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Rear wheel locked, lcd registering throttle wattage, no response from motor

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Long time listener, first time caller here 

So I will try to keep this short...

Bought a used fatty a year ago and it sat in storage for a bit over winter... I took it out and tried to move it, and the rear wheel was locked up and wouldn’t go backwards.. Have been poring over this page and the Facebook page  and I’ve gotten pretty far but now I need some advice

I’ve replaced the throttle (the button was broken so was needed), and upgraded the controller (it came with the bike so I figured why not while I’m at it...) I didn’t think those were really solutions, so no surprise when that wasn’t a fix.

Ao now the throttle works.  I press down, the voltage is reading in the lcd and I can hear a “click” in the motor. But no response/movement otherwise.... 

am I correct in assuming this is a motor issue? Have checked all cable connections and they are good.  Tested the battery, it read at 38 when off and went up to 40/41 when on... so seems like battery is good...

I thought I might take it apart and check, the Luna motor instructions made it seem like a simple 3 step  easy removal.. so I finally removed the rear wheel and then got to “Remove the sprocket...”

I’ve read everywhere that removing the sprocket will destroy it soooo... before I destroy my sprocket and take apart my motor... are there any other issues I could check?? Or am I right in assuming it’s a motor issue?


the sprocket is pretty rusty... there’s a good amount of rust in places there probably shouldn’t be rust....  I have some simple green cleaner/degreaser but would really appreciate  some advice on  removing  rust tooo!!

And I guess while I’m here, and if it’s needed, can anyone recommend a good replacement sprocket/motor?? Is luna good, despite their instructions are not so simple as they seem?  what confuses me is that they don’t think you will need a new sprocket, or is that included?

Thanks for listening y’all, hopefully my bike isn’t a total lost cause...

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Hello @DinoPizzaJamz I’ll assume you have a first or second generation Sondors Fat with a 36V canister/bottle/bullet  battery. Include a picture of your bike.  But it’s important to know which. The fact that you probably switched controllers back to the original and if your bike is an second generation Kickstarter Campaign bike it might not be compatible with an aftermarket LCD, that you might be using. The normal first upgrade, that owners do to increase performance , is to upgrade to a higher amperage controller. First generation Indiegogo Bikes are compatible with any aftermarket controller,  second generation Kickstarter Bikes  require an aftermarket controller & LCD combo, to maintain compatibility. Does the LCD say SONDORS on the top perimeter of the case?  And you rode this bike last year?  Now that you have the back wheel off does the motor turn in both directions? Have you ridden the bike in water, ocean or lake?  The fact that you report a lot of rust on the Freewheel might indicate that there is a build up of rust inside the motor, that has very tight tolerances.  You do not need to remove the Freewheel to get inside the motor case. Removing the case perimeter screws with allow the motor to separate from the case and you should be able to access   damage inside the housing  before further disassembly. 






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Thank you @Reddy Kilowatt for the response! Attached  is a pic of my bike.

The LCD is Sondors. I had swapped out the throttle before swapping out the controller, and when I tested it then, it was doing the same thing... The  bike was working  fine with the LCD/Controller combo when I was using it last year but it's been about a year since I rode it, and I had it covered through winter but I think some rain  may have gotten to it :( 


" Now that you have the back wheel off does the motor turn in both directions?"

How  do I turn the motor? Do  you mean the free wheel? If so, then no, it is still locked in the  other direction....

Now that I know I can remove the motor without destroying the freewheel, I  will give that a go and see what's inside! Stay tuned...


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It’s really important to keep eBikes in an controlled environment. Changes in temperature and humidity alone, can cause condensation inside all its parts and that breeds rust on anything steel. 

After the wheel is off, be careful not to bend your brake disc, a simple egg or milk crate will help when changing flats or otherwise protecting both sides of the wheel, (my crate in over 30 years old and I cut foam pipe insulation to further protect the spokes) you can buy similar crates at Walmart for $3.44. You turn the motor shaft .... It will resist because of the magnets but you can use a wrench on the axel nut. You don’t have to spin it just make sure, besides the magnetic force, nothing is binding or impeding rotation.  I just did this today on my own EBL, to make sure the new motor,  I have installed in the old case fits properly. 


When removing the 6 motor cover screws, they should be Phillips (newer motors have Torx screws with security pins. Takes a special Torx Bit. Your motor cover screws will me tight and the best way to remove them is with a screw gun with an adjustable ratcheting clutch, and a good philips bit that fits properly. Start out with a lower slip settingnsnd the the ratcheting clutch hammer the screws loose.  Be careful not to strip the heads or threads, the metal is pretty mild.  Leave the disc side axel nut on that side of the axel screwed on flus with the axel end. Then with a little force, bump that end in the floor and that should dislodge the motor from the case. 

Now you should be able to see the gap between the magnets on the inside perimeter of the motor and the rotor’s stator windings. That’s where you might find your problem.

This is where I buy my 750Watt motors but they require  35Amp controller and a battery pack of at least 48V and something like 14 to 30 Ah to make the motor perform.  https://eunorauebike.aliexpress.com/store/904105?spm=a2g0o.detail.1000002.2.1521141aounh76.     US vendors used to stock 350watt Bafangs but mostly now they stock 750Watt upgrade motors.  Just make sure, if you need to replace your motor you get a direct replacement that fits. 





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@Reddy Kilowatt thank you so much for the detailed instructions, they were very helpful!!! I wound up using an old basket to hold my wheel up it definitely helped, thanks!

So.... I tried to  turn the motor, and it still wouldn't turn the other direction....

Took off the motor cap to discover quite a wet rusty mess 😥


So..... looks like I need a new motor :(

I have a 36V battery, and this is the controller that I was given when I bought my bike (the guy had bought it and just never installed it) https://electrobikeworld.com/products/25amp-controller-with-higo-connectors?yotpo_token=ebb96f50eba7170d0f3be86fcf971ef670ac5663&utm_source=yotpo&utm_medium=email&utm_campaign=map

I unfortunately don't have the funds for a full upgrade, so will try and search for a 36V 350W or 500W motor.... Hopefully there's someone in the US with one...

Do you think I should replace the sprocket too or will that be fine? It's pretty rusty.... IMG_2032.thumb.jpeg.22ce1330250decc8f41e32eb8d45b310.jpeg 

Definitely learned my lesson on proper storage, the hard way, yeesh!!! 

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If I were you I’d post WTB on the Sondors Storm Owners Group on Facebook. Once there ask to join. I’m no help on the procedure to buy and sell goods there because I don’t FaceStool, on principle, but because many owners upgrade their 350watt motors, there should be someone willing to sell theirs complete with Freewheel.  That said I think you can buy the direct replacement from China for about $135.00 free shipping. I’ve paid $160 and change for my first 750W and 2 years later, last November, $177 for the second, during  their sale holiday, on aliexpress, November 11th if I remember.    

You’ll have to buy a new Freewheel, if you buy a motor without one, because the only way to remove yours,  is to destroy it. Yours has suffering the same fate as the motor, it just  hasn’t failed YET, but the steel bearings and spring pawls are very delicate mechanisms and are most likely doomed.   https://www.parktool.com/blog/repair-help/freewheel-destructive-removal

I’ll post pictures tomorrow of my Bafang 750WATT motor with over 10,000 miles but it looks new inside and even the nylon reduction gear  cluster shows no wear. I was really surprised at how good a condition it is in. 






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The saga continues!!! Thanks to all your help @Reddy Kilowatt I bought a used motor... and went to swap it out and my casing is quite a mess....

does it look salvageable? Or do you think it’ll mess up my new motor? And if it’s not gonna work.... how difficult is it to relace my spokes 😬😬😬😬

One day I will have a working bike..... hopefully that day is soon....


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As long as the bearing is OK or salvageable I think with some naval jelly and elbow grease and a soft wire, Copper or Brass circular wheel brush in a cordless drill motor, it should clean right up. I’m not sure where you might find a replacement bearing but they are replaceable, if it’s bad. 

It would probably cost north of a hundred bucks to have a bike shop respoke your new motor in your wheel. It’s something you’ll want an experienced shop to complete. 



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