Kill Yourself 50% Faster With 2x The Power: E.R.T.’s 72v 50Amp 3000W Ext BBSHD Controller

It’s finally happened, Alan from Electric Race Technologies is marketing a 3000W external controller to pair with the BBSHD to allow you to run 50 amps and/or 72v through your stock BBSHD for $159.95 right here. I hooked up a 65Amp Lyen controller to my BBSHD (and promptly melted the nylon gear) about a year ago, but the BBSHD now seems to be able to run pretty well at 50 Amps without getting destroyed. I’ve been testing the BBSHD for hundreds of hours on a 52v 50Amp Ludicrous controller on the street and in the woods and I can say that I have had zero drive issues with this setup. The BBSHD motor was designed to run at over 2500W peak, there is no question in my mind. I believe that Bafang massively overbuilt this motor so they could release more powerful versions over time when the 30 Amp version has proved itself. What has happened is that people are just refusing to wait for Bafang to do that and are working out their own solutions on how to pump more power into the drive themselves.

The ERT custom 72v 50Amp controller (top right) shown with the old BBSHD controller used as a cover

The ERT custom 72v 50Amp controller (top right) shown with the old BBSHD controller cleaned out and used as a very nice wire cover

The stock 30Amp BBSHD goes over 30 mph without any issues, but if you want to get it to go over 40 mph then you will probably need to mount the stock BBSHD on a skinny tired road bike (super scary) or get a more powerful controller. I don’t really recommend going 40mph on an ebike for any length of time because frankly it’s pretty dangerous (not to mention totally illegal). That being said the rule of thumb is if you want more power add more amps, if you want more speed then add more volts. This controller will allow you to do either or both. The ERT controller has a High Voltage Cutoff of 100v meaning you can run it at 88v (insane) for the ultimate in high speeds. I’m told that the ERT controller can also do 60Amps, although it is still advertised as a 50 Amp controller.

The CA3 gives you the ability to do Temp Sensing and ramp down as well as PAS

The CA3 gives you the ability to do Temp Sensing and ramp down as well as PAS

For an extra $150 option you can add a Cycle Analyst v3 to your controller which will allow you to set up the PAS system as well as thermal sensing on the BBSHD. At 3000W I would not plan to run the motor continuously at the highest power level, it will heat up and stuff will stop working.

To be clear I have not purchased this item and tested it (I hate writing articles without testing stuff) but for people who want to upgrade their BBSHD’s this is an option that has not been available commercially yet so I felt like it was important to get the information out there and let the readers decide if they want to go for it.


  • You can add it to any BBSHD drive unit without having to buy a whole ebike to get the Ludicrous controller
  • It’s $100 cheaper than the 50Amp Ludicrous controller option (without the CA)
  • You can do thermal sensing & PAS with the CA3 ($150 extra)
  • Allows you to pump 3000 tire shredding watts through your poor drivetrain
  • If you don’t like the controller you can easily switch your BBSHD back to the stock controller
  • You can use the existing Temp Probe in the BBSHD and existing PAS sensor inside the drive unit
  • Can run a 72v or a 88v battery with the BBSHD, no problem


  • You will have to silicone the connectors to keep water from getting into the drive unit
  • It’s a large, heavy controller that is going to ugly up your ebike and has to get mounted somewhere air can flow over it for cooling
  • You have to program the controller if you want to change the settings (unless you have a CA3)
  • 3000 Watts is going to probably make stuff fail pretty fast on your ebike drivetrain or at least stretch your chain awfully quickly
  • There is a good chance you will smoke your nylon gear or windings if you run this baby at 3000W for any real length of time
  • It’s going to be a pain to wire to the existing PAS and thermal sensors inside the drive unit (read ‘not for beginners’)
  • A smaller chainring is going to be necessary for higher power on the drive unit (30T Luna Mighty Mini shown in picture) if you don’t want to shred the internal gears

The primary difference between the 50 Amp Ludicrous controller is that the Ludicrous controller mounts onto the BBSHD directly and although the cooling fins are larger than the stock one, the shape is mostly the same. The ERT controller looks like a standard ebike controller and would be mounted on the frame (probably on the underside of the the downtube) and is wired into the BBSHD directly. You will need to waterproof the connectors using silicone and heat shrink the phase wires on the ERT controller. The other main difference is that Luna is only selling the Ludicrous controller when you buy one of their bikes and does not sell them separately to the public. The Luna Ludicrous controller has a HVC of 60v meaning you can only use a 52v pack on it, but the ERT controller has the capability to use a 72v or even a 88v pack which should make the BBSHD have a much faster top speed.

I’m anxious to see how the BBSHD performs with a 72v pack, as the 3000W Cyclone system is worlds better than running it at 52v (as shown when I tested Curt’s Luna custom cargo bike). If it were me I’d make a choice to run the BBSHD at either 50 amps if you want more power or at 72v if you want higher top speeds, but I probably wouldn’t do both. If I did do both I would be pretty careful not to thrash on the throttle too hard as you’re putting over 3000W intro a drive unit designed to run nominally at 1000W.

