BBSHD ASI BAC855 72v FOC Controller Upgrade 3250 (Peak) Display, Cover, Loom

£449.00 (price including VAT)

BBSHD ASI BAC855 72v FOC Controller Upgrade 3250 (Peak) Display, Cover, Loom

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International orders 20% (VAT) removed at checkout!

BBSHD ASI BAC855 72v FOC Controller Upgrade 3250 (Peak) Display, Cover, Loom

This is the fastest  BBSHD upgrade solution in the world

Higher Volts, Higher RPM Higher Speed !

* UK Warranty


This purchase the controller will be set to 72v by default (other voltages available on request  – just add a note in your purchase)

International orders will be charged additional shipping (we now ship to EU)

 This is very latest controller with enhanced feature (see photos)

This is truly plug n play and expect GENUINE  speeds of around 45+ MPH (Depending on Battery choice)


Did you ever wish your BBSHD went substantially faster, pulled harder and you didn’t have to be told you can’t buy the controller you want – shush it’s a secret?

This controller has everything: field weakening (allowing higher rpm), totally plug n play and now with tunable PAS via our new Electron Display.

Advanced processing and state of the art allows it to compute much faster and much more accurately than the standard Bafang unit (or any modded Bafang controller). Imagine your first media phone in comparison to the latest iPhone/Android device? – Things have moved on and these Canadian devices have not been designed with penny pinching mass market sales like the original.  All of this makes your  motor pull much harder and release around 15% more speed than a 52v 30A Bafang controller and whopping 100% more power than the standard and go 72v 200% !!!!!!!!! We might add the power is designed to come in without the mechanical snapping lurch of an inferior set up.

These controller have been set up so that it can handle anything from 50A (90 A burst) up to 3250wW depending on voltage (easily within their design). This might mean a little explaining:

We have tested the BBSHD to destruction and on more than one occasion right up to 4500 Watts and learned a few things, real facts and not the odd exception.

Amps create heat, heat weakens the nylon gear and too many watts snap the pinion. So how do we get around this? Simple, know the limits but don’t get too close. Sure these are now nearer the limit, but ridden correctly (let the motor spin and don’t labour in the wrong gear), a reliable ride can still be had. At the lower volts where big amps are needed, we have capped the limit to 2800w @52v and 3250w @72v but as you increase your volts A ludicrous controller at 50A has 2500Watts, but now add 10 -15% improvement through field weakening!

But here it gets even better, Change your battery and go up to 20s 72 V (any voltage form 10S to 20S, 36V -90 V) and the controller takes it (not a Bafang originated 60 V cap). Your watts have now jumped to a dangerous 4200 watts on a “hot” (fully charged battery at 84 V), so we reduce this limit to a safer 3250W, but still so much powwweeeeer!

Now with working brake and gear sensors.

Additional mounting kit (not included) here:

ASI BAC855 Mounting Kit

Power Settings

From customer feed back, we have tried to make the Pedal assist function more sympathetic to your drive train and more cycle usable. The Pedal power is now set at default, with 9 smaller increments. The first 5 levels being very pedal friendly and the last 4 very throttle aggressive. This allows for a smoother take off and more refined pedal experience with each power increment more gradual. Throttle and power are related to the PAS level you are in. So power level one is low, power level 5 is mid way and power level 9 is maximum. These power levels are  tunable by you the customer via the display (instructions sent on post purchase request)

We ship the controller with 9 power levels that can be independently set by yourself via the display. Maximum available power (48/52v) is 28000W and 3250W for 72v set up.

PAS function is available with a choice of up to 3 – 5 – 9 levels via the display.

Now with our latest “Electron ” display allowing you the customer to set the PAS levels

Colour display, watts, speed, choice of power modes

Bafang and Egg-rider displays  DO NOT WORK WITH THIS SYSTEM

The controller is locked to protect our intellectual property


We recommend these batteries:

Hard Case Triangle 72V 17.5Ah, 50A (150A Burst) 1260wH with 4A Charger

Controller Feature Set

  • FOC (Field Oriented Control)
  • improved torque throughout the rev range
  • Higher RPM compared to the stock controller on 48/52V and especially on 72V (Up to 9000RPM)
  • Silky smooth throttle control and responsiveness, like a fine adjustable knob on a light switch.
  • 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 15% top speed and better performance
  • Includes 3D Printed Cover
  • Programmed for 3250W, of Assist levels (Power / Speed Map) are set within the display and will scale accordingly.
  • Dimensions 81mm x 55mm x 39mm
  • xt90 Power Connector
  • Weight 300 grams

The kit includes:


Wiring loom to connect direct to existing BBSHD loom.

