a kit, it is crucial to consider the compatibility of the kit with your bike. As mentioned earlier, front hub kits are not compatible with all bikes, and the same is true for other types of kits as well. Check the specifications of the kit to ensure it will fit your bike's frame and wheel size. Additionally, consider the power and range you will require. If you plan to ride on hilly terrain or go off-roading, you will need a kit with higher power output and a larger battery capacity. Speaking of batteries, they are another critical component of your e-bike setup. It is recommended to invest in high-quality batteries from reputable brands like LG, Panasonic, or Samsung. While cheaper options may be tempting, they often have diminished capacity, voltage, and longevity, and can sometimes be unsafe.

Finally, consider your level of mechanical expertise. Some kits are easier to install than others, and if you are new to working on bikes or electrical systems, opt for a kit with good customer support and simple instructions. Additionally, consider the cost of the kit and its components. Factor in the price of the kit itself, the batteries, and any other necessary parts. Remember that the cheapest option may not always be the most cost-effective in the long run, especially when considering ongoing expenses such as battery replacements.

By carefully considering these factors, you can choose the right e-bike conversion kit for your off-road adventures.

Sourcing and installing the battery

Sourcing a battery for your electric bike kit can be a complex process, and it is important to be cautious. While it may be tempting to opt for a cheaper battery, this can be a false economy, with poor performance and safety issues being common. Reputable battery makers use high-quality cells from brands like LG, Panasonic, and Samsung. A good rule of thumb is to look for a 36V battery, with wattage ratings of 300-600 watts. The Swytch eBike kit, for example, offers a range of power pack options with different specifications and quantities of lithium cells, providing various range options.

When sourcing a battery, it is also important to consider the type of motor you are using. If you are using a mid-drive motor, which is better for off-road conditions and hilly terrain, you will need to ensure the battery is compatible. The Bafang mid-drive system is a good option, offering compatibility with a wide range of bike designs and high torque for steep hills. The TongSheng mid-drive is another option, offering similar benefits to Bafang but in a lighter package.

Once you have sourced your battery, the next step is to install it. The installation process will depend on the type of battery and the bike frame. It is important to ensure that the battery is installed securely and that the wiring is tidy. All batteries are removable, allowing for easy charging, and the controller, which collects energy from the battery and distributes it to the rest of the kit, can be attached to the battery or independently.

When installing the battery, it is also important to consider the other components of the kit. The controller, for example, should be easily accessible for troubleshooting. The PAS sensor, which warns the engine to provide energy, and the brake sensor, which reinforces the braking, will also need to be installed. Finally, it is important to test the kit to ensure that all electrical circuits are closed and functioning properly.

Compatibility and safety considerations

Compatibility and safety are crucial considerations when building an electric off-road bike kit. Here are some detailed guidelines to ensure a safe and compatible setup:

Compatibility Considerations:

• Wheel and Motor Compatibility: When installing a motor at the wheel's hub, ensure the wheel's diameter, width, and axle standard match the kit's specifications. Check if your bike uses rim or disc brakes and choose a kit accordingly.
• Bike Design: Opt for a kit that is compatible with your bike's design. For example, the Bafang mid-drive system and TongSheng are known for their compatibility with a wide range of bike designs.
• Battery Compatibility: Ensure the battery fits your bike's specifications, including voltage, watt hours, and amps. Check the shape, size, and connector type for a proper fit and connection.
• Crank and Chainring Compatibility: Some kits, like the TongSheng mid-drive, require replacing the crank and chainring with the provided components. Ensure these are compatible with your bike's setup.
• LCD Display: Some kits, such as the TongSheng, include an LCD display for the handlebars. Ensure this is compatible with your bike's existing setup and doesn't obstruct other components.

Safety Considerations:

• Battery Safety: Never compromise on battery quality to save money. Buy from reputable manufacturers and dealers to avoid substandard batteries that could be dangerous and damage your bike.
• Battery Swapping: When swapping batteries, ensure compatibility with your bike to prevent damage or fire hazards. Avoid using batteries with different voltage or ampere-hour ratings, as they may overload your bike's electrical systems.
• Legal Compliance: Check your local laws and regulations regarding electric bikes. Some jurisdictions may have specific requirements or restrictions for electric bike conversions.
• Reinforcement: The added weight of the electric kit may require reinforcing certain areas of the bike, such as the fork, to handle the additional force.
• Waterproofing: Consider waterproofing the electronic components, as some kits have connectors that are not waterproof.

Cost and savings calculations

The cost of building an electric bike from a kit varies depending on the type of kit, the bike you already have, and your specific needs. The price of the kit itself can range from a few hundred dollars to almost $1,200. For example, the Voliamart rear wheel kit is an affordable option, while the Ride1Up Roadster V2 kit costs around $1,095.

In addition to the cost of the kit, you will also need to factor in the cost of the battery, which can vary depending on the type and quality you choose. Sealed lead-acid batteries are the cheapest option, while more expensive options include batteries from reputable brands like LG, Panasonic, and Samsung. It's important to note that cheaper batteries may be disappointing and even dangerous, so it's recommended to buy from a dealer with an established presence and return policy. The cost of the battery can be about half the cost of the conversion kit itself, and it may need to be replaced every two years, so it's a significant expense.

Other costs to consider include any additional parts or accessories you may need, such as a special mount to make the battery fit, or a plastic enclosure to protect the electronics. You may also want to factor in the cost of electricity, repairs, and maintenance, which can add up over time.

Building an electric bike from a kit can offer significant savings compared to buying a pre-built electric bike, which can be quite expensive. By repurposing an existing bike and adding an electric boost with a conversion kit, you can get many of the benefits of an electric bike without the high price tag. Additionally, you have the freedom to customize your bike to your specific needs and preferences, which may be more cost-effective than buying a pre-built electric bike with features you don't need or want.

Legal implications of conversion

The legality of converting a conventional bicycle into an electric bike varies across different jurisdictions. It is crucial to understand the legal implications and regulations surrounding these modifications before purchasing an electric bike conversion kit.

In the United States, the Secretarial Order set forth the policy that electric bikes should be allowed where other, non-motorized types of bicycles are permitted and prohibited where non-motorized bicycles are not allowed. The Bureau of Reclamation has also amended its regulations to define electric bikes as having two or three wheels, fully operable pedals, and an electric motor that does not exceed 750 watts (one horsepower). Electric bikes are classified into three classes based on their maximum speed and power output, which determine where they can be ridden.

In the United Kingdom, electric bike conversion kits, such as Swytch, are generally legal as they comply with electric bike laws. However, it is important to purchase from a reputable company to ensure compliance. Aftermarket kits may not meet the required standards, and using a non-complying kit could result in legal consequences under the Road Traffic Act. It is also worth noting that converting your bicycle may void its warranty, so checking the terms and conditions is essential.

It is important to research and understand the specific regulations and laws in your jurisdiction before converting your bicycle. Some kits may exceed legal power limits or fail to meet safety standards, posing safety hazards and resulting in legal consequences. Poorly executed conversions can introduce safety risks, such as faulty wiring or compromised stability. Therefore, meticulous adherence to installation instructions and regular maintenance are crucial to ensure a safe riding experience.

Frequently asked questions