ASI BAC 4000 Controller For Sur Ron, 60V (for Bypass mod) Moto X Club Version with: Loom and Voltmeter


Moto X Club 60V Version: (bypass mod) ASI BAC 4000 Controller For Sur Ron with: Loom and Voltmeter

Out of stock


Moto X Club 60V Version: (bypass mod) ASI BAC 4000 Controller For

Sur Ron with: Loom and Voltmeter

Set for bike with a STD 60v Sur Ron battery and Battery Bypass

Higher Volts, Higher Amps Higher RPM+  Higher Speed !

More acceleration and more top end.

Delivery time is now up to three weeks if showing on back order, in stock three days, as we deal with demand. – Thank you

Designed for the Sur Ron Battery with or without bypass mod battery. See our other listing for battery Mod Bypass here:

Set for bike with a standard 60v Sur Ron battery with the  Battery Bypass mod ( we offer the mod in the batteries section). This will be too powerful for a standard un modified battery and a little pointless to spend this much money on a bike with a standard battery!

We wanted to bring a slightly cheaper but more robust version of the controller with no stupid gadgets and updates. This version simply bolts to the bike and uses the existing throttle. Add the handlebar ebike built volt meter, to tell you your battery state and your ready to go. Expect a shock as the 7000 watts to kicks in!!!

We figure when you buy a motocross bike, you dont sit there looking at a speedo, most don’t even have a rev counter (why do you need this on an electric bike?) You dont turn your power down just because your running out of fuel on a gas bike, you just go gentle on the throttle – same here! If you want to know your speed then stick a bicycle GPS on the handle bar or strap your smart phone to it (you can let your little sister or mum call you too), but when you want to go fast in the woods, with nothing to break and no updates or silly flashing colour screens, take the phone away and you ready to race.

Two power modes: Full (7200W and 4800W)

Your Sports /Eco button will still give full power 7200w or eco mode @4800W (this my be in reverse – button markings only,  due to programming wiring limits)

I ride my bike like this but with a bigger rear cog 56T and I’m 20 stone, I still have to lean forward to stop the wheel coming up!!

We highly recommend changing the rear cog to 55T or 56 T, 60T is mental to 45+mph and experience the blistering improvement in acceleration. This reduces strain on the battery and increase the range but you will lose a bit of top speed. But the bike will still hit 45mph top end (or more) but becomes a real trail power woods bike.

Set at the same power as its slightly big brother the 8000, This controller performs almost identically at 60V, but will choke back from heat if uprated later to the higher 72V power settings and go above 12000 watts . This controller is designed for much higher power outputs than the 4000. The 8000  finds these power setting extremely easy to handle and with much better cooling. The 8000 is able to convert more DC amps to phase amps than any other ASI controller. We make the same profit by selling either controller, but just cant see the point of the slower 4000 on this race set up, but in our opinion the sheer superiority of the 8000 makes buying the 4000 less future proof.

Power sets from

7200 with upgrade with standard but bypass modded  60v standard battery (we feel this is the limit for the bypass mod)


Controller Feature Set

  • FOC (Field Oriented Control)
  • improved torque throughout the rev range
  • Higher RPM compared to the stock controller on 60V and especially on 72V
  • Silky smooth throttle control and responsiveness.
  • Improved efficiency due to FOC algorithm, premium internal components within the controller (like the mosfets) which increases efficiency while reducing heat losses
  • Automatic sensored to sensorless transition which gives you addition 5% top speed and better performance
  • Usable voltage is 60V nom (48v – 67V
  • Loom
  • Mounting Kit
  • Install Instructions
  • Volt meter


we recently after a long relationship broke away from a well known Californian business who supplied us these controllers. We found the latest display supplied by them was simply to difficult for most users with features that caused too many issues.

Now: no updates, no messing and no home made display cases.

Unfortunately this set up will not allow the simple swapping of battery voltages. You have to choose your battery voltage and stick with it. We will however change this voltage for you free one time only by appointment via remote session on your laptop with a Bafang programming lead. So if you buy the controller to run on a 72v battery and then for whatever reason go back to the 60V Sur Ron power battery, the motor will still work

The handlebar voltmeter will show full at 67v , half way at 60v and motor stop at 48v. So at 53v under load start nursing the throttle. Remember its the displayed voltage when your under power, is the voltage that  counts, not sitting in the paddock or down the pub

Sorry but we will not be supplying any Bluetooth codes.

This set up is too much for a standard battery without the “Bypass Mod”

Bypass can be found here:


We now offer a fitting service

Different location around the county.

Each location has different working patterns. Generally the bike will need to be dropped of at prior arrangement and collect one working week later. but must include a full weekend in between.

Price £229 and not included with the original controller purchase.

Current fitting locations are:

Braunton Devon (Electroncycles)

North Wales (Baglit – Fitter),

North Leads (Otley – Fitter)

Telford (fitter)


ASI Controller Sur Ron Fitting Service (Epsom near M25 JNCT 9)

Self Fitting:

This is a plug and play system, but we now believe there are at least three slightly different version of the Sur Ron Lightbee motor. This can cause some minor issues. Because of this we now include 1 hour free remote support during our working hours (9 – 5.30 Mon-Friday and Saturday morning by appointment). We strongly advise that you factor in our working hours when fitting. We will not give support outside these hours. To give remote support you will need either an iPad or iPhone and good internet connection.


Battery Bypass Mod @£189 (just click on the picture/link):

Sur Ron Battery “Mod” BMS direct discharge Service


UK Warranty 

* 6 Month Warranty is for manufacturing defaults and does not cover miss use or accidental damage. These units are extremely strong and robust and will not let you down unless abused. We undertake warranties here in the UK. We take the pain!

Please note, Lithium batteries are considered hazardous and due care and attention should be taken. Although these cells are in wide use, and professionally manufactured in a purpose built factory; because of the power of the battery, we strongly recommend that precautions are taken. We do not recommend charging inside the family home and charging should be supervised. We take no responsibility for misuse. These batteries are thoroughly tested (full discharge and charge cycles at the manufacturing stage and also pre-delivery). These are not DIY or amateur built devices.

We reserve the right to slightly modify or change this product without notice.



Buyer releases Electron Cycles or any person trading on or behalf of the business known as Electron Cycles from any liabilities, therein known as Electron Cycles (expressed or implied, arising by law or otherwise) that may occur from the use of products sold by Electron Cycles and purchased by Buyer. These products are being sold for “Off Road/Competition Use” only and may be used only on two wheel vehicles (bicycles, electric bicycles, two wheel electric powered vehicles) used solely for “Off Road/Competition” (off-road being defined as a private land with land owners permission and not public highway or byway). The Buyer also recognises that Lithium batteries are classed as hazardous and should not be: stored, used, charged in place, facility any area that is not fire proof or safe to do so. That batteries should not be taken into the family home, office, workplace or school place. No other applications are intended or implied. The Buyer of product sold or provided by Electron Cycles acknowledges and agrees that Seller disclaims any warranty and expressly disclaims any liability for personal injury or damages or any damages to vehicle, expensed occurred, personal property or third persons. Electron Cycles will uphold the warranty of the manufacture of the product sold for a minimum of six months from date of purchase from manufacturer defect. In the event a manufacturer’s warranty exists, it is agreed and stated that Under no circumstances shall the seller or manufacture be liable for any labour charged or travel time incurred in diagnosis for defects, removal, or reinstallation of this product, or any contingent expenses.







Additional information

Weight 3.5 kg
Dimensions 40 × 25 × 25 cm