Motor cable question (front hub)

[SnowFox102]

Hello all, new here and I apologize if this is in the wrong place but I wasn't sure where to put it! Tl;dr, what's up with this flat black connector? All the motor cables I'm seeing for sale have the six wires in two rows, this one has them in one row. Am I stuck having to solder a new connector?



The full story: I have some experience with ebikes, but it's limited to a pair of Jetsons so that barely counts. My current love is a trike, a Soumye 186. I went with off the shelf for various reasons, one of which being it can be serviced unlike the Jetsons. Or so I thought, anyway. A mishap involving a user manual that doesn't match the model and inexperience in assembly led to my front wheel pulling off the dropout and damaging the motor cable. The digital display cycled through error codes for communication, throttle, and motor problems and then settled on just motor error. I contacted customer service and they don't think the motor itself is damaged, just the motor cable. They said they'd send me a new one, but it's been a couple of days with no contact and none of the shipping services show a shipping label, so I've been researching what I would need to do to fix it myself should I have to. I'm also anxious that the motor is fried, since I have no way to know without the cable. I have a disability that prevents me from riding anything entirely person-powered, so my brand new trike is useless til the PAS is working again. I'm anxious to get riding again! There are plenty of 9-pin female motor cables available, but all of the ones I've seen have the six thinner wires feed into a connector that has them arranged in two rows, but mine has them laid out in one row. What's the deal with that? Is my only option soldering a new connector? Neither the motor nor the controller have manufacturer markings so I have no idea who made them. I can solder a new connector, I've soldered before. But I'd rather not if I don't have to.

 

[E-HP]

Is my only option soldering a new connector? Neither the motor nor the controller have manufacturer markings so I have no idea who made them. I can solder a new connector, I've soldered before. But I'd rather not if I don't have to.

That’s not uncommon. My Crystalite controller uses one. The common square white 6 pin is common with a lot of controllers though, and for most of the cheap no names. When you replace the connector, just make sure you test before finalizing the replacement, since there’s a decent chance that the correct configuration may be one where the conductor coloring is not matched between the controller and motor, so you may need to do some swapping before you’re done.

 

[docw009]

A flat 6 pin JST going into the motor cable is not uncommon, I have seen them in one commercial ebike I had. The one in your picture seems to have the right color scheme. Red.Black for 5 volt power. White for speed sensor, Tellow, Blue, Green for hall sensors.

Every premanufactured motor cable I've seen does use a white 2x3 connector and three bullets, It should work if you match by color. If not, there's a methodical approach where you switch connections and ut doesn't jae more than a few trials to logically find the right combo,

My question is ...if you spun the motor out f the front fork, what usually gets ripped apart is the cable coming out of the motor. Why are you replacing the cable coming out of the controller then?

 

[SnowFox102]

My question is ...if you spun the motor out f the front fork, what usually gets ripped apart is the cable coming out of the motor. Why are you replacing the cable coming out of the controller then?

It's not me, it's the company I bought it from that suggested that. My thinking was that the cable coming out of the motor was wrecked too but they don't think so. There's no visible damage to that part, while there is visible damage to the controller side of things. I'm sure their plan is to try replacing the cheap part before replacing the entire front wheel with motor.

EDIT: The reason I think the cable coming out of the motor is damaged is because it has the locking mechanism Z910s sometimes have, and it didn't come undone so it was getting pulled on too. What probably caused the damage to the controller cable was friction, as I didn't initially notice that the wheel was off and had to push it somewhere safe to look at it. The motor side was wrapped around the axle, and the controller side was between the fork and motor, getting rubbed against the motor by the crooked wheel. My father worked in electronics for decades and taught me never to pull any kind of cable, as that can damage them. I suppose the motor end being wrapped around the axle could have reduced the pull somewhat, and I have seen repair videos showing people really yanking on that cable, but I still have my doubts. Here's what it looked like when I got a look at it. The wheel didn't come off entirely, just fell out of the dropout. No idea what happened to the bolt for the torque arm. I got the tracking number for the replacement cable and it will be here as soon as it ends its impromptu tour of the country, so I'll know more about the extent of the damage before long.

