Electric chopper trike build journal

Parking Brakes - Part 2

The stop is positioned and then welded to the brake lever mounting bar.



Photo below shows the brake lever bolted to the mounting bar and the ratchet stop (red arrow)



Photo below shows the entire brake lever mechanism and stop bolted onto the trike’s frame. The red arrow shows the ratchet stop.



Photo below shows the brake lever in the released position. In this position it will be tucked under the “dash” of the trike and partially hidden from view once the dash is installed.



The final Photo shows the brake lever in the engaged position. When engaged the level protrudes out from under the dash and will be easy to spot to remind the rider to release before engaging the motor.

Variable Regeneration Controls - Part 1

My Kelly KLS7230S controllers are capable of providing variable regeneration. To alter the amount of regeneration the controllers need a 0-5 volt signal. The simplest way to provide that variable signal would be with a common twist or thumb throttle located on the handlebars. But I felt a second twist throttle, or even a thumb throttle would be confusing and sort of counter intuitive. I felt a better solution might be to mount a typical brake lever on left side handlebar and then run its cable to a thumb throttle mechanism located toward the rear of the trike. My thinking is that this will provide the more natural “feel” of a traditional motorcycle hand brake when the regen is activated.


Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.


To do this I am using a freewheel body from an old six speed cassette stack. Note that the freewheel body has two grooves (arrows), one larger than the other. By running the incoming brake lever cable around the smaller diameter groove and the outgoing thumb throttle cable around the larger groove, the pull of the brake lever can be multiplied enough to move the thumb throttle lever from its zero position to its 5 volt (maximum) position. The six speed freewheel body is threaded onto the wheel hub allowing it to freely rotate while still being held in the proper position.



Only the threaded “cassette” side of the wheel hub is needed, so the balance of the hub is cut off leaving the hub disk and threads as a mounting platform for the freewheel body.



The hub disk is ground flat on the back side.



To guide the cable from the brake lever onto the groove of the free wheel, an old brake lever handle is cut apart saving the guide (arrow) and a portion of the lever which is drilled for mounting bolts. A stock brake lever is shown on the right and the cut down portion use for the guide is shown on the left.



With the freewheel body unscrewed and removed we can see the threaded mount of the hub disk. Two 1/4″ holes (arrows) are drilled in the hub disk for mounting.



The components are laid out on 3/16 x 3″ wide flat stock. On the left is the “guide”, in the middle is the freewheel body “gear multiplier” and on the right is the thumb throttle. (Photo 6) When everything appears to be in alignment for smooth operation, the mounting points for each component are marked and the flat stock can be cut to the appropriate length and appropriate holes drilled for mounting the guide and the hub disk. The thumb throttle is mounted on a short length of handlebar tubing which is welded to the 3″ flat stock.



The components attached to the base. The thumb pad of the throttle will have a small hole drilled through the center for inserting the cable.



To secure the end of each cable in the freewheel body groove a “bridge” is welded over the top of each groove. The cable is then inserted into the groove and under the bridge. To insure the weld does not go all the way to the base of the groove, making it impossible to fit the cable under it, a large diameter copper wire is placed in the groove while the bridge is tacked in place. The copper will not bind to the weld and can be pulled out once the weld has cooled. The cable can then be threaded under the bridge, tightened and a stop crimped to the cable. [Note: Variable Regen continued in next post.]

Variable Regeneration Controls - Part 2

Note that the cable from the brake lever to the freewheel body “gear” needs to be adjustable in order to get the cable tight. Instead of crimping on the stop, a cable ferrule is used and a small screw inserted into the open end of the ferrule and tightened securely. Not a particularly elegant solution, but it works and the cable can be readjusted at any time.



The thumb throttle has its own spring to return it to the zero position but to insure the throttle does not hang up due to friction in the cable or gear mechanism, an additional spring (arrow) is attached to the back side of the throttle lever.



The variable regen mechanism is then bolted to the trike frame. With the cables attached the left hand brake lever now operates the thumb throttle which, in turn, engages the regeneration function of the two Kelly controllers on a variable basis. The harder you squeeze the brake lever, the greater the amount of regeneration AND the greater the amount of braking effect created by the regeneration.

cboy said:

Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.

Click to expand...

If you like, ProblemSolvers makes a small pulley to fix this kind of issue with brakes, that would also probably work for your situation, called a Travel Agent
https://problemsolversbike.com/products/brakes/travel_agents_-_6416
and theres a page here that has an install / adjustment guide
https://www.parktool.com/blog/repair-help/travel-agent-installation-and-adjustment

Itd be smaller and lighter most likely than the freewheel/hub body.


That said, I like the work you did to solve the issue your own way.

amberwolf said:

cboy said:

Unfortunately, the “throw” of most brake levers is not quite long enough for the cable to pull the thumb throttle from the zero position to the full throttle position. As a result, the controllers would not receive a signal for maximum regeneration. To remedy this situation I needed a way to “gear up” the cable so the brake lever movement can provide a longer pull.

Click to expand...

If you like, ProblemSolvers makes a small pulley to fix this kind of issue with brakes, that would also probably work for your situation, called a Travel Agent...

Click to expand...

My "default" solution is usually to look around the shop and see what piece of old junk might work to solve a problem. But thanks for the link etc, it provides another good option for folks to consider. I also received another possible alternative, using a small lever with an offset fulcrum to multiply the throw distance. So lots of ways to skin this cat.

Nice project!

Can hall throttle be used on Kelly controller?

If yes, there is also the option to disassemble hall throttle and stick the linear hall sensor to brake lever base and magnet to the lever.

parabellum said:

Can hall throttle be used on Kelly controller?

Click to expand...

The Kelly controller can utilize standard throttle input from 0-5 volt 3 wire resistive pot or from 1-4V hall active throttle according to the specs in the user manual.

Good for Kelly, old types only did 0-5V.
Is the V range adjustable for variable regen?

parabellum said:

Good for Kelly, old types only did 0-5V.
Is the V range adjustable for variable regen?

Click to expand...

The throttle input is adjustable for range and can be programmed into the controller. But I don't believe the variable regen input is adjustable, at least I couldn't find anything in the setup info to do that. That's why I went with "gearing up" the cable. The build is not quite to the point of actually doing the programming yet so I might discover something when I hook up my PC to the controller and start snooping around.

Plywood Core Body Panels - Part 1

To protect the electrical components and wiring for the trike, body panels will be made to enclose the battery and electronics compartment. A body panel will also be created to serve as a “dashboard” for mounting switches and to enclose wiring at the front of the trike. The body panels will be made using lightweight and relatively inexpensive aluminum flashing. Used alone, flashing is too thin and would reveal bumps, bows and other distortions in the metal. So I am using a technique I have used to make dashboards and other panels for some of the hot rods I have built. Each panel has a “core” made from 1/8″ plywood. The aluminum flashing is then cut and glued to the core to form a solid, stable surface. Note that this technique can only be used on flat surfaces or surfaces curved in only one direction. It can not be used for compound curves or compound/complex curves.

Each panel section core is measured and then cut from 1/8″ plywood. Photo below shows all the plywood panel cores for the chopper trike.



Aluminum flashing is cut to the outer shape of each panel with ½” to 5/8″ of extra material on all edges. Do not cut out irregular shapes of the panel at this point.



Apply DAP Weldwood contact cement to the front of the plywood and the rear of the aluminum. Dry for the recommended time period and attach the aluminum panel to the plywood panel making sure to leave ½” of flashing extending beyond the plywood on all edges.



From the plywood side, a simple panel will look something like the Photo below. Note that none of the irregular shapes have been cut out at this point.



On the flashing side the panel will look like the Photo below.



Using a good set of tin snips or metal cutting shears cut each outside corner as shown in Photo below.



Inside corners are cut as shown in the Photo below. Once all corners have been cut, apply contact cement to the exposed surfaces and to the back side of the plywood, wait the appropriate time, and then fold the edges of the flashing over the edges of the plywood and press firmly in place on the back side of the plywood.



The finished panel should look something like this.

Plywood Core Body Panels - Part 2

This Photo shows all of the completed plywood core body panels for the chopper trike.



The “dashboard” panel is installed with machine screws for easy removal.



The other body panels are attached using nylon push type fender rivets. These rivets are most commonly found in automotive application for both interior and exterior fastening. The rivets can be removed once they are in place but they do sometimes break off or become difficult to remove. So if you know a body panel is going to be on and off a number of times it might be better to use a different type of fastener, such as a machine screw. Also, some may want to choose a different fastener if the do not like the “look” of the nylon rivets.



