Reversing direction of mxus hub motor

saneagle

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Oct 10, 2010
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Hi, could anyone tell me please if you can reverse the direction of rotation of an mxus xf08 hub motor? Thank you.
It depends on which controller it is. If it's one of the cheap ones with a pair of self- learning wires, self -indentification or any words like that, do the self- learning procedure.
 

jarnold

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Oct 2, 2024
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I believe you need to swap two of the phase wires(the three thicker wires) and the corresponding two of the hall sensors wires. However, that may only work if it's a direct drive hub with no free wheel.

But I'm no expert.
 

saneagle

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I don't know whether it's a cheap one or not. It's a KT24/36SVPR-HRD01. There doesn't appear to be any indication on it.
If it's a KT controller, you have to swap the wires in the motor cable. I hope you didn't get one with the waterproof moulded connectors. I always warn against that.

Swap the positions of the yellow and blue hall wires and the yellow and green phase wires.

I'm assuming that the motor is whirring, but not turning the wheel. If the wheel is driving backwards, you have it on back to front.
 

Presterjohn

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Sep 11, 2024
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That's great thank you. I did get the controller with lots of wires and little connectors fortuneately. The motor is just a motor and I'm using it as a mid drive. I'm only thinking of changing the rotation because I have two chains that might foul each other. One is a on a fixie sprocket and the other a freewheel. I will try swopping the phase and hall wires tomorrow.
 

saneagle

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Oct 10, 2010
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That's great thank you. I did get the controller with lots of wires and little connectors fortuneately. The motor is just a motor and I'm using it as a mid drive. I'm only thinking of changing the rotation because I have two chains that might foul each other. One is a on a fixie sprocket and the other a freewheel. I will try swopping the phase and hall wires tomorrow.
If you mean it's rotating, but in the wrong direction, the solution is to turn it around. Alternatively, you can weld the clutch to stop it from disengaging, then do the wire swap I mentioned above.

I'm still not sure what the present situation is. You need explain clearly from the start.
 

Presterjohn

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Sep 11, 2024
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Hi, this is a new project I am looking at. I don't know if you are familiar with the Kosynier ebike? I'm making one like it but with the motor actually inside the V twin instead of in the back wheel. To get the chain lines to work you would need to run a chain from both sides of the motor. You can buy a fixie sprocket that fits the brake disc mountings but you can't get a derailleur that works on the 'wrong' side of the rear wheel so you need to have the motor reversed. The freewheel will go on the screw mounting and it can be reversed. The chain set will go on the other side and the freewheel goes either way round. That's probably not very clear but I hope you can picture what I am trying to do!
 

saneagle

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Oct 10, 2010
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Hi, this is a new project I am looking at. I don't know if you are familiar with the Kosynier ebike? I'm making one like it but with the motor actually inside the V twin instead of in the back wheel. To get the chain lines to work you would need to run a chain from both sides of the motor. You can buy a fixie sprocket that fits the brake disc mountings but you can't get a derailleur that works on the 'wrong' side of the rear wheel so you need to have the motor reversed. The freewheel will go on the screw mounting and it can be reversed. The chain set will go on the other side and the freewheel goes either way round. That's probably not very clear but I hope you can picture what I am trying to do!
I still can't understand what you're trying to do. A sketch or photo would help. When I made my DIY crank-drive bike, I needed drive from the other side of the motor, so I screwed a freewheel thread to the disc fixings, then I was able to screw on a normal freewheel.

I made the adapter by pulling the side off a cheap BMax pressed steel hub. There's a picture of it in this thread post #9:
 

Presterjohn

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Sep 11, 2024
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Thank you, that's a really helpful reply and the link looks just about what I am trying to do. I can't make out the pic in #9 very clearly but the bike in pic#13 is , expect for the overall look of the thing, what I want to make. Are you d8veh? If I understand the thing are you saying that the pedals drive the freewheel sprocket on the motor and of course the motor will drive the pedals which drives the rear wheel. The motor will stop when you stop pedalling if there is a sensor on the bottom bracket and there is a freewheel on the rear cassette so the pedals won't go round. When you pedal the motor will drive but it won't matter if the pedals are driven? [ They won't go any faster than if you were pedalling anyway]. I presume there is a double sprocket on the chainset and you take the drive to the rear wheel from that. Now if this works like this why did you need to take a drive from the other side? There isn't one in the picture. Sorry I can't post any pictures, most of this is in my head or on drawings in notebooks. The motor in the picture looks like it is fixed and the shaft rotates but that isn't a problem because I have made the V twin engine and the motor is mounted by it's spindle in the crankcase of the thing.
 

saneagle

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Oct 10, 2010
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I have done a sketch and took a pic of the crankcase
View attachment 63375
View attachment 63374
According to that photo, the motor is driving in the direction you want but won't drive a chain with a normal freewheel because it's freewheeling in the wrong direction, but you can fit a simple screw-on sprocket with an appropriate spacer; however, it would tend to unscrew whenever the motor applied power to it, so you need to find a way to stop it from unscrewing. You can't use anything fixed to the axle because the unscrewing would put an axial load on the bearing, which will wear it out quickly. I think if you make a custom spacer to go behind the sprocket that comes to just below where the chain needs clearance, you could fix it with 4 or 6 screws after drilling and tapping the side of the motor. I'm not sure how much thickness there is on that side, but with 6 screws, it should be OK.

That leaves the crank, which is easy because you can buy double freewheeling cranks from GNG and Cyclone. Eclipse bikes in UK are agents for Cyclone. I don't think there are any agents for GNG, but they give a pretty good service from China.

PS Nice casting. Did you do that yourself? Did you melt down all your old coke tins?
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
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BTW, I have a GNG or Cyclone double freewheeling crank, bottom bracket and arms if you're interested. I bought them for a project, but never used them.
 

Presterjohn

Pedelecer
Sep 11, 2024
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Hi , I see now that the crank has to freewheel, whereas you don't need a freewheel on the motor. I can just loctite the sprocket on the motor to its thread. If I use 638 it'll never come loose or i could use nut locking grade which would enable me to remove it. I have a fixie that will fit. I'll look into the freewheel crank, perhaps you could PM me with details and price of yours please.
The crankcase isn't a casting, it's an old saucepan! The cylinder mounts are fabricated from thin sheet and fixed with JB weld and body filler, the mounts are brazed onto the pan. I machined the base to take the other end of the motor. It machines pretty easy, it's thin stainless and aluminium in the middle.
You can buy those freewheels with mounting holes on Amazon, I have one on a little lathe.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
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Hi , I see now that the crank has to freewheel, whereas you don't need a freewheel on the motor. I can just loctite the sprocket on the motor to its thread. If I use 638 it'll never come loose or i could use nut locking grade which would enable me to remove it. I have a fixie that will fit. I'll look into the freewheel crank, perhaps you could PM me with details and price of yours please.
The crankcase isn't a casting, it's an old saucepan! The cylinder mounts are fabricated from thin sheet and fixed with JB weld and body filler, the mounts are brazed onto the pan. I machined the base to take the other end of the motor. It machines pretty easy, it's thin stainless and aluminium in the middle.
You can buy those freewheels with mounting holes on Amazon, I have one on a little lathe.
You can try it, but I'm pretty sure that locking compound won't hold it. The whole torque of the motor on that small diameter will be trying to unscrew it.
 

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