The Radrunner electric bike comes with a 750-watt geared rear hub motor limited to up to 20 miles per hour out of the box. If you want higher speeds, upgrading to a more robust engine is one way. However, you also need to upgrade the controller and battery to achieve an actual speed increase.
From the smallest RadRunner model to the latest RadRunner 3 Plus, Rad Power Bike Company uses the same foundation and similar performance specifications. If you’re looking to upgrade your Roadrunner motor to a 1500-watt motor or a true’ 750-watt motor, there’s a shocker you may not be ready to hear.
Adding a more powerful motor won’t make you go any faster unless you have upgraded your controller. You also need to upgrade the battery because even a 1500-watt motor on the Roadrunner e-bike won’t do much with the 48-volt battery that comes with the bike.
In this article, I’ll show you the step-by-step process and factors to consider as you attempt to upgrade your Roadrunner motor. But before then, you want to be sure you get a suitable replacement that works with the bike’s components. With this in mind, you want to know RadRunner’s current motor specifications.
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RadRunner’s Current Motor Specifications
The RadRunner 2 operate with a 750W rear hub motor. It is activated with four levels of pedal assist or thumb throttle. This gives you a maximum speed of 20 mph.
It performs similarly to the RadRunner Plus, a Class 2 electric utility bike with a similar 750W motor and 48V, 14Ah battery.
However, the RadRunner 2 Electric Utility Bike is powered by a 250W hub motor and a 5:1 planetary gear reduction.
So if you own any of these models and want to increase the max speed to 25 mph/40 kph, you need to focus on a higher-voltage battery, a new motor, and a better controller.
Many bikers have testified that replacing their batteries with the Bolton 35A controller improved acceleration. Some Speedometers reported 24mph with throttle on flat pavement and 25 to 26mph while pedaling.
Performing the Roadrunner Motor Upgrade
Upgrading your Roadrunner motor can increase the maximum speed from 20 to 25 mph (40 kph). However, you need to make a few other upgrades. Here’s why:
The controller determines the amount of torque and acceleration of the e-bike and sets limits to the maximum speed possible. So even when you have a higher motor (1500w or even 3000w), you need a higher controller.
If you already did the Bolton 35A controller upgrade, you’re good. Anything beyond that will require a whole new system, from battery to motor.
Now, a higher battery voltage can give the motor more potential power. You can put a 3,000W motor on your bike, but you’ll never have more than 1,440W (48V × 30A) of power supplied to your controller if your 48V 14Ah battery is only capable of 30A peak current.
Benefits of Upgrading RadRunner’s Motor
Upgrading the 750W motor on a RadRunner bike to a higher one could be desirable for several reasons:
- Increased power: A higher-wattage motor will provide more power, allowing the Roadrunner bike to handle steeper hills, carry heavier loads, and achieve faster speeds.
- Improved performance: With a more powerful motor, your bike can offer better acceleration and responsiveness, making it more enjoyable to ride.
- Extended range: Depending on the specific motor and battery combination, a higher-wattage motor might lead to improved energy efficiency and, consequently, an extended range.
- Off-Road Capabilities: A higher-wattage motor can provide the necessary torque and performance if your goal is to use the bike for off-road adventures or challenging terrain.
Factors to Consider Before Choosing a Motor Upgrade
First of all, there have been a lot of talks about the Rad’s motor for the Radrunner lately about whether it’s a true 750w or a 500 or 600-watt engine “bumped up” to 750w. Many of these 750w-powered Roadrunners operate like the 500-watt nominal/750-watt peak Bafang motors.
So if you’re considering an Upgrade, it’s either to a true 750w or something higher. Now consider these factors before making such a change:
- 1. Battery capacity: Ensure that your current battery can handle the increased power demand of a 1500W motor. Upgrading the motor without an appropriate battery could reduce the range or cause potential damage.
- Frame and components: Verify if your Roadrunner model’s frame and other details can handle the increased stress of a more powerful motor. A higher-wattage engine might require sturdier construction and better heat dissipation.
For example, you may get the internals into your bike’s hub case and eventually realize that the axle is too long on the chain or plug as you try to drop it into the frame.
- Weight and handling: A larger motor might add more weight to the Roadrunner, affecting its handling and maneuverability. Consider how the upgraded engine could impact your comfort and control while riding.
- Warranty and support: Check the warranty and support for the new motor and any associated components. Understand the terms and conditions of the upgrade and the potential impact on contracts. According to Rad Power Bikes, the Limited Warranty is expressly limited to replacing a defective lithium-ion battery (the “Battery”), motor, throttle, controller, wiring harness, and other components.
- Cost: Upgrading to a higher-wattage motor can be costly. The price varies depending on the brand and model; expect to pay between $160 and $400 for a 1500-watt high-performance kit. And if you’re consulting with a professional, you’ll need to pay for artistry as well.
Key Takeaway
Upgrading the motor of your RadRunner E-bike from 750W to 1500W could increase its power and speed significantly.
However, a higher-powered motor might stress other components more, potentially leading to accelerated wear and tear or reduced battery range.
As you attempt to upgrade the motor for increased max speed, consider upgrading the controller and battery.