Photo below is a close up of an installed fender rivet.



The top panels of the battery box lid are riveted in place.



Access holes for electrical wiring are cut in the body panels with a hole saw.



Rubber grommets are used to enclose the holes and protect the wiring.



The front view of the completed body panels. Note that the two openings at the upper left and upper right of the deck lid are purposely left uncovered to allow air flow to help cool the controllers and the battery box.



The completed battery and electronics compartment from the rear.

I'm wondering how far this build has come up till now? Any progress you can update us with? Or are you already riding around on this trike?

SlowCo said:

I'm wondering how far this build has come up till now? Any progress you can update us with? Or are you already riding around on this trike?

Click to expand...

Not quite riding yet. Progress has slowed because we (a group of volunteers from our church) also build adaptive bikes/trikes for special needs students in my shop and we had a flurry of orders as the school year was winding down. So those bikes are always a priority. But I'm back working on the chopper trike now getting the electrical systems sorted out. Should have some photo updates shortly.

Great to hear you're still going and thumps up for delaying the build for such a good cause. Good luck with the electrical system and hope to see progress pics soon. Some photo's of the adaptive bikes and trikes are also welcome to share of course.

It looks like you've largely sorted it out already, but an idea I wanted to throw out there (since it's what I'm doing on my motorcycle) is to grab a cable throttle body complete with the rotor and throttle position sensor (TPS) from a junkyard. I like how the stock throttle on my Ninja 500 donor bike feels a lot more than I like most electronic throttle options, and it seems like a good alternative to buying a (usually expensive) throttle potentiometer setup, or spending an afternoon setting on up myself.



You've got a rock solid aluminum assembly that's reasonably compact, with a flat mounting surface and a generally-square bolt pattern. The throttle rotor is already set up to connect to a cable, and the TPS is almost always a 0-5v 3-wire sensor (5v, sensor output, and ground). At least for the honda's I learned on, all of the above applies and they basically never break. If a TPS gets replaced, it's usually because something physically smashed it.

Grab one of those off pretty much any 1990's civic or accord, bolt it down, run a cable to it and you're good. Then take a cutoff wheel to remove all the crap you don't need/want, like the throttle blade, most of the throttle tube, any kind of idle air control, intake pressure sensor, etc.

phate said:

... grab a cable throttle body complete with the rotor and throttle position sensor (TPS) from a junkyard. I like how the stock throttle on my Ninja 500 donor bike feels a lot more than I like most electronic throttle options, and it seems like a good alternative to buying a (usually expensive) throttle potentiometer setup, or spending an afternoon setting on up myself...

Click to expand...

Gotta love the ingenuity of this alternative. Thanks for posting it up phate.

cboy said:

phate said:

... grab a cable throttle body complete with the rotor and throttle position sensor (TPS) from a junkyard. I like how the stock throttle on my Ninja 500 donor bike feels a lot more than I like most electronic throttle options, and it seems like a good alternative to buying a (usually expensive) throttle potentiometer setup, or spending an afternoon setting on up myself...

Click to expand...

Gotta love the ingenuity of this alternative. Thanks for posting it up phate.

Click to expand...

No problem. I'm just getting into EV's after I saw what could be done with the cheap brushless/lipo combos that are now widely available for RC cars, but before that I messed around with old honda's, and have used potentiometers to fool the ECU into thinking a 5v sensor exists. More specifically, after I converted my 97 accord from an automatic to manual, and the replacement ECU was looking for a few sensors that didn't exist on my car.

Note: I haven't actually gotten either of my Kelly controllers (KLS7230s's just like yours) to talk to a honda TPS yet, but a 5v signal is a 5v signal is a 5v signal. Shouldn't weigh too much after you cut everything off it, either.

EV West and a few other companies make some very nice machined aluminum potentiometer throttle assemblies, and I would absolutely run one of those if I was building something for a customer, but for my purposes I'd rather just use something ready made.

Additional note: When wiring the controllers, don't do what I did and mix up the thin pink wire (controller power on) and the thin red wire (controller 12v output). They can look awfully similar under a work light, but things go "bang" and stop working if you do. I just got my replacement controller, and I'm hoping to open that up and match the scorch mark in the old one to a component in the blown up one.

SlowCo said:

Some photo's of the adaptive bikes and trikes are also welcome to share...

Click to expand...

Always glad to share the results of our adaptive bike program. These will give you an idea of the types and styles of adaptive bikes we build. All of our bikes are "cobbled together" using parts and pieces from clunker bikes donated to the program. We cut up the bikes to recover their essential components and we then design and fabricate frames specifically designed for the needs of each student. Bikes are donated from a variety of sources but the majority come via Waste Management Corp (our area garbage and recycling service) which allows us to recover bikes which would otherwise go to the crusher. Another partner in the programs is the Merced County School District and staff members who identify and refer the students for the program. The program is funded by Shepherd of the Valley Lutheran Church (in Merced, CA) and by the Merced Sunrise Rotary Club. Once finished, the bikes are provided free of charge to each student. Most of our adaptive bikes are three wheelers although we occasionally build a two wheeler and we are currently designing a tandem bike for a blind rider and a sighted rider to ride together.

Tadpole style. We sometimes use this style for students who are able to pedal, steer and brake but have difficulty with balance or other issues.





Rear Push and Steer. This design is for students who are unable to pedal, steer or brake on their own. An adult pushes from behind and steers remotely from behind. The student learns to pedal and increase leg strength until they can pedal and/or steer on their own.





Rear Push and Steer with tiller and major torso support. A more complicated rear steer design which keeps the steering linkage out of the way, often required for larger students. The seat design is for students requiring maximum trunk or head and neck support. We design, make and upholster our own adaptive seats and supports.





Another Rear Push and Steer. This is design for larger and taller students.





Electric Assist for Heavyweight Rider. We had to rebuild this bike three times to get it right. An extra wide power bracket and pedal axle was required as well as an extended heavy duty frame and a 1,000 Watt hub motor. The seats we built simply couldn't handle the forces of a 400 lb rider. This garden tractor seat finally did the trick.



You can read a bit more about the Adaptive Bicycle Ministry and find links to Instructables for a few of the bikes by going to my website and scrolling down to the Adaptive Bike link.

What a great job you and your fellow volunteers do for these people!
Glad I asked. It must be very fulfilling to be able to built bikes like that and help someone with it. Two thumps up from me!
Keep up that great work and I hope to see the progress on your own trike soon.
Warm regards,
SlowCo

High Voltage Electrical System - Part 1

After a bit of a delay the chopper trike is once again moving along.
The trike will have a 72 Volt (high voltage) wiring system for powering the rear wheels and a 12 Volt (low voltage) wiring system for the peripherals such as headlight, tail lights, turn signals, horn etc. In some instances these two system overlap which will be shown in the progress photos.
The High Voltage system is powered by six 12 volt deep cycle batteries. The batteries and other high voltage components are wired using 4 awg extra flexible welding cable (all cable and wire sizes are based on recommendations from Kelly Controllers and QS Motors) with 4 awg 3/8″ tubular lug rings.



A Forney lug crimping tool is used to crimp the lugs to the cable ends.



A couple completed cables.



I’ve learned from my smaller electric trike builds that my fumble fingered habits can result in some pretty nasty sparks and blown fuses when a tool or other metal object happens to fall into a battery array and Murphy’s Law asserts itself. To help reduce the chances of accidental shorting across battery terminals “Oops Stoppers” (safety covers) are made from cheap and abundant plastic milk jugs.



The cartons are cut into sections wide enough to cover each battery terminal and its adjoining threaded stud. Two holes are punched out of the plastic so that it fits over the terminal and stud. I used upholstery punches to make the holes nice and round but it could be done with a drill, scissors or exacto knife. The milk carton material can be folded over and pressed by hand to form a “flap” over the top of each lug.



The safety covers are placed over the terminal and stud and then the battery cable is bolted onto the stud when holds the oops stopper in place.



The battery array with all of the safety covers in place. These protectors don’t guarantee the elimination of accidents, but they are a cheap and easy preventative measure.



To further help prevent shorting in the battery pack and to provide a non-conductive mounting surface for the major electrical components, a sheet of acrylic plexiglass is mounted over the batteries. The plexiglass is visible as the slightly cloudy surface between the controllers in Photo below.

