Hub plate came off while riding

[EbikeNewBee]

Hi, I just got my first ebike. It was 80% assembled and I put it together and tested it for 2 miles and all is good. Today I went on a longer drive using lowest pos and 5 miles out I heard some grinding and pulled when I could. The screws keeping the hub motor together were gone. My question is what are the size of the missing screws? I assume they are metric.

My second question is type of damage could occur with this type of failure. It is dangerous condition since you lose your rear braking.

I opened a ticket with the seller listed on Walmart but I expect it will a long process.

Any help would be appreciated.

Thanks

Tim

 

[Annieolnie]

Do you have any of the machine screws left? You can simply take out one more and bring it to the hardware store to put into the thread checker on the wall. You will need to check the size and the thread pitch. You might also want to pick up some blue thread locker, which will hold things tight but can also be undone. Could you tell us the make and model of your new bike that came seemingly hanging by a thread?

 

[Atavar]

From your pictures it doesn’t look like the screws fell off, it looks like they broke off and there are stubs left in the motor.
First off, don’t do anything until you settle with the seller. If you do anything they could claim you voided the warranty.

 

[EbikeNewBee]

Thanks for the replies. The screws came off while riding so I don't have any to compare with

I rechecked the holes and are open so there are no studs left in the holes.

I'm at a lost how it could if happened. I imaged they didn't use lock right or they just didn't work them enough.

I am wondering what kind of additional damage I should look for and what size screws would be likely. If they offer to just send me screws I would have to wait a week to find out if this is the only problem..

 

[EbikeNewBee]

The bike is a

PEXMOR Electric Bike for Adults, 750W 48V 12AH Removable Battery 26" Fat Tire Folding Ebike Adult Electric Bicycle, Full Suspension Mountain Snow Beach Commuter E-Bike, 21 Speed

 

[Annieolnie]

Well, you've got me curious, I don't have a Pexmor but I pulled a bolt from my hub and it is a 4mm button head hex that is 10mm long. It takes a 3mm hex key. Pexmor has their own website and they say they will get back to you in 24 hrs. so you could try and double check with them. I will post a pic from Amazon.

 

[HumanPerson]

pexmore is voilamart just sayin

 

[Annieolnie]

Ahh...I did not know that, once again, it is the wild, wild west of ebikes.

 

[Annieolnie]

The bike is a

PEXMOR Electric Bike for Adults, 750W 48V 12AH Removable Battery 26" Fat Tire Folding Ebike Adult Electric Bicycle, Full Suspension Mountain Snow Beach Commuter E-Bike, 21 Speed

So, human person has said Pexmor is Voilamart, so, unless you are planning on returning this thing, I think you are on your own. This box of button heads just came up on Amazon with a half off coupon, if you see this, I would grab it and then you can sort the issue out for yourself. Either way, metric button heads are useful. Good luck.

 

[HumanPerson]

it's very odd. I bought a 1200w pexmore then had some trouble with the controller so when i contacted the vendor he told me that
Voilamart and Pexmore were the same kits just different people or different names for the companies...
Then they sent me a Voilamart controller and everything works great again lol

So yas see...even ebikes like the Aventon are the same frames and or motors on other bikes...

This whole ebike sphere is weird really in my own opinion LOL

 

[HumanPerson]

From your pictures it doesn’t look like the screws fell off, it looks like they broke off and there are stubs left in the motor.
First off, don’t do anything until you settle with the seller. If you do anything they could claim you voided the warranty.

I just noticed that! Good catch

 

[Annieolnie]

Not to be obsessing or anything, but I just found your 26" hub motor wheel on Ebay. It's not like anything I've seen before. It appears to have a thicker plate, with flat head screws that are phillips head. I would go with a hex head anyway as it's easier to tighten properly with a hex key, but you do seem to need flat head, counter sunk and guessing by the size of the plate, probably 12mm instead of 10 in length. I'll post the pic. and you can see if it looks right, this would explain why the holes appear odd in your photo.

 

[Annieolnie]

Here are some other Amazon machine screws that should work.

 

[Atavar]

Looking closely at the pictures again I am going to guess this is a case of bad quality control and there were never any screws to begin with. It just held together on the short first ride due to press fit and/or paint adhesion.
It would be very unusual for all those screws to work loose and fall out at the same time.

 

[EbikeNewBee]

Thanks for all the feedback. Thanks annieolie for pulling a bolt. Your are correct it is a M4 10mm long and button head but the driver is 2.5 for the bolts have

I reconnected the hub cover. I had to move it around until I could get it to seat fully. I am assuming it has to aline with a gear. I didn't threadlock it yet but will after I test it.

I spent a lot of time in China. Typically you have a small set of manufactures and they will label and do limited customization for any number of resellers. So you will see basically the same bike sold by many resellers with little differences. The folding 26" ebike pexmor like the one I have are sold by many sellers with battery capacity and accessories differences . If you look at Alibaba you can find the manufacturer for a specific style of bike that is sold by many. This is not unusual practice. Sears, Montgomery wards do the same. The difference is that now there are huge number of companies and if one company gets bad reviews it easier to just shut it down and make a new one.




.

 

[EbikeNewBee]

I took it out for a ride and it works perfectly. No grinding and smooth. I think atavar is on to something. I can't figure out how all screw would loosen. Perhaps they just pressed the plate on and forgot to put the screws in at all. It is dangerous in that the rear disc brake will not stop the bike with a detached plate. I like to see what that will say when/if they respond.

Happy ebiken

 

[Brucegordon]

I took it out for a ride and it works perfectly. No grinding and smooth. I think atavar is on to something. I can't figure out how all screw would loosen. Perhaps they just pressed the plate on and forgot to put the screws in at all. It is dangerous in that the rear disc brake will not stop the bike with a detached plate. I like to see what that will say when/if they respond.

Happy ebiken

These days (I'm 70) When ever I get something (Mechanical) from anywhere I go thru it looking for the weak. There always is something, Even American made. I'm glad you caught it before more damage was done.