The ASI BAC4000 controller is a high-power motor controller built for the Sur Ron Light Bee X electric dirt bike. It arrives as a complete plug and play kit. You remove the original Sur Ron controller and connect the new one in its place. No soldering is required, and no wiring modifications are needed.
Every kit includes the BAC4000 controller, your chosen display, controller mounting brackets and the connection cables. The wiring harness and brackets are made specifically for the Light Bee X. Therefore, no extra adapters are needed during the swap. Installation is done with ordinary hand tools and without cutting a single wire.
This controller works across a wide voltage range, from the original 60 V battery up to a 72 V pack delivering 250 A. Before ordering, you select your display and your battery type. Based on that choice, the unit ships pre-configured for 5000 W, 7200 W, 12 kW or 14 kW peak power.
Key Benefits
- Plug and play installation – the stock Sur Ron controller comes off and the BAC4000 connects without soldering.
- Power adjustment via display – you change output directly through the 750C or EggRider V2 screen.
- Percentage-based assist levels – assist settings are defined as a percentage, so tuning stays precise.
- Adjustable wheel size – enter your exact wheel diameter and speed readings become more accurate.
- Motor protection – the controller prevents the motor from overheating during hard riding.
- Battery protection – power is reduced automatically as the pack drops under load.
- Wide voltage range – suitable for both 60 V and 72 V batteries.
- Selectable speed units – readings display in km/h or mph.
Who Is This Kit For?
This upgrade kit is made for the Sur Ron Light Bee X. The harness and brackets match that model, so the original controller swap needs nothing extra. It suits riders who feel the factory power is not enough off-road.
Above all, it fits people who ride motocross-style trails and want more torque at the rear wheel. It also suits Sur Ron owners who already run a bypassed pack or a dedicated 60 V or 72 V battery. Your configuration choice depends entirely on the battery you have.
With the original 60 V battery, the controller is set to 5000 W. With a bypassed 60 V battery, it is set to 7200 W. With a 60 V pack delivering 250 A, output reaches 12 kW. Finally, with a 72 V pack delivering 250 A, output reaches 14 kW.
What’s in the Box?
- 1x BAC4000 controller
- 1x display of your choice – 750C or EggRider V2
- 1x set of controller mounting brackets
- 1x set of connection cables
Technical Specifications
| Model | ASI BAC4000 |
| Type | Motor controller, plug and play kit |
| Compatibility | Sur Ron Light Bee X |
| Supported voltage | 60 V – 72 V |
| Config with 60 V original battery | 5000 W |
| Config with 60 V bypassed battery | 7200 W |
| Config with 60 V / 250 A battery | 12,000 W (12 kW peak) |
| Config with 72 V / 250 A battery | 14,000 W (14 kW peak) |
| Display options | 750C or EggRider V2 |
| Power adjustment | Via display, assist levels in percent |
| Protections | Motor overheating protection, battery protection |
| Speed units | km/h or mph |
| Installation | No soldering, no modifications |
| Original rear sprocket | 48 teeth (64 teeth maximum) |
Why Choose the ASI BAC4000?
With a bypassed battery, the power increase reaches 75-90 %. As a result, the rear wheel gains noticeably more traction and acceleration. Top speed also climbs compared to the stock setup.
With a dedicated 60 V or 72 V pack, output rises by 180-300 %. That is roughly double the power, traction and acceleration at the rear wheel compared with a bypassed battery. However, the actual speed gain depends on your rear sprocket. The stock sprocket has 48 teeth, and 64 teeth is the maximum that can be fitted.
The controller arrives fully prepared for use. Moreover, it supports several display types, so you adjust settings without any additional equipment or laptop software.
Frequently Asked Questions
Does the ASI BAC4000 fit the Sur Ron Light Bee X?
- Yes, the kit is built specifically for the Sur Ron Light Bee X.
- The harness and brackets are made for that frame and mounting points.
Do I need to solder or modify anything?
- No soldering and no modifications are required.
- Installation uses ordinary tools, with no wire cutting.
Which display should I choose?
- You can select either the 750C or the EggRider V2.
- Both let you set power output and assist levels in percent.
What battery do I need for 14 kW?
- A 72 V battery capable of delivering 250 A is required.
- A 60 V pack at 250 A gives 12 kW instead.
Will it work with my original 60 V Sur Ron battery?
- Yes, the controller is then configured for 5000 W.
- A bypassed 60 V pack raises that figure to 7200 W.
How much extra power will I actually gain?
- A bypassed battery gives a 75-90 % increase.
- A dedicated 60 V or 72 V pack gives 180-300 %.
Do I need extra adapters for the Light Bee X?
- No, the connection cables plug into the stock wiring.
- The controller brackets also match the original location.
Can I change the speed readout units?
- Yes, speed shows in km/h or mph.
- You can also enter your exact wheel size for accuracy.
Choose your display and battery type before ordering, and the ASI BAC4000 arrives configured for your Sur Ron Light Bee X. From there, you fit the controller, connect the harness and set your assist levels through the screen. The result is more torque at the rear wheel, stronger acceleration and full control over how much power you release.
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