You can also run the BBSHD with the Grin Tech Phaserunner 50Amp controller as seen in this picture

You can also run the BBSHD with the Grin Tech Phaserunner 50Amp controller as seen in this picture which I’m told is also pretty awesome

The good news is that you can take any high power ebike controller and hook it up to the BBSHD if you can get the hall sensor wires run correctly. When I did my testing I just grabbed a controller off my ebike parts shelf and promptly burned out my plastic gears. There is a lot of fancy settings with these ebike controllers that I have absolutely no understanding of, so there is a chance that using any old controller off the shelf is going to have problems with the BBSHD motor. This ERT controller is the first external high voltage controller I’ve seen advertised for the BBSHD. With a full 30 day warranty (controller only, not the BBSHD), and at just $159 I’m sure there is a market out there for it.

If you’ve tested the BBSHD at 72v (or higher) and like the way it performs, please leave a comment below so we can all learn from your insight.

Ride On.

21 thoughts on “Kill Yourself 50% Faster With 2x The Power: E.R.T.’s 72v 50Amp 3000W Ext BBSHD Controller

  1. Funny you mention Alan – I was just singing his praises on Reddit amidst a gaggle of Debbie-Downers and industry old-boys. (Copied below.)

    I purchased his sinewave external controller (the one mentioned here) a couple weeks ago, and can’t wait to play with it. Most people won’t want to mess with the work and soldering required, and the crappy looks, of adding an external controller. But right now, it (and his other controller – Grin Phaserunner) is the only way outside Luna Ludicrous to get 2500+W from a BBSHD.

    I think that along with Eric Hicks, Alan is THE innovator in this field right now. Without the two of them, the high-performance e-bike industry would be nowhere near where it is now.

    My Reddit post:

    I want to add something – I think Alan is the pioneer in the field of pushing the BBSHD to its limits and seeing exactly where the breaking point is.

    Nobody besides him has experimented so much with different configurations of external controllers, batteries, and voltage to see exactly what the ‘HD can take. And amazingly, even pumping 96v and crazy amps (running at well over 3000w total) into the poor thing, it hasn’t broken yet (to my knowledge).

    I applaud him for his efforts in pushing the envelope of high performance and seeing just what is possible with this motor (and others). I purchased a controller set from him and can’t wait to start experimenting with it. I hope that he comes out with an integrated solution soon (replacing the stock controller housing on the motor, not an external controller), that would be a game changer. Of course, the Luna 2500w Ludicrous already offers this but is currently limited to 52v, and sold only with complete bikes.

    Yes, I agree that high-speed testing should be done on closed courses, not on public roads. And pushing any e-bike (road, mountain, or fatbike) well above 40mph is dangerous and way above the spec limits for tires, brakes, etc. But to chastise him for this action, while ignoring the other advances he has made for the high-performance industry, is really mypotic.

    Alan, keep up the great work!!! Waiting for that integrated Grin PhaseRunner! 🙂


    • I think it’s good for Eric to have some competition, keeps him on his toes. I know Eric is working on a 72v integrated BBSHD controller, but it’s not to market yet. It’s also unlikely that you’ll be able to get one unless you buy a whole bike which has frustrated a lot of the DIY crowd.


    • I was in that Reddit thread.

      The “Debbie-Downers” you speak of were negatively commenting on him blasting around, doing 65mph on public streets in traffic…not his build. Most still said it was awesome, just not when it’s breaking speed limits on Main Street with no indicators and insurance. Which is %100 fair.

      If you’re gonna tell a story, tell the whole story.

      And I agree it’s a totally wicked bike. 🙂


  2. Ok, i finally got my old Brompton powered up with a Grin front hub and a 3 lb 7ah magic cube. Runs fine.

    Now i want more speed and more plush. No hilly trails or snow around here but the potholes have potholes.

    I,m thinking full suspension, semi fat tire, bbshd. Possibly a folder.
    I’ll go cheap except for the Bafang.

    Suggestions appreciated



  3. Hello.

    I have 3 reasons why I wont recommend HD on 3000W:

    1. Everything over 2000W would break standard chain and also deraileur will suffer. (I have 1600W and broke 2 chains apart on start)

    2. Nylon gear wont handle it for long.

    3. You need stiff frame. It bands my frame as a bow a lot. It does easily 3 to 5cm sideway, even you feel it under your feet.
    I would reccomed hard downhill frame for 3kW. I have this frame

    HD is overall a nice motor, just a little bit heavy.


  4. I love this because it’s too much for most people. I love it because it gives me the choice of running low power or pinning the throttle and going WFO just because I feel like it. I love it because it’s something you would never see on a production ebike…. Awesome.


  5. I have almost completed a build for Luna forum member CraigAustin using this setup so I have a couple of points. First, YES, it will break chains and mangle cassettes. I broke the chain once at 35mph, pinned the throttle, the front end came up, and then the chain broke! REAL POWER! But it can be tamed with the Cycle Analyst and a Gear Sensor. Second, this is NOT a build for the unskilled! If you are not comfortable with soldering at 2mm spacing, and do not possess a thorough understanding of how BLDC motors operate, as well as being comfortable programming the setup, (which is more art than procedure), I wouldn’t suggest you attempt it. However, if you are so blessed, what are you waiting for?! This thing IS an animal! no doubt about it! But I love animals! Especially the dangerous ones!


    • Great to hear the feedback! What voltage/Ah/BMS battery pack are you using with it?

      Which part of the install required the 2mm soldering precision? From my understanding (and Alan’s brief instructions), after removal of stock unit, it’s basically re-connecting the phase wires to the Controller phases (I was planning on putting in new Anderson connectors), then plugging in the small connectors (hall, CA) to the motor.

      Are you referring to difficulty in mounting the temp sensor?


      • It’s running a 72v 20Ah 50A BMS Pack.
        Installation is as Alan describes, but only if you run all throttle all the time. The temp sensor is already in the motor, you just hook up to the pig tail Alan left on the Hall sensor plug. The problem is, the CA only supplies 15ma of current to ALL 5v circuits! And that at 48v battery power, and as Ohm’s law say’s, Voltage up=current down, so with a fresh 72v batt, at 84v, you have <10ma of current to run-PAS, Pot and throttle or you may damage the CA. This is the one of two design flaws I have found with the Cycle Analyst, the other is the wiring cluge in back! Other than those two things, I think the CA is the best display made, hands down! In fact, I will never do a build without one, they provide so much control and info! Just integrating the CA to a stock BBSHD would be a huge improvement over the almost worthless DPC14. Color be damned! I need real accurate info! Not what PAS level I'm in in three colors! To be fair, it does have a fairly accurate clock!
        Anyway, to get around the shortfall of 5v supply, you will have to build an auxiliary 5v supply, open the CA Analyst, and tie it in. At the same time you can eliminate some of the wiring cluge by shortening things up you need and getting rid of those you do not in the CA. The CA uses 2mm spacing on it's solder pads. It's not difficult at all, just gotta be REAL careful!


  6. Thanks for the information and sharing your experience installing this, Rick! Totally agree that the CA3 is the best thing on the market for providing tons of information, and config flexibility. Even if it looks like it came right out of 1986! 🙂

    You’ll be running that at up to 3500w – please provide an update after your client has some miles on it, to see how reliable it has been. Would love to see a chromoly replacement gear available to replace the stock nylon one as well (silence be damned!).

    Didn’t know about the 5v limitation of the CA3 – don’t plan on using PAS for this build but good info nonetheless. Will report back when mine is done; after I get my 72v pack from Luna!


    • I have done a couple of ‘temp test runs’ to try and over heat the motor to the point of thermal roll back. On an 85 degree day, after making two 2 mile WOT runs, Motor temp only came up to 62C. about 145F, barely getting warmed up! My thermal rollback is set for 130C, about 265F, I never did get it to hit thermal roll back, even after 8 runs, 7 really, the 8th was real weak, seems WOT drains batteries pretty quick! Temp never exceeded 110C. Going to try it with longer runs, say, 5 miles see how it does. All testing was on level ground with 30 seconds break between runs. I also re greased the infamous nylon gear, but I do not use Mobil 28, I use Lucas Oil Red & Tacky #2. Similar to Mobil 28, but superior IMHO. Alan’s motor on the videos sounds wicked, but mine, even at WOT is silent as the stock motor. I think he had the microphone real close to the motor to show people how it sounds. You definitely hear the higher rpm’s, but not at an increased level.
      Longevity is the real question. If it won’t last than it only has limited use potential. (racing) But I have high hopes for it! It is not going to be used as a racing bike, but as a commuter. So while it will be capable of 50mph when complete, it will typically be used in the 20-25mph range much like a stock BBSHD. But when Craig needs to climb the big hill on the way to his office, he can hit the throttle and climb it at 35mph just like the cars, which makes it way safer than going up it at 15mph with the stock BBSHD, and cars on your a$$ blowing the horn and trying to pass in a place where it is unsafe to do so. Speed can kill, but used wisely it can save your a$$!


  7. Nice to have options! There will be a huge demand on these things when your average Joe figures out what they do. Would prefer stealthier Luna version if I had the choice.


  8. If one could only make the Grin Phaserunner fit inside the empty BBSHD controller enclosure!! The only downside to the BBSHD i can see, is the gearing. It should have a max pedal cadence of 100-120rpm at full motor speed. And a ISIS crank..


    • I’ve been saying this for weeks. I proposed to Alan from ERT that he work with grin to design an integrated PhaseRunner that fits in place of the stock BBSHD controller.

      They would sell a BOATLOAD of ’em. Too bad they haven’t done it yet.


  9. Thanks Karl for your articles.
    The Grin Phase Runner combined with the BBSHD is looking promising. The Phase Runner may not fit inside the original controller housing but at least it is compact. Reading the thread over at endless sphere it looks like they can be problematic to program though.


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