High Voltage Electrical System - Part 2


A major safety requirement for any higher voltage electric vehicle is an emergency shut off which is built specifically not to arc and create a major melt down when the battery pack needs to be totally disconnected from the rest of the electrical system. A Holdwell ED250B-1 “Big Red Button” is used for this purpose. The button will be mounted below and just to the right of the rider on the main frame rail and within easy reach. This is also a fairly visible position for emergency crews to find the shut off. A bracket is made from 3/16 flat stock so that the body of the shut off will be surrounded on three sides.



The mounting box is welded in place on the frame and the big red button is installed. The positive cable from the battery array runs directly to the emergency shut off and from the emergency shut off to the contactor.



A mounting block for the shunt is made by epoxying together plexiglass sections. This allows the shunt and connectors to be isolated and protected from shorting out on anything metal.



Connection terminals for the main wiring from each hub wheel to each controller are fabricated from sections of plexiglass epoxied and screwed together. Each wheel and each controller has three phase wires which will be connected on this terminal block. Each controller will also have a plus and a minus high voltage wire which connect at the terminal block to the plus and minus wires from the battery pack. After these photos were taken, screws were added to the terminal blocks to ensure the epoxy joints remained secure.



Photo below shows the connections made on the terminal block.



The high voltage components installed on the plexiglass mounting panel and wired up.

Regen Controller - Redux


With the 72 volt wiring completed a computer can be connected to the controllers to do some initial programming and to monitor various functions to determine if all the wiring thus far is correct. The monitoring process led to the discovery that my regen throttle controller (see Regen Controller section) was not able to fully engage the thumb throttle and as a result the regeneration was well below full capacity. The regen controller “worked” in the sense that it did, in fact, engage the regen function, it just didn’t move the throttle far enough to reach full regen capacity. Even with various adjustments to the mechanism I was only able to achieve a little more than half the voltage needed to fully engage regeneration.


So the mechanism was dismantled and, as suggested by some helpful readers of this build journal, a simple lever system was created. Fortunately I was able to use the base plate, cable guide and thumb throttle mounting stub from the original design.


The lever is a 4″ long section of ½” wide 1/8″ flat stock. The bottom hole will be the pivot point. The next hole, 1″ up from the pivot, will be used to bolt on the cable from the brake lever. The top hole, 3″ above the pivot, will be used to bolt on the cable to the thumb throttle. (Photo below) This layout provides a 3:1 ratio. In theory, the 5/8″ of “pull” provided by the brake lever will move the thumb throttle 1 7/8″. In reality, due to slop in the system and minor errors in measurements, the ratio turned out to be slightly less but it was more than enough to move the thumb throttle it’s full 1 ½” travel distance from 0 throttle to full throttle.



A 1/4″ nut is welded to the pivot hole of the lever. Take care not to get any slag on the threads of the nut.



A 1/4″ bolt and “lock nut” are tightened securely to the mounting plate and the nut and lever combination is threaded onto this mounting bolt. The lever nut is threaded just far enough so that it is secure but still rotates freely without becoming tight against the lock nut. This basically functions as a poor man’s heim joint. The lever easily rotates back and forth while remaining stable and secure on its pivot point.



The cable guide from my original controller is bolted to the mounting plate so that the cable will line up directly with the lower bolt. The guide was originally part of a discarded hand brake lever. The upper and lower cable bolts on the lever will have small holes drilled through them so that the cables can be inserted in the holes and tightened. The Photo below shows the lever position when the thumb throttle would be at rest.



The next Photo shows the lever position when the thumb throttle would be in the wide open position.



The completed mechanism with the thumb throttle, cable guide and lever installed is shown below. Testing with the controller software program indicates this simple lever design is able to provide full throttle power to the controllers and will provide full regeneration capacity. It also pulls easily with the hand brake lever. So thanks to those who provided me with alternative suggestions for the regen mechanism. This design works far better than the earlier version.

12 Volt Electrical System


Switches for the 12 volt appliances are installed on the “dashboard” panel. The rectangular switch with the small blue lens at the top of the array is a three way switch which “shifts the gears” selecting either forward, neutral or reverse on the controllers. The four round switches are used to turn on the DC/DC converter, to turn on the 12 volt system itself, to control the daytime running lights (headlight and a tail light) and to control nighttime running lights. I separated the daytime (required by law) running lights from the nighttime running lights to conserve a bit of energy during daytime ridding. I also isolated the dc converter and the 12 volt system on separate switches so that work can be done on the 72 volt system without having power in the 12 volt wiring. This is just a personal preventative measure based on my tendency to insert metal tipped tools and my fingers where they don't belong.



