Golden motor mini hub - off center

[kefa]

I was excited to receive my GM mini motor only 8 days after placing the order. Us guys in Aus living on our island continent aren't use to such fast service so that was pretty impressive.

However I was sorely disappointed after opening the package though - it looks like I got a dud. Can't quite work out exactly what happened here, it looks like the hub casing is for the rear hub motor, but the axle length is correct for a front hub. But I can't use it as a front hub motor as the flanges are not centered and for a rear hub I would need a longer axle and there is no thread for gears. Have sent GM a message and will see what they say. Back to waiting now....

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[Russell]

That IS an odd duck you got there :? , it's way different than the Mini Motor I got from GM. I did have to add a thick washer on the right side to center mine in the front forks but otherwise the flanges were symmetrical.



You could use it on the front if you dished the wheel when you built it but that would be kinda silly. I suggest you copy the boss man at GM ( yaoyuan@goldenmotor.com ) with any correspondence you have with the company to expedite getting a replacement.

-R

 

[kefa]

I've taken some photos with the hub in my front forks. The flanges are way off center.

I spoke to Tom from GM and he is claiming that this is there new front hub as the previous one didn't give enough clearance for the disc brakes. But even so it still doesn't make sense for the flanges to not be centered. I want to use V-brakes so I need the wheel pretty much in the center, which implies I will need to build the wheel with it warped to one side and that seems very unsatisfactory.

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[Russell]

That is completely unacceptable! While dishing a wheel is common practice for a rear wheel there's no reason you should have to do it for the front.

As I said above take your complaint to the the boss at GM. Also join the GM forum and post the pics there as well.

http://goldenmotor.com/SMF/index.php?PHPSESSID=7e4f3b6283a6f64c9c3ec1558bbdcbb9&


-R

 

[kefa]

will do russell.

thanks for the support.

 

[Russell]

My Gm Mini Motor is the same as the original Bafang QSWXH however from the the recently revamped Bafang website http://www.szbaf.com/prolist.aspx they appear to have redesigned it and show just the rear version SWXH (aka Unique).

View attachment Unique.jpg

The casing of the Unique however looks like yours so I'm wondering if they took the rear version and hastily made a front version without thinking it through.


The case for the sensorless QSWXK (aka Jewel) looks like my GM MIni (or the original QSWXH)


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So I think what GM needs to do is try to source a sensored Jewel from Bafang or go back to the QSWXB (aka CheapButGood) for their front Mini Motor though it doesn't support a disc brake.


View attachment CheapButGood.bmp


Did I totally confuse anyone?


-R

 

[Bikemad]

I'm wondering if they took the rear version and hastily made a front version without thinking it through.

I think it's just an unfortunate mistake during assembly in the factory and they've somehow used a rear housing to build the front hub. They've used the correct end cover plate, and axle assembly, but got one rather important piece wrong!
As these parts are assembled by hand, the occasional human error is inevitable.
It's unfortunate that it wasn't noticed before it was packaged and despatched.

See the thread on the GM forum

Russell, did those mini torque arms come with your Bafang as standard?

Alan

 

[kefa]

surely there would some kind of QA or testing that would pick up these errors!??

the GM products do look awfully similar to the bafang motors. it was quite amazing how the core of your mini fitted perfectly into the bafang casing.

 

[Russell]

I think it's just an unfortunate mistake during assembly in the factory and they've somehow used a rear housing to build the front hub. They've used the correct end cover plate, and axle assembly, but got one rather important piece wrong!
As these parts are assembled by hand, the occasional human error is inevitable.
It's unfortunate that it wasn't noticed before it was packaged and despatched.

See the thread on the GM forum

Russell, did those mini torque arms come with your Bafang as standard?

Alan

A good theory but I see no one from GM has chimed in yet on the GM forum about the motor.

The mini torque arms I'm using on my GM Mini Motor are from a Nine Continent kit.

-R

 

[kefa]

seeing GM aren't being very helpful - i decided to pop the hub open and check out the core and see if bikemad's theory was plausible.

from what i can see it looks very similar to the bafang and original mini, might be possible to swap the core into one of those front hub cases? anybody got a dead mini or bafang they could give me? otherwise i might just have to lace up the wheel dished.

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[ktronik]

Hey guys,

99% of all disk hubs have off-center flanges, on MTBs, thus need to be dished to one side. no matter front or rear...so its standard in the bike world...

Ktronik

 

[Russell]

Hey guys,

99% of all disk hubs have off-center flanges, on MTBs, thus need to be dished to one side. no matter front or rear...so its standard in the bike world...

Ktronik

Hey you're right about that, conventional disc front hubs DO have different left and right flange offsets of from 10 to 20mm for the ones I looked at however if you look at the photos of the motor in question you'll see that the flange offset in no way is the result of making room for the disk mount. Take a look at the following comparisons between Kefa's motor and my GM Mini Motor.


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The new motor may give some extra clearance for the disc caliper but it sure doesn't add any for the disc itself. I still contend the new motor Kefa has is in error and there is no reason for the sides to be that asymmetrical. I sure wouldn't want a motor like that.


-R

 

[ktronik]

Hey,

I am a bit of a newbie with e-bikes but have been a bike mechanