need help sourcing replacement nylon motor gears. Pics and specs in post

[mindgames11]

I have a Kuo A2B 20 inch folder that I was just getting to enjoy when I heard noises coming from the motor. took it apart and sure enough some of the teeth were missing and others looked like they were going.
I also don't know what to call it. when I search nylon hub motor gears, all I see are single gears, not double stacked gears like I've got here.

The lower gear is helical cut, 35 teeth, 38mm diameter and about 9.4mm tall
the upper gear is straight cut, 18 teeth, 25mm diameter.
the bearing in the ceneter is a 696z (which is/was in great shape incidentally).
Do I call these gears and where do I search for that alternatively if somebody wants to provide me a link I certainly wouldn't turn that down.

to conclude- if the gear is originally helical cut it has to stay helical cut correct? And the so-called benefits of switching to metal or any non-nylon material for the gear is potentially increase power handling at the trade-off of increased noise do I have that right?

Whatever the case may be I'm really just looking to get this bike back on the road.

Although I have ordered one of those 20 inch direct drive motors with the cast wheel that's all over the internet.
I ended up getting a rear wheel instead of the front even though I fantasized about the ease of swapping the front tire I really can't imagine feeling comfortable with all that extra weight particularly with a direct drive motor in the front.
If anybody knows what the general specifications beyond what the non-information that come from the Chinese sellers is I'd appreciate hearing it.

 

[glennb]

To find replacement gears you need to count the teeth on each of the gear sets, and measure the thickness and diameter.

You can buy individual nylon gears, you don’t need the whole assembled cluster, including clutch.

Yes, you can’t substitute straight and helical gears.

Noise is subjective. I don’t mind noisy scooters, but hate noisy bikes. Nylon is definitely your friend if you’re sensitive to noise.

 

[glennb]

There’s a fair few on Aliexpress. I think “nylon gear” is a reasonable search term, but Aliexpress’ search engine is a horrible joke. Probably be more successful using the tooth count as the search term.

 

[docw009]

AKM makes a good small motor. I have bought a few, and no gear fails. If the case cover unscrewed like a Martian spacecraft cylinder from War of the Worlds, it's an AKM motor.

https://www.aliexpress.us/item/2255799896745851.html?spm=a2g0o.productlist.main.1.228321bd4ZND08&algo_pvid=d4850bc0-3036-47e8-80b6-a9d5006c67aa&algo_exp_id=d4850bc0-3036-47e8-80b6-a9d5006c67aa-0&pdp_npi=4%40dis%21USD%2119.90%2117.71%21%21%2119.90%2117.71%21%402101c80217303895319445990e8cd4%2112000030552613960%21sea%21US%21742508029%21X&curPageLogUid=hTNgywqNdtJK&utparam-url=scene%3Asearch%7Cquery_from%3A

 

[mindgames11]

To find replacement gears you need to count the teeth on each of the gear sets, and measure the thickness and diameter.

You can buy individual nylon gears, you don’t need the whole assembled cluster, including clutch.

Yes, you can’t substitute straight and helical gears.

Noise is subjective. I don’t mind noisy scooters, but hate noisy bikes. Nylon is definitely your friend if you’re sensitive to noise.

(in my OP) I dimensioned and counted the teeth, however the term or combo of terms "nylon gears/hub/stack/dual" wasn't giving me anything- just single layer gears.

if there's a specific term for what the gear style that I have is, I'd love to hear it.

 

[mindgames11]

AKM makes a good small motor. I have bought a few, and no gear fails. If the case cover unscrewed like a Martian spacecraft cylinder from War of the Worlds, it's an AKM motor.

View attachment 361360

https://www.aliexpress.us/item/2255799896745851.html?spm=a2g0o.productlist.main.1.228321bd4ZND08&algo_pvid=d4850bc0-3036-47e8-80b6-a9d5006c67aa&algo_exp_id=d4850bc0-3036-47e8-80b6-a9d5006c67aa-0&pdp_npi=4%40dis%21USD%2119.90%2117.71%21%21%2119.90%2117.71%21%402101c80217303895319445990e8cd4%2112000030552613960%21sea%21US%21742508029%21X&curPageLogUid=hTNgywqNdtJK&utparam-url=scene%3Asearch%7Cquery_from%3A

sweet. this is the closest thing I've found so far.
it unscrewed by removing the freewheel (to free the axle), then three hex fasteners released one side of the motor case. I'll take some pics later.
if you know the term for the "dual stack gear", do tell!

 

[glennb]

(in my OP) I dimensioned and counted the teeth, however the term or combo of terms "nylon gears/hub/stack/dual" wasn't giving me anything- just single layer gears.

if there's a specific term for what the gear style that I have is, I'd love to hear it.

Correct terminology gets you nowhere on aliexpress, because vendors a) presumably assume buyers lack knowledge of terminology, and b) are trying to maximise search hits. Like I said, for a search term, try plugging in both the tooth counts. 35t and 18t? I’ve done it before trying to source Bafang BPM gear sets and it generated somewhat useful results.

