The ASI BAC4000 controller kit is a complete electronic drivetrain upgrade for the Sur-Ron Light Bee X and the Segway Dirt eBike X160 and X260. At its core sits a programmable ASI BAC4000 FOC motor controller that replaces the stock unit. Alongside it, the kit includes a 750C or EggRider V2 display, controller mounting brackets and the connecting wiring.
The factory Sur-Ron controller delivers 4,800 W. With the BAC4000 fitted, output is tuned anywhere from 5,000 W up to 15,000 W, depending on your battery. That is roughly three times the stock figure. Importantly, the motor and battery stay factory – only the electronics change.
The kit runs on both 60 V and 72 V battery systems. Installation is plug-and-play, so no soldering or wiring modifications are needed. Every controller is programmed individually, which means the settings are matched to your specific drivetrain and battery pack.
Key Benefits
- Individual software tuning – an engineer configures each controller, so you receive a bespoke map rather than a generic factory preset.
- Up to 15 kW output – replaces the stock 4,800 W ceiling with as much as 15,000 W on a 72 V system.
- 60 V and 72 V compatibility – works with the factory pack and with upgraded battery setups alike.
- Installation without modification – the stock controller is simply swapped for the new one, with no soldering required.
- Power adjustment from the display – output is changed directly through the 750C or EggRider V2 screen.
- Assist level in percentage steps – the assist setting is tuned in percentage increments to suit your riding style and terrain.
- Motor overheat protection – the system monitors motor temperature and reduces output when needed.
- Battery wear protection – power is automatically lowered at a low state of charge.
Who Is This Kit For?
This kit is built for three machines specifically: the Sur-Ron Light Bee X, the Segway Dirt eBike X160 and the Segway X260. These are lightweight off-road electric motorcycles without pedals. Consequently, the kit is not intended for electric bicycles or scooters.
Riders typically choose it once the factory 4,800 W no longer feels sufficient off-road. The extra torque is felt at the rear wheel from the moment you pull away. Acceleration improves noticeably, while top speed depends on the rear sprocket you have fitted.
Because output reaches 12-15 kW, a machine set up this way belongs on closed tracks and off-road terrain. The kit also suits riders planning to move to a 60 V or 72 V pack later, since the controller supports both voltages.
What’s in the Box?
- ASI BAC4000 motor controller with individual software tuning
- Control display – 750C or EggRider V2 (selectable)
- Controller mounting brackets for frame installation
- Connecting wiring for solder-free installation
- Controller heatsink – available as an optional extra
Technical Specifications
| Controller model | ASI BAC4000 (FOC, sine wave) |
| Compatible machines | Sur-Ron Light Bee X, Segway Dirt eBike X160, Segway X260 |
| Battery voltage | 60 V – 72 V |
| Power: 60 V stock | 5,000 W |
| Power: 60 V with bypassed BMS | 7,200 W |
| Power: 60 V custom tune | 12,000 W (12 kW) |
| Power: 72 V custom tune | 15,000 W (15 kW) |
| Factory machine output | 4,800 W |
| Display | 750C or EggRider V2 |
| Installation | No soldering or modifications |
| Speed units | km/h or mph |
| Wheel size setting | Adjustable for accurate speed readout |
| Protections | Motor overheat, battery wear |
| Kit contents | Controller, display, brackets, wiring, heatsink (optional) |
Why Choose This Controller Kit?
Most power upgrade kits arrive with pre-loaded settings written for an average machine. This one does not. Each ASI BAC4000 is programmed individually, so the parameters reflect your actual drivetrain and battery combination.
The BAC4000 is a FOC, sine wave controller, which is why torque delivery stays smooth rather than abrupt. Meanwhile, the 750C or EggRider V2 display keeps the useful settings in reach: output level, assist percentage, wheel size and speed units in km/h or mph.
Two safeguards run in the background as well. Motor temperature is monitored continuously, and output drops if it climbs too high. Likewise, power is trimmed automatically when the battery reaches a low charge level.
Frequently Asked Questions
Does this kit fit the Sur-Ron Light Bee X?
- Yes. The Sur-Ron Light Bee X is one of the three machines this kit is designed for.
- The stock controller is removed and the BAC4000 takes its place.
Will it work on a Segway X160 or X260?
- Yes. Both the Segway Dirt eBike X160 and the Segway X260 are supported.
- The same brackets and connecting wiring are included for these models.
How much power does the BAC4000 deliver?
- Output is tuned between 5,000 W and 15,000 W.
- A 60 V custom tune reaches 12,000 W; a 72 V custom tune reaches 15,000 W.
- The factory machine produces 4,800 W by comparison.
Do I need to solder anything during installation?
- No. The kit is plug-and-play and uses the supplied connecting wiring.
- No wiring loom modifications are required.
Which battery voltages are supported?
- Both 60 V and 72 V packs work with this controller.
- You can therefore keep the factory pack now and upgrade later.
Do I have to replace the motor or battery?
- No. The motor and battery remain factory items.
- Only the electronics are changed.
Can I change settings while riding?
- Output level and assist percentage are adjusted from the 750C or EggRider V2 display.
- Wheel size and speed units in km/h or mph are set there too.
Is a heatsink included?
- The controller heatsink is an optional extra rather than a standard item.
- Brackets and wiring are included as standard.
With individual programming, dual voltage support and up to 15 kW on tap, the ASI BAC4000 kit turns a stock Light Bee X, X160 or X260 into a considerably stronger off-road machine. The swap is reversible, since the original controller simply comes off. For closed-track and off-road use, few electronic upgrades change the character of these bikes so directly.
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