Replacement "guts" for geared hub motor

Joined
Jun 25, 2022
Messages
50
Hello ES!

I am a 1 year old small eBike repair shop (eastern PA) and still learning SOOOO much. Cheap internet eBikes are not easy to repair! Hey JUSTIN, can I come over and look over people's shoulders for a few weeks? I'm learning EVERYTHING on the fly and would love to have some wisdom/old timer experience. Each repair is a rabbit hole of unknown incompatibility!

I have a Nacto Cruiser geared rear hub motor (48v 500W) that is burned to a crisp! I had to leave it outside after taking it apart, IT SMELLS! Yuck!

My client purchased this POS (piece of s**t) from a guy for $200 and is hoping for a miracle. Its the same old story, buy broken stuff and hope it can be repaired dirt cheap, ride into the sunset with "magical" value realized! The poverty sob story is part of the charm!

I'm searching for the supplier that can get me replacement guts? (26 x 4 Fat tire)

Replacement parts is difficult in general, its a wild west of cheap stuff.

I could just buy the whole new motor laced into a rim but am hoping to replace only broken parts. A whole new motor laced into a rim is more expensive right?

This part from AliExpress is close but my burnt motor has a cable the exits before the threaded part of the axle. (not at the end)

The bike dropouts measure at 183mm, and the "shoulders" of the motor axle measure 176mm. I assume the two (3.5mm)"torque" washers fill the 7mm difference.

Rotor diameter: 118mm
Stator width: 42mm
Nylon gear teeth: 36T
Nylon gear height:13.6mm
Nylon gear diameter: 47.8mm
Shaft screw: M12 with 10mm flat
Main shaft diameter: Clutch side 15mm, cable side 17mm
Clutch diameter: 88mm
Clutch height: 10mm
Connector: 9 pin waterproof with bullet extension

Please tell me I'm crazy to do this rabbit hole work eh? I'm hoping to make a living...argh!
 

Attachments

  • Burnt motor clutch.jpg
    Burnt motor clutch.jpg
    849.6 KB · Views: 15
  • burnt motor empty hub.jpg
    burnt motor empty hub.jpg
    805.1 KB · Views: 15
  • Burnt motor PCB.jpg
    Burnt motor PCB.jpg
    880 KB · Views: 15
  • Burnt motor side view.jpg
    Burnt motor side view.jpg
    847.7 KB · Views: 14
  • Burnt motor top view.jpg
    Burnt motor top view.jpg
    785.1 KB · Views: 12
Best thing you can do is order an exact copy of the motor and swap the core.

Don't expect any degree of interchangeability in motor cores from one motor to another. There is no standardization at all. There is also a small change that the motor itself has changed over the years.

If you can't get an exact copy then i don't recommend attempting a swap at all, otherwise it would be easy to lose money on this job ordering some odd part from China with no possibility of a return.
 
Thank you Neptronix,

I'm losing/investing the money and time as I wonder from one rabbit hole to the next. I'm extremely lucky that my wife pays the bills while I work on getting in the air (launching). I'm like a large soaring bird trying to get off the ground, clumsy frantic running and no elevation!

I hear you on the sunk cost/benefit analysis.

Yes an "exact copy" would be great but how to ID this thing? This motor has the "oval" stamped on the outside but otherwise I'm unable to identify it. I suspect it's a white label Bafang.
 
TBH you are in a tough business to begin with. The alibaba special bike customer rarely has the money to repair the bike, and your parts suppliers are usually a pain in the ass. You'll have to be extremely clever to succeed, as well as be able to shoulder the R&D costs to get off the ground per se.

The contents of the oval would be a good idea to google search. You could also reverse image search the logo ( i think google can do this? or other services can ) to find the original supplier.. Or you can contact the ebike maker if they still exist.
 
The company that makes the cheap Chinese ebike I started with will accept an invoice and a parts request, make a link on their site, and you can then buy a replacement. I'd charge the cost of that plus something like $60/hour labor on top. Charge for parts upfront, labor after. If customer won't pay, don't take the job.

If just building for yourself, easy to get a bunch of cheap broken bikes off Facebook and mix and match parts. That's at the whole motor/wheel level, though. Not motor internals. Heck, I still have a Bionx motor, wheel, battery, and charger I got for free that way I haven't shoved on a bike yet.
 
Thank you Neptronix,

I'm losing/investing the money and time as I wonder from one rabbit hole to the next. I'm extremely lucky that my wife pays the bills while I work on getting in the air (launching). I'm like a large soaring bird trying to get off the ground, clumsy frantic running and no elevation!

I hear you on the sunk cost/benefit analysis.

Yes an "exact copy" would be great but how to ID this thing? This motor has the "oval" stamped on the outside but otherwise I'm unable to identify it. I suspect it's a white label Bafang.
There're some local bike shops doing two things that doesn't exactly compete but maybe can be combined.

Fika and service n repairs. Or to say Coffe and bun + service. An hangout and social place - add a sofa? I wish I had one in my shop.

Generally it will not be a big profit on cheapskates and an easy rule is to name your price and start high (salesman tactic) and then go down in price as you give them options. Also not mentioning a repair of a sort that adds risk to you because usually it will go wrong although any good intentions is 100%. So many times I tried to screw in a screw and stuffs brake when you try to be helpful simply tightening a bell or anything alike.
 
I'm losing/investing the money and time as I wonder from one rabbit hole to the next. I'm extremely lucky that my wife pays the bills while I work on getting in the air (launching). I'm like a large soaring bird trying to get off the ground, clumsy frantic running and no elevation!
It will be good practice delivering the bad news to the client that it can't be fixed at a reasonable price; and a lesson learned for next time about when to cut your losses. Good thing having a sugar mama.
 
I just checked your website and the idea to disassemble and "salvage" an old ebike for parts was pretty cool. hehe

Take service fee, hour and start.

Give customer all parts and cash in. We could take 150 for that I guess. No need to save all parts. Some may be broken. No pay gives right to imbune items( take all bike parts as payment)

Same with testing. We take 20 or 50.

Putting on an ebike system 250
Putting on motor or battery 150

The cheapest service I would say to put on an ebike system is 100 but we don't do that low.
 
Thank you everyone. I appreciate the gut check and advice.

This thread turned into a business consultation for me, I'm grateful. I'll start a new thread about this in EV Business World under "My new eBike shop: Structuring, building, and pricing. Reflections and criticisms please."

I've got a LOT of business oriented musings and questions.
 
That motor sort of looks like a Bafang G60.

Grin Tech carries the G60.

Of course there are probably a gazillion Chinese copies so no telling what will or won't interchange.
 
Back
Top