BBSHD ASI 48/52v BBSHD FOC Controller Upgrade ASI BAC855 2800W (Peak) Display, Cover, Loom

£429.00 (price including VAT)

48/52v BBSHD FOC Controller Upgrade ASI BAC855 2800W 750c Display, Cover, Loom

5 in stock



International (not EU) orders 20% (VAT) removed at checkout!

48/52v BBSHD FOC Controller Upgrade ASI BAC855  2800W (peak) 750c  Display, Cover, Loom

This is the fastest 52v BBSHD upgrade solution in the world.

Higher Volts, Higher RPM Higher Speed !

* UK Warranty


This purchase the controller will be set to 48/52v (Please see 72v listing for 72v use)

Choice of two maps: “PAS Friendy” and “Extreme” see below for more details)

International orders wil be charged additional shipping – Sorry No EU Shipping


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

This is truly plug n play and expect RELIABLE speeds of around 40+ MPH (Depending on Battery choice)

You can now choose your power settings Cycle Friendly or EXTREME (Cycle friendly is our default)

Cycle friendly PAS 1200W – Throttle 2800 Peak    or      EXTREME (May damage your motor if  used to long in high power in wrong gear) PAS 2800W Throttle 2800W


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), set maximum amps, set maximum watts, maintain these figures while volts drop, totally plug n play and potted to 100% waterproof (the white connector from loom to controller must be waterproofed by you and we take no liability for water ingress).

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 50A Bafang controller and whopping 100% more power than the standard and go 72v 200% !!!!!!!!!, while still using your standard display! (NB, please see our note about displays). 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 2800W (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 50A but as you increase your volts, we capped the watts to 2800W. A ludicrous controller at 50A has 2500Watts – so does ours, 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 3000 W, but still so much powwweeeeer!

Now with working brake and gear sensors.

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 1200 as default, with 9 smaller increments. This allows for a smoother take off and more refined pedal experience with each power increment more gradual. However, using the throttle will still give peak power levels of up to 2800w on the 52v system. 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.

We ship the controller with 9 power levels choice of two maps (please state which you want at check out notes)

“PAS Friendly” program (default): PAS set at 1200 max watts with 9 power levels jumping 1200/9 Throttle set at 2800W with 9 power levels 2800/9

“Extreme” program (on request): PAS set at 2800 max watts with 9 power levels jumping 2800/9 Throttle set at 2800W with 9 power levels 2800/9

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


750c display Rock Solid reliable – no updates, no programming and no leaky cases.

Now with the latest 750  Display (update in the last few months),

Colour display, watts speed choice of power modes

quick demo:


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

The controller is locked to protect our intellectual property

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 5% top speed and better performance
  • Can use Bafang display (Assist Modes are incompatible at the moment, other readouts would work, but you will only have one assist level which max power / speed)
  • Includes 3D Printed Cover
  • Usable voltage is 36V-92V
  • Programmed for 2800W, # of Assist levels (Power / Speed Map) are set within the display and will scale accordingly. Example Assist 1-3, Assist 1 = 33% Power / Speed. Assist 2 = 66% Power / Speed. Assist 3 = 100% Power and Speed.
  • Dimensions 81mm x 55mm x 39mm
  • xt90 Power Connector
  • Weight 300 grams

The kit includes:

ASI BAC855 36V – 90V FOC 90A

Wiring loom to connect direct to existing BBSHD loom with Anderson Power connectors (please ensure you waterproof the white connector on the controller when) installing)

750c Display (can be used with 72 batteries but controller will need a re-map by us

Motor side cover

This purchase the controller will be set to 48/52v. This can be changed by us on request FOC one time via remotes session if you have a Bafang programming lead

Please note that the Bafang speed sensor was not designed for this unit and can become inconsistent with higher speeds


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.

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 !

* Warranty, due to the nature of use of these devices  (off road) warranty is limited to 6 months from date of purchase

Please note that ElectronCycles no longer have any association with ERT

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