 

[mindgames11]

Correct terminology gets you nowhere on aliexpress, because vendors a) presumably assume buyers lack knowledge of terminology, and b) are trying to maximise search hits. Like I said, for a search term, try plugging in both the tooth counts. 35t and 18t? I’ve done it before trying to source Bafang BPM gear sets and it generated somewhat useful results.

I really despise so many things about aliexpress- terminology meaning nothing. Along with most product descriptions, photos, nearly all user reviews (most of which are so comically ridiculous they make me laugh while making me angry.).

However, I did just happen upon what I believe is the correct item- for a bafang RM G310.250. correct number of teeth, measurements close enough (oh yea, the aliexp disclaimer that measurements may be off by 1-2 cm, which almost negates the point of measurements.

I looked up the bafang motor and sure enough- looks like what I've got.
Now to see if I can find it for less than $40.

I've got a direct drive motor in that bike now and except for the weight, quite like it

 

[mindgames11]

I ordered the gears and they arrived, although I'm not home right now. I should be installing them in the next days.

 

[software grunt]

However, I did just happen upon what I believe is the correct item- for a bafang RM G310.250. correct number of teeth, measurements close enough (oh yea, the aliexp disclaimer that measurements may be off by 1-2 cm, which almost negates the point of measurements.

I looked up the bafang motor and sure enough- looks like what I've got.
Now to see if I can find it for less than $40.

Hey, sounds a whole LOT like the Bafang G310 I have here: compound gear, 250W nominal rating. One way to tell: is there a thin set of needle bearings under each gear, to handle the small axial force from the helical gears? And is the helical sun gear metal?

My motor is dead, so I would be happy to send you this set of gears for free, if you want. Or you could order the set from GRIN:

G310-G311 - Other Motors - Our Products

The small G311 front / G310 rear motors from Bafang are well suited for those wanting light and discrete conversion for moderate assist levels. A high reduction helical gear set allows these tiny motors to deliver a surprising punch without any of the buzzing noise commonly associated with...

ebikes.ca

Just send me your street address (via email to grin@oregance.com). I'll send 'em; if they work for you, send me 25 bucks. If not, send them back. Fair?

 

[mindgames11]

Hey, sounds a whole LOT like the Bafang G310 I have here: compound gear, 250W nominal rating. One way to tell: is there a thin set of needle bearings under each gear, to handle the small axial force from the helical gears? And is the helical sun gear metal?

My motor is dead, so I would be happy to send you this set of gears for free, if you want. Or you could order the set from GRIN:

G310-G311 - Other Motors - Our Products

The small G311 front / G310 rear motors from Bafang are well suited for those wanting light and discrete conversion for moderate assist levels. A high reduction helical gear set allows these tiny motors to deliver a surprising punch without any of the buzzing noise commonly associated with...

ebikes.ca

Just send me your street address (via email to grin@oregance.com). I'll send 'em; if they work for you, send me 25 bucks. If not, send them back. Fair?

hey, don't know how I missed your posting until now. I'm about to be going to my apartment where the motor shell, old gears, new gears etc are so I can firm up reality for myself.

I also found ~%30 cheaper gears, cut in the left and right hand for the consumer to choose.

 

[mindgames11]

I hate googling something and finding my own question. I finally just got another set of gears in the mail... from grin. they're still slightly different- although in a different way. if anything kills this, it will be that the angle of the gear is cut slightly differently (although the overall height, the original not having needle roller bearings..) I'm just gonna try it since this ridiculous project has been going on for nearly two years now. fk fk fk.

 

[mindgames11]

darkened two gears on the left are original. notice how on the bottom face that gear has what's almost an odd bumper around the bearing... so yea- what was stock did not come with needle bearings (that I now have two complete sets of.)
next gear is the first replacement set- aliexpress. pain to get, like 43 bucks.. I can't believe I screwed this up... helical is cut in the wrong direction..
next one is what I got from grin. I was so pleased to just have this crap not in parts form. but of course... that one... is TOO TALL!!!!

background is the motor, with one of the new gears in it (case doesn't close.) I'm thinking about using a nichrome wire and slicing a layer off the top and bottom of the too large gear.. might as well. if I fail to accomplish anything at least I won't have waited in the mail to do it.

another thing, I feel like the gear angle of the two newer gears is shallower than the original, which is cut quite close to vertical. although it's super worn etc. I'm meaning to look up how to measure.
I think I paid $65 bucks for the 20" a2b kuo that came with a battery (one foot in the grave, but still). and I'm over a hundred bucks in for fk***!!!! parts. parts that I don't even want.

I wish there were actually places where you could look up product codes on motors... however the ability to do that is basically zero. I've tried to google hundreds of bike motors I've seen, and only end up coming upon something by accident. and that something of course doesn't have any data that I want.