Electron tunable display

Motor side cover

This purchase the controller will be set to 72v (other voltages available on request  – just add a note in your purchase). A later change of voltage  can be changed by us on request FOC one time via remotes session or return of the unit to us (you pay postage).

Due to the high power draw of the unit, the display power consumption may not be accurate)


Gearing (video tutorial to follow or call for explanation):

Use a 42T front Chain wheel to “Clam Shell the motor and bring the chain line inbound – we sell a cheap Lekkie clone version)

Reduce your rear cassette size to improve the chain line, removing any gears smaller than 15T and create your perfect centre-line around the 26T/28T rear sprocket (depending on wheel size)

Remove the old 9 -10=11 speed cassette and use the gear range from 15T to lowest gear. We love the  Shimano XT CS-M771-10 speed cassette as shown in the photo. Use spacers to give you a perfect chain line for the gear of your choice. For 27.5 and 29er set ups we recommend a 28T rear gear. For 26″ wheels a 26″ T gear. For fat bikes as big as you can get! (32T +)

If you want to be very smart, you can use a 2.35 mm spacer from your old cassette to space out a 17T as a “Get you home” cog for pedaling or PAS assist in power level 1. But you might have to manually put the chain onto the cog. Use your old derailleur as a tensioner and give your self enough chain (we recommend KMC x10e chains) to move up and down  you have. You will want to adjust your max/min screws so the chain does not slip off the outer sprockets (You may need to change these for longer screws)

Please note our controllers are locked and will stay locked to protect the hours and  hours we spent programming and devolving them. Sorry no exceptions.

The white connector from loom to controller must not be removed or warranty will be voided for water damage.

Photos of rear gears and spacers are not included

Customer review:

Graham C I don’t think the BBSHD is weak as people say. Abuse it yes and something will fail just like any mechanical product. My motor was purchased from Francis Janssen in November 2017. Since then I have completed 7000 miles with approx. half of those miles with a Luna Ludicrous controller fitted. My 20 miles daily commute, downhilling, BMX tracks, trails the lot ! I’ve not touched anything internally on the BBSHD and it’s running better than ever, all these stories of nylon gears failing I’m sure is down to the rider, have some mechanical sympathy and you’ll be fine. As Francis states I have now fitted the ASI 800 running on 72v, I followed his advice, got my chain line in order, correct gearing and 500 miles later she is absolutely flying, a weapon indeed. It’s far exceeded my expectations, high revving, smooth ramp up of power, throttle response, acceleration is crazy compared to the Ludicrous, top speed, all fantastic and so much fun, it does not feel like the motor is working hard. I am extremely pleased. I can thoroughly recommend this conversion and Electron Cycles ( Francis Janssen) for there professional services. Go for it !

* UK Warranty 

Our warranty is limited to 12 months from time of purchase. Due to the use and the nature of this device (Off-Road) and the potential excess  exposure to: water, rain, mud and the possibility to sustained high powered use/abuse, we do not warranty controllers that show signs of damage, excess heat or water penetration. All devices are fully bench tested working with a full working motor before leaving our premises. Any damage caused by your installation is not covered by our warranty. alteration may void warranty. This includes shortening of cables and changing connectors. We highly recommend the use of one of recognized fitters where installation is fully covered.

Any alteration modification to this controller or its subsequent wiring, even cutting the power leads to make shorter will immediately invalidate any warranty. Even battery disconnected, the controller can still maintain current and can still be shorted/damaged. The controllers are waterproof, but can still suffer from water damage through the connector and hence are not covered for water damage.

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 period 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 0.9 kg
Dimensions 25 × 20 × 20 cm