Sur Ron Bypass Bundle: ASI 4000 60v Controller + Bypass Mod + Recovery Controller 7200 Watts

£1,048.00 £999.00

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

5 in stock


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

Sur Ron with: Loom and Voltmeter, Recovery Charger, and Bypass Service.

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

This is an all in one package

Higher Amps, Higher RPM (FW)+  Higher Speed + More Acceleration and more range (30% bigger volt range)


More acceleration and more top end.

You send your battery to us. We bypass the BMS for discharge, map the controller and send the whole kit back to you – ready to fit!

Designed for the Sur Ron Battery with our bypass modded battery. 

Set for bike with a standard 60v Sur Ron battery and with our  Battery Bypass mod.

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 7200 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!!

Range is massive extended by about 30% because of bigger volt range (now goes lower than 54V all the way to a safe 48V)

We highly recommend changing the rear cog to 55T or 56 T, 60T is mental is too much and will make the motor over rev so please let us know to modify the program. 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.

If you later decide t go 72v, we can re-map your controller remotely to bring it up to 13,500 watts and pure mental performance (will need our aftermarket battery).

Power sets from

7200 with upgrade with standard but bypass modded  60v standard battery (we feel this is the limit for the bypass mod). Massive increase in acceleration and top speed by 5-10mph

4800 “Eco Mode”: Your bike will go 30% further than before and about 2-4mph higher top speed- this mode can be set to 30mph for L1E owners that want it to pass the 30mph MOT test.)


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


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.

Sur Ron Battery “Mod” BMS direct discharge Service

You will only see performance gains when used with an after market controller the ASI BAC 2000/4000/8000

For more in email:

We do not recommend this modification being undertaken by the inexperienced individual as risk of fire.

The Sur Ron battery has been designed to have a massive amount of “Redundancy” or “A lot left in the Bank”

Sur Ron built their standard battery with a cell type and configuration to handle a restricted 60 Amps standard,  but the set up with restriction removed  can actually handle 110Amps (The cell manufacturers data sheet  states 11 x 10 A =110Amps).

The battery has a management system known as a “BMS” (Battery Management System). This has various functions: Evenly “Balance” charge the individual cell series that make up the battery. Restrict the output of the battery and stop the battery from being drained to low “LVC” (Low battery Cut off). It simply does this by cutting off the power.

Our ASI controllers are programmed to cut off power before the battery gets too low and not take more power than the battery can handle.

Bypassing the BMS for discharge can make full use of the available power from the Panasonic cells. These individual cells have a combined manufactures continuous rating of 110 Amps. In other words they are designed to handle this amount of power until they go flat. However, they can still handle higher power safely for short periods. We have set the bigger ASI 4000 and ASI 8000 to have a burst of 125A in the “Battery Bypass Mode”. The ASI 2000 can only maintain 90 Amps continuous, within the cell manufacturers 110A.

This may have confused you, but think it like this. A motorbike has a rev limiter: Normal band, yellow band (just for a few seconds), red band (dont enter except for a split second) The motor can rev up just up before in the normal zone without issues, on the Sur Ron  modified equivalent of 110Amps.  Yellow would be up to 125 Amps. Red – the controller wont allow it! Sur Ron have restricted the battery by nearly 50% from 110 Amps to only 60 Amps.

Our work is of the highest quality using copper ring connectors both crimped and the soldered. High quality  silicon 10 AWG cable (x3) to hold the additional load,  Special insulating silicon based sealant (not he stuff you use in your bathroom!) to insulate the connections or high heat tube, doubled and tied. The main join is soldered and not just crimped and everything done is a working environment to stop mistakes or secondary damage from solder drips etc.

The benefits of removing the discharged restriction:

Power (watts) up by 50% (from 4800 watts to 7200 watts)
Balance charging
Significant improvement in acceleration and top speed

Negatives of removing the discharged restriction:

Dangerous to undertake modification.
Must have a modern upmarket controller that can monitor low voltage shut off and DC amps set no higher than 125A.
May void warranties

Battery will not charge below 54V unless  use the recovery charger.

Your fuel gauge percentage will be inaccurate. Use your volt reading for accuracy 67v full, 60v half, 48V about to stop.


You are buying:

ASI 400 controller with loom , voltmeter and mounting brackets.

our bms bypass service (Send us your battery, we send it back to you with the BMS bypassed for discharge but still able to balance charge from 54V)

Our 58v max recovery changer (this allows a low battery to be charged enough for the Sur Ron charger to complete the charge and balance from 54v to 67v).

you are NOT buying a a battery.


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

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