Sur Ron -Controller Upgrade Kit-

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Controller kits are now back in stock, lead times are now dramatically reduced to a week or less. New Color LCD Display coming soon.



72V Sur Ron drop-in battery is now avaliable from our trusted battery builder and supplier. We have been working with LiteSpeed closely and thus our ASI BAC controllers have been finely tuned and optimized with their high quality battery packs. 




Sur Ron User Manual has been overhauled and updated



Major Update

Controller line-up has been changed, BAC2000 is now available as the base controller on the Sur Ron kit. 


ASI BAC2000 - 225A Peak Motor Current - Suitable if using factory 60V battery and can use 72V+ Battery upgrade but wont be achieve full performance of the motor 
ASI BAC4000 - 463A Peak Motor Current - Suitable for factory 60V Battery and 72V+ Battery upgrade




Eggrider V2 - Compact Minimalist Display, with Bluetooth connectivity and its own mobile app.

    • Standard readouts such as odometer, trip meter, clock, battery voltage, battery % remaining, and range estimation. 
    • Secondary readouts include wattage, current, and efficiency (watt hours and watt hours consume per mile).
    • Adjustable power / speed modes (Assist) to allow quick and easy power mode selection to vary the power / speed output when needed.
    • Ride Summary Report / Graphing / and mobile phone dashboard feature
    • Display turns on automatically with the bike when key is switched on.

Performance Enhancement with the ASI BAC Controllers

Stock 60V Battery - The BAC controller with the 60V Battery map will extract maximum power / current from the Sur Ron’s factory battery pack just short of tripping the current limit on the Battery’s BMS (Battery Management System). Extensive testing with the Sur Ron’s stock 60V battery with the ASI’s datalogger. 




  1.            Easy
  • Plug and Play and Easy to Install 
  • Plugs into the OEM harness and connectors, everything bolts on for a true play and plug install.
  • Keeps Original Throttle
  • Controller mounting bracket, bolts onto frame without modifications
  • Eco / Sport mode selector is now at: 2500W / 6000W respectively
  • Retains factory functions (Key Switch, lighting, USB charger, etc)


  • FOC (Field Oriented Control) for smooth throttle control and response, high efficiency,
  • Regenative braking that is variable using a second throttle for precise regen braking control, saves significantly on brake pad wear, and increases range by converting braking force and sending energy back into the battery.
  • Much more aggressive power, higher peak motor current compared to stock Sur Ron, improved starting torque and acceleration.
  • Higher top speed due to field weakening. Original controller would slow down nearing top speed, where as Field Weakening allows the motor to gain additional 1000rpm. 
  • Controller operates in Hybrid mode (Uses hall sensors for smooth starting, then transitions to sensorless, increasing efficiency and gain in top speed)
  • Sensorless fallback mode in case the hall sensors were to fail
  • Can fully utilize regen (Sur Ron BMS will cut at full charge, however ERT has found a solution for this by limiting regen power at full charge and gradually increasing then restoring full regen power at battery % reaches 95%.
  • Controller is highly water resistant as is the high quality harness that has been designed in house by ERT to be reliable under all terrain environments.
  • Controller has automatic thermal rollback protection for the controller and the motor. 
  • Motor RPM has increased from 5500rpm to 7000rpm.

                 Color Display

  • Color TFT Display is avaliable, with additional 3 mode power selection. Speedometer, ODO, Voltage, Wattage, Clock, etc

                Future Proof

  • Usable up to 92V 463A when battery upgrades are available 

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