The round switches have small LED lights which indicate when the switch is in the ON position. Each switch LED is a different color to assist during night driving.



A view of the switches and wiring from under the dash. Unfortunately, neat and tidy are not among my skill set. This is actually an improvement over the initial wiring which I redid after everything functioned properly.



Relays for the turn signals, headlight and running lights are also located under the dash board. It would appear from this photo that the emergency brake cable might interfere with a couple wires. In reality, when the cable is pulled taut and the wiring bundled with a cable tie, everything operates without coming in contact.



At the rear of the bike, from bottom to top, are a set of turn signals, a center array which includes the license plate light, brake lights, daytime tail lights and turn signals. Above the center array, in the lower section of the cargo case are the night time tail lights and day/night brake lights. Not shown in the photo are side markers on each side of the cargo case.




At the front of the bike is the headlight which includes hi and low beams along with internal amber turn signals. To the left and right of the headlight are external turn signals (the pointy arrow like things). These turn signals are nifty because they are on a flexible, spring-like base. If someone inadvertently hits or brushes against them, they flex and then snap right back into position.



Also at the front of the bike is my poor man’s “turn signal cancellation unit”. I have turn signals on my 1,000 watt recumbent and I am forever forgetting to turn them off after making a turn. So on this bike I have mounted turn signals on the handlebars which point rearward rather than forward…right at eye level with the rider. Not only will these turn signals remind me to cancel the unit, they will actually provide a bit more notification of my turn to anyone traveling behind me, particularly at night. Also in this photo is the center mounted Cycle Analyst 3 which provides a wealth of information regarding the electrical system along with controlling many functions such as the throttle, e-brake cut off, cruise control and high temperature safety shut offs. It also provides a speedometer, odometer and keeps data for each "trip" as well as cumulative data on energy usage and regeneration.



I used the Kawasaki donor bike handlebar module for control of the horn, headlight dimmer and turn signals.



The “magic box” now containing the 12 volt system wiring along with the 72 volt wiring. Note that a 12 volt battery is installed as well as a dc/dc converter to provide power to the 12 volt system. Once the bike and electrical systems have been fully road tested, I may remove the auxiliary battery and run only off the converter.

Just a quick update for those following this build thread. Shake down testing of the finished trike revealed a major problem. Under acceleration the trike pulled hard to the left. If you are a gluten for punishment you can read through the very long troubleshooting and hair pulling process here.

The good news is, after a couple weeks of thrashing, Kelly Controllers came to the rescue and provided me with software to configure the controllers into "pure current mode" (aka torque mode) rather than the "speed mode" which is how they come from the factory. The programming fix worked wonders and the trike is now going straight and true even under heavy acceleration. So I've finally been able to log a few miles of enjoyable riding. I hope to have some finished photos and possibly some video in the next couple days.

One final note regarding the controller fix. It seems there is some confusion about the KLS-S series of Kelly controllers. Some are under the impression they are "torque mode" or that the user software that comes with the controller allows a choice of "speed", "torque" or "balanced" modes. This is not the case. These controllers come from the factory as "speed mode" and can not be switched with the user software. HOWEVER, if you are purchasing the controller from Kelly (which I did not...I bought mine through another vendor) they can re-program it at the factory, prior to delivery, so that it arrives in torque mode. I would highly recommend that change for anyone building a dual motor EV. Kelly Controllers was very gracious in writing up a bit of firmware for me so that I could re-flash my controllers even though I had not purchased my controllers directly from them. But it would be far easier, and a lot less headache, if I had know ahead of time, to have had these controllers programmed at the factory for torque mode. If you have a single motor vehicle, this is not an issue. But a dual motor vehicle can get very unruly if torque is not balanced at the wheels.

FWIW, based on my recent experience testing the SFOC5, a torque or current controlling throttle is generally a lot easier to control even a single-motor system, especially anything higher power than a typical "low power" ebike.

So I'd recommend that type of control on almost anything using these controllers.