 

[amberwolf]

. My thinking was that the cable coming out of the motor was wrecked too but they don't think so. There's no visible damage to that part, while there is visible damage to the controller side of things. I'm sure their plan is to try replacing the cheap part before replacing the entire front wheel with motor.

Given the specific failure / incident, there is no reason that the controller-side of the cable would be damaged. Do you have any images of the damage? It may help us help you narrow down the problem.


There are many reasons for the motor-side cable to be damaged in such an incident. Most commonly it is right at the axle exit. Sometimes it's obvious, sometimes the wires are all twisted up inside but the outer jacket is intact. The insulation between phases (and often halls) is usually damaged, allowing shorts between these. This almost always blows up the halls in the motor, and often blows up the FETs in the controller, and sometimes the MCU.

 

[SnowFox102]

Given the specific failure / incident, there is no reason that the controller-side of the cable would be damaged. Do you have any images of the damage? It may help us help you narrow down the problem.


There are many reasons for the motor-side cable to be damaged in such an incident. Most commonly it is right at the axle exit. Sometimes it's obvious, sometimes the wires are all twisted up inside but the outer jacket is intact. The insulation between phases (and often halls) is usually damaged, allowing shorts between these. This almost always blows up the halls in the motor, and often blows up the FETs

It makes sense you'd doubt that the controller side is damaged, but I can assure you it is. Here's some more pics. The only visible damage to the motor side is some abrasion to the plug, but the controller side has two spots where the outer sleeve is worn off, presumably from when I had to push it to a safe location to take a closer look. I got the best shot I could of the place where the cable exits the motor as well. It's a tight spot but I can't see any damage there, so if it is borked it's internal.




This thread all but confirming my suspicion that the motor itself is the problem is making me all the more upset that the cable skipped over Memphis and went to New York and is out for delivery there. That's halfway across the country from here!

 

[SnowFox102]

Hoo. So now the replacement cable has a notice on it that the postage hasn't been paid so USPS is holding it. Uh, not sure how you get a package from the west coast to the east coast without paying for it, but here we are. In addition, I had my dad check the damaged cable's ability to carry current and it passed, which doesn't rule out shorts but does still imply that the motor is more likely the problem. Though now I'm questioning whether the company can replace it and I'm wondering what it would take to replace the motor myself but use the same battery, since it's new and batteries are expensive. Bafang is good right? Too bad they don't seem to do 36v...

Can this please stop being a whole saga?

 

[gromike]

Can this please stop being a whole saga?

Using good torque arms is a good start.

 

[SnowFox102]

Using good torque arms is a good start.

That advice would be helpful if you included examples. I did use the torque arm that was included and had no reason to think it was insufficient.

 

[gromike]

You have your reason now.

Torque Arms - Ebike Parts

We now have a full range of 7 torque arm models in production that together fit almost all front/rear 12 and 14mm axle motors, along with special ones for regen braking use. We also offer motor-specific arms for the Grin All-Axle and GMAC motors.

ebikes.ca

 

[docw009]

You're waiting for a cable like this then, except the white connector will be a 1x6 flat plug to fit your controller?


It might be helpful to pick up one of these tester boxes. While they're intended to plug into a 2x3 molex connector, you can connect a 1x6 to it. It will tell you pretty quick if the hall sensors still work, Ditto for motor continuity,

Your Dad could probably do that himself. Plenty of sources on the internet for Hall sensor testing. The red and black wires are 5V power/ground, The yellow, green, blue are open collector hall sensor outputs for wheel position. The white is a hall sensor output for rpm. , That should be enough for your old man. The Hall sensors only fire when you spin the wheel backwards. The speed sensor fires either direction,

Is that a factory sticker on the fork stating 30-35 nm for the axle nuts?

 

[d8veh]

You get motor cables from Aliexpress, Ebay or Amazon. Aliexpress is the cheapest at about $5 inc. shipping. It's very rare to find one with the flat black connector, so normal routine is to cut and solder each of the 6 wires if you have a mismatch.

Your main cable to the controller is damaged, so needs replacing, but I can't see how the cable coming out of your motor could survive what happened. Unfortunately, it's a much bigger job to repair that cable, as you have to dismantle the motor and do lots of soldering.

