kctrading

I just picked up one of these from a bike shop that sells seconds... they do not repair them just sell bikes.

This is a brand new 2021 Nakto Fat Tire Bike 4.0x26" It has a 36V battery pack. I paid $350 for it.

Here's what it's doing:

LCD powers up ok... I can get the LCD panel to power up and it shows full power. But there is no power to the motor.
When I hit the power it gets a momentary blip that it's getting power for a second then disappears ....when I pull the brake handles that blip on the LCD
does not show up. Would seem the brake switches are ok? I was told by the seller that it could be a bad motor or controller... but it would be nice if it was
something cheaper : )

Anyone else run across this?

I'll try to post some pics tomorrow
Any suggestions?

dedhed

Like any electrical diagnosis follow the electrons

HillRider

I assume the seller not only doesn't do repairs but offers no warranty? Can you contact the manufacturer for some troubleshooting help?

Crankycrank

I recommend asking the moderators if you can move this to the "Electric Bikes" section. Probably a greater number of experienced folks over there.

2old

Agree ^^^. Did you try it before you made the purchase? I would return, if possible. Otherwise, without any more info, sounds like the battery is shot, easy enough to check if you can borrow one.

3alarmer 

.
...find someone who does electrical diagnosis (like cars or other electronical stuff), and pay that person to run down the issue. I used to do automotive electrical, and you can spend a lot of money replacing stuff that is not broke, if you don't have some basic diagnostic tools and some knowledge of how your thing works. Any guesses anyone gives you here on the internet will just be chasing squirrels.

Stuff like putting in a battery you know is good and fully charged is something you can do, but if you need to buy a battery to do it, it's not a cost effective solution. Unless you do need a new battery.

Why would you buy an electric bike you know from your discussion with the seller is busted, unless you know how to fix stuff like that yourself ?

CliffordK

You'll have to go through basic diagnostics. Pull the battery and see if you can physically verify the voltage. And, if possible, voltage drop when in use.

See if you can figure out how to hotwire the motor. Is that a mid-drive? There are a couple of big mid-drive manufacturers, but that may be a Chinese clone.

Keep an eye out for loose, bent, damaged connectors.

alo

It gets down to how much you understand electrical circuits yourself. If you know what you are doing, you can get information about that particular bike, and check it out yourself. If you have no idea about those things, find someone who does.

How much do you understand about electrical circuits? If someone told you what to check, would you understand what they are talking about?

There are even issues like, you may need to enter a pin code to turn it on.

A lot of electric bikes from China with small wheels are being sold here for around $300 to $400 new. I am waiting to see if, in a few years time, people sell them for $50 not working. There will probably be someone who can fix them, and they will probably sell for more than that, but see what happens.

alo

Here is the website. See what you can find out here.

https://www.e-bikes.com/collections/...fat-tire-ebike

alo

Most electric bikes have brushless motors. So you would hot wire the controller. This is probably what you meant.

alo

The first thing to check would be voltage drop when you try to get it to go. If there is a big voltage drop, buy a new battery. They sell them on the website linked in a previous post.

alo

Another option is to connect 3 old style filament car headlights in series, and connect them to the battery, and see how it goes. They should not draw as much power as the motor, but you should be able to see if they light up, and stay lit up for a long time. this should give you an idea of the condition of the battery.

alo

There are a number of videos here.

https://www.e-bikes.com/pages/help-center

Here is one.

https://www.e-bikes.com/pages/check-ebikes-problem

kctrading

Battery us good as the other 20" bike uses the exact same battery. Today I noticed the wires at the motor have been damaged/cut. This is 350W 36v motor (see pic) can I take it apart and replace the wires? I fly RC planes too so have everything needed if it can be done

I hope this didn't takeout the ESC too? :/

kctrading

I agree...found some cut wires...I need 10 post to attach some pics....ugh!

kctrading

links....


I'll ck them out, thks

kctrading

Ck what I found so far....

kctrading

10th post.... I'll send some pics now

CliffordK

Another day for #11?

alo

Yes. Replace the wires.

It seems like you got a bargain, if it is only a minor repair.

kctrading

I added two pictures to the original post. I have a 9 pin cable coming from Amazon rated to 5pp watts. This has a 350 watt hub.

Any tricks in removing hub? One thing is I don't have puller. Can it be done without one?

I want to check the sensor while I'm in there. Watched couple YouTube videos on this.

Not sure about the ESC condition....Motor green wire was cut in two all but white sensor wire were cut in two... from shipping. I can get a original replacement for $20.

speedy25

Nice chop up on the motor cable!!

If you are handy, and can solder, you can replace it. Most people arent and they send them to me for repair.

I dont know what your "replacement" for $20 is.

And just like crankycrank posted, this thread should have been moved to the e-bike forum. E-bike content has always been moved in the past.

-SP

shelbyfv

They seem to have a new policy of not moving threads to the appropriate forum.

Buzzkill53120

I looked at the photo and all ten leads are either cut or damaged. I don’t know anything about the hub, can it disassembled and new leads replaced? If that’s not the case I don’t see anybody able to repair the leads, especially the insulation (shrink tubing) as there isn’t much space going into the axle. I wouldn’t even want to power that up given how the leads look.

kctrading

I received the replacement lead that will need to be re-solder them to the motor once I disassemble it.... per the youtube videos it's looks pretty easy...thanks