Preparing a Sur-Ron Light Bee: brakes, battery, controller, motor – what's the order?

Preparing a Sur-Ron Light Bee involves increasing the power of a machine where every component has been designed for the original power output. Therefore, the correct approach isn't to start with the most visually impressive component, the motor, but rather with the elements that can handle the increased power: the brakes and the frame, followed by the battery, then the controller, and finally the motor. Here's why, step by step.

First and foremost: the legal framework

The Sur-Ron Light Bee is primarily sold in France in its off-road, non-homologated version. Such a vehicle must be registered, bear an identification number, and can only be used on designated terrain (refer to the "non-homologated motorized vehicles" section on service-public.gouv.fr). A homologated version, on the other hand, loses its compliance as soon as its power is increased. Therefore, modifications are typically made for use on authorized terrain and circuits. Our guide electric motorcycle: homologated or off-road details these rules.

Step 1: Machine condition, brakes, and frame components

Let's start with a thorough inspection: steering system, wheel and swingarm bearings, chain and primary belt tension and wear, tire condition, suspension adjustment, and tightness of all fasteners. A machine that has been ridden hard often has some play somewhere.

Next, the brakes. More power means reaching higher speeds faster, which translates to more energy that needs to be dissipated during each braking event. More powerful calipers, thicker rotors, and aviation-grade hoses that don't expand provide stronger and more consistent braking. In our custom builds, we use Hope Tech 4 V4 brakes with aviation-grade hoses. And appropriate tires for the terrain complete the setup: they are the crucial link for both acceleration and braking.

Step 2: The battery

The battery is the foundation of everything. Its Battery Management System (BMS), the board that protects it, limits the current it can deliver; the battery cells themselves experience a drop in voltage under a high current draw. If you demand more current than the battery can handle, the BMS will cut power during acceleration, or the cells will age quickly and overheat.

A performance battery provides both more energy, resulting in greater range, and a higher discharge current, leading to more usable power. Its size and weight are also important factors. Our guide on upgrading the battery for Sur-Ron or Talaria details these trade-offs. Today, our motorcycle batteries are custom-made in our workshops using branded cells.

Step 3: The Controller

The controller converts the battery's current into the current needed by the motor. It determines the torque at startup, the maximum speed, the throttle response, and the motor braking. The original controller is typically configured for the original power output, and it is often the limiting factor that restricts the performance of the machine.

A more powerful controller must be able to handle the battery's full charge voltage with a safety margin, read the motor sensors, and be configurable through different modes. Our guide on light electric motorcycle controllers explains how to choose the right one. Our own motorcycle controllers come with RageLink: you can sign up for the waiting list.

Step 4: The motor

The original motor can handle a reasonable increase in power, but high current levels cause it to overheat. An overheated motor loses torque and damages its magnets. When you need sustained power, whether climbing hills or riding on a track, a motor designed for that purpose becomes necessary.

Our RM30 motor for Sur-Ron Light Bee is an interior permanent magnet (IPM) motor, which allows for MTPA (Maximum Torque Per Ampere) tuning on compatible controllers. It features Hall sensors, making it compatible with most controllers, and is heat-resistant up to 180°C. It comes with a pulley for the original belt. You can find more details in our guide on how to replace the motor on a Sur-Ron.

Step 5: Transmission and Monitoring

Increased torque at the wheel puts more stress on the primary belt, chain, sprockets, and bearings. After modifications, these components wear out faster and require more frequent inspections. Initial test rides are used to check the motor and controller temperatures, potential cut-offs, and braking performance, gradually increasing the power output.