The worst news is that when a motor cable gets damaged, there's nearly always substantial consequential damage. It typically takes out the hall sensors, but it can also blow the controller MOSFETs and/or wipe out everything on the 5v rail - throttle, PAS, speed sensor and controller CPU, especially if you saw the code for communication error.

Before going forward, you need to test everything is individually functioning, starting with a MOSFET test, then the motor hall sensors. You can test the halls through the motor cable by powering it through the motor cable with the controller switched on, then turn the motor BACKWARDS while you check the pulses on the three hall wires with a voltmeter. The easiest way to test the MOSFETs is to disconnect everything from the controller and measure the resistance between the red battery wire and each phase wire, then repeat for the black battery wire. Each group of three should be the same as each other and in the range roughly 3k to 24k. Any zero readings or anomolous ones indicate that you need a replacement controller.

Motor cable damage is probably the most serious problem you can get on a normal ebike like yours, so you should always take every possible step to avoid it.

What typically causes front wheel spin-out is the lawyers lips around the drop-outs. The new axle is a different diameter, so the first washer no longer fits within the dimple. Instead, it lies at an angle on points instead of on a flat surface. When you start using the motor, the points distort and loosens the grip, leaving you with loose nuts. You must always inspect that whatever lies over the dimple (lawyers lips), sits completely within it. You can achieve that by filing the drop-outs deeper to compensate for the axle or grind your washers into an eccentric shape, or you can buy ebike specific eccentric or C-washers.

 

[SnowFox102]

Is that a factory sticker on the fork stating 30-35 nm for the axle nuts?

Yeah that's the cable I'm waiting on, and that is a factory sticker with the torque for the axle nuts. I don't have a torque wrench, and the instructions just said tighten them down really hard. Which I did, so much for that! My dad and I used a multimeter to check the continuity of the cable and it has that, so yeah it's probably the motor. At this point it's probably not worth it to me to test the motor, but I'm glad to know there's a tool that can do that.

Motor cable damage is probably the most serious problem you can get on a normal ebike like yours, so you should always take every possible step to avoid it.

What typically causes front wheel spin-out is the lawyers lips around the drop-outs. The new axle is a different diameter, so the first washer no longer fits within the dimple. Instead, it lies at an angle on points instead of on a flat surface. When you start using the motor, the points distort and loosens the grip, leaving you with loose nuts. You must always inspect that whatever lies over the dimple (lawyers lips), sits completely within it. You can achieve that by filing the drop-outs deeper to compensate for the axle or grind your washers into an eccentric shape, or you can buy ebike specific eccentric or C-washers.

Yeah, given what I've learned here my plan now includes investing in a good quality torque arm (I'm thinking this one by Grin should work) and checking the axle nuts before every ride. Maybe get a torque wrench to make sure the nuts are as tight as they should be, though I'm not sure I'm strong enough. I'm not entirely sure my fork has lawyers lips but as ubiquitous as they sound, it probably does so I'll see what I can do about that as well, thanks.

I really didn't expect a problem as serious as axle spin-out, given my rides are short (5 miles at a time is impressive), on flat paved roads, and at speeds less than 10 mph. I have hypophosphatasia, a metabolic condition that severely limits my strength and energy. I've been getting treatment for a year and just now am strong enough to ride, so I'm very anxious to make up for lost time. So if I sound over-eager to get back on the road, bear in mind I spent the last 20 years barely able to move some days!

 

[slaphappygamer]

if you got a text from USPS stating that postage hasent been paid, DISREGARD IT! It’s a scam. USPS will never text you. Ask me how I know. Lol

 

[SnowFox102]

if you got a text from USPS stating that postage hasent been paid, DISREGARD IT! It’s a scam. USPS will never text you. Ask me how I know. Lol

Haha yeah I know that much! I'm talking about the tracking page, accessed by going to usps.com and entering the tracking number. I'm not immune to scams but I do know not to follow any unexpected links and always type in urls manually! I kinda think USPS had a scanning error of some sort and they'll fix it on their own, but I sent a message to the bike company anyway.

 

[d8veh]

Yeah that's the cable I'm waiting on, and that is a factory sticker with the torque for the axle nuts. I don't have a torque wrench, and the instructions just said tighten them down really hard. Which I did, so much for that! My dad and I used a multimeter to check the continuity of the cable and it has that, so yeah it's probably the motor. At this point it's probably not worth it to me to test the motor, but I'm glad to know there's a tool that can do that.



Yeah, given what I've learned here my plan now includes investing in a good quality torque arm (I'm thinking this one by Grin should work) and checking the axle nuts before every ride. Maybe get a torque wrench to make sure the nuts are as tight as they should be, though I'm not sure I'm strong enough. I'm not entirely sure my fork has lawyers lips but as ubiquitous as they sound, it probably does so I'll see what I can do about that as well, thanks.

I really didn't expect a problem as serious as axle spin-out, given my rides are short (5 miles at a time is impressive), on flat paved roads, and at speeds less than 10 mph. I have hypophosphatasia, a metabolic condition that severely limits my strength and energy. I've been getting treatment for a year and just now am strong enough to ride, so I'm very anxious to make up for lost time. So if I sound over-eager to get back on the road, bear in mind I spent the last 20 years barely able to move some days!

The photo in your post #4 clearly shows the dimple in your drop-outs. Whatever goes up against that needs to fit within it. Your torque arm was not able to fit because it's the wrong shape. You need a washer or something similar underneath it. Whatever is up against that dimple on both sides of the bike must fit within it otherwise the wheel will come loose again.

 

[SnowFox102]

The photo in your post #4 clearly shows the dimple in your drop-outs. Whatever goes up against that needs to fit within it. Your torque arm was not able to fit because it's the wrong shape. You need a washer or something similar underneath it. Whatever is up against that dimple on both sides of the bike must fit within it otherwise the wheel will come loose again.

I see. Not what I was hoping to find, as I'm not sure I have the equipment to file them. Just a Dremel-type tool. Also not knowledgeable enough to know if the "universal" arm I ordered from Grin will fit into the dimple and not need filing. It's the Grin V5, but my frame is one of those generic Chinese things so who knows. Thank you for your help!

Incidentally, I did talk to the company again and told them about my research and the results of my continuity test on the cable. They still think the cable will fix everything, and wouldn't agree to send me a new motor until the new cable has been tested. A reasonable request normally, except I also asked about buying a motor and they still wanted to wait! Also the guy I talked to didn't know what a torque arm is and didn't know why axle spin-out would cause motor damage.

 

[docw009]

Your front fork motor projects often have a recess like that around the axle. Implies the fork wasn't meant for a motor, but you should be able to slip a washer in there. I understand this is a factory build, they should have included one, plus a drawing on how to use it. I see the side with the cable uses a plate that screws into the fork, The plate should have been able to lock the slotted axle. Did you not screw it into the fork originally?

You know, if the existing cable has already been verified to have continuity (I missed that comment) and the motor doesn't spin, then it's probably what everyone has feared. Motor cable is damaged.

 

[SnowFox102]

Your front fork motor projects often have a recess like that around the axle. Implies the fork wasn't meant for a motor, but you should be able to slip a washer in there. I understand this is a factory build, they should have included one, plus a drawing on how to use it. I see the side with the cable uses a plate that screws into the fork, The plate should have been able to lock the slotted axle. Did you not screw it into the fork originally?

You know, if the existing cable has already been verified to have continuity (I missed that comment) and the motor doesn't spin, then it's probably what everyone has feared. Motor cable is damaged.

It didn't come with a washer, and was missing one of the small torque arms that the manufacturer wants on both sides of the wheel. The instruction manual doesn't say that there are supposed to be two (it also calls it a "gasket") and I didn't know better at the time, so I installed it on the motor side because there's a picture of that. It wasn't enough to stop the spin-out though. I think that's the plate you're referring to, it just sits between the fork and the axle nut and also bolts into the fender eyelet. It's probably supposed to fit the lawyers lip, I don't recall offhand if it does though and I can't go check right now.

When this is over and I'm back on the road, I'm writing down everything I learned so maybe in the future someone else buying a cheap factory build can know what they need to replace and monitor.

 

[amberwolf]

When this is over and I'm back on the road, I'm writing down everything I learned so maybe in the future someone else buying a cheap factory build can know what they need to replace and monitor.

Thanks--that is what this site is about--sharing info to fix and build things.

 

[slaphappygamer]

Don't forget, you can also bookmark posts for future reference.



Just click on the chimney.

 

[SnowFox102]

Starting to wonder if the company is ghosting me, as I haven't talked to them since Sunday. This morning I left another message, and prior to this they'd replied within the same day. Still willing to do business with them if they take responsibility for the missing torque arm and manual not mentioning it, but losing hope enough that I'm learning what I can of the technical stuff to fix it myself. What I'm wondering is if I can get a new motor that matches the specs of the battery and controller I already have. I have a tester and new controller cable coming tomorrow so I'll be able to determine for sure whether it's the motor or cable that's broken. I mapped out the pins of the existing cable so I can be sure everything matches up, which brought up another question: With a new motor, how do I know what each pin of its connector does? Is there a way to check that, or does it not matter as long as the connectors match?

I like learning but I'm not quite as good at it now as when I was younger, and electricity was always a weak point!

EDIT: I've been searching for info, and finally came across this post with a flowchart for getting an unknown motor to work with a controller. Sounds like I'm not going to fry anything!

 

[d8veh]

Starting to wonder if the company is ghosting me, as I haven't talked to them since Sunday. This morning I left another message, and prior to this they'd replied within the same day. Still willing to do business with them if they take responsibility for the missing torque arm and manual not mentioning it, but losing hope enough that I'm learning what I can of the technical stuff to fix it myself. What I'm wondering is if I can get a new motor that matches the specs of the battery and controller I already have. I have a tester and new controller cable coming tomorrow so I'll be able to determine for sure whether it's the motor or cable that's broken. I mapped out the pins of the existing cable so I can be sure everything matches up, which brought up another question: With a new motor, how do I know what each pin of its connector does? Is there a way to check that, or does it not matter as long as the connectors match?

I like learning but I'm not quite as good at it now as when I was younger, and electricity was always a weak point!

EDIT: I've been searching for info, and finally came across this post with a flowchart for getting an unknown motor to work with a controller. Sounds like I'm not going to fry anything!

All the stuff you've shown is standard Chinese ebike kit stuff that you can buy from Aliexpress very cheap. It'll be substantially more expensive if you buy any parts from the company that sold you the Trike. In most cases, the parts can be replaced or upgraded to better ones, if you know what you're doing. If you need anything else to be replaced, post exact details about it so that we can make suggestions about where to get it.

 

[SnowFox102]

All the stuff you've shown is standard Chinese ebike kit stuff that you can buy from Aliexpress very cheap. It'll be substantially more expensive if you buy any parts from the company that sold you the Trike. In most cases, the parts can be replaced or upgraded to better ones, if you know what you're doing. If you need anything else to be replaced, post exact details about it so that we can make suggestions about where to get it.

Unfortunately what I need is the motor, and the one I have doesn't have any distinguishing marks. It has some kind of part number but I already tried googling it and didn't get anything. I also probably need it to already be mounted on a wheel. I can change a tire with some difficulty, but I don't know if I'd be able to build the whole thing from scratch. My strength and stamina are limited, that's why I went with off-the-shelf to begin with. :/ Obviously I could buy a kit, but I don't have the funds for that right now and won't for some time. So the only options for getting this trike working are getting the company to replace the motor, or finding one elsewhere that can be installed with my existing controller and battery. Here's what little data I have:

This is the trike I got
Motor is 36v 350 watts. Wheel is 20". Instructions say it can go up to 540 watts.
Battery is 36v 10.4 AH
Controller has no identifying marks either, it's also a standard Chinese model. It connects to a digital display (which works). Instruction manual says it can be set to use 24v, 36v, or 48v batteries.

What I'm wondering is if it's possible to get another 36v motor, such as this one, and have that work. Or are motors and controllers paired? I'm generally pretty good at researching things but with the AI slop clogging things up it's a lot more difficult finding useful information nowadays.

 

[docw009]

Your motor connector appears to have a red o-ring inside it, and is probably threaded? If so, that's why it didn't pull off and got further twisted. I'm not familiar with that connector.

Most low power motors use a simpler Z91 connector, like that ebikling motor. You would have to buy a standard motor extension cable with a Z01 and attach that to your controller to use off the shelf motors. No big thing. Adds $15 to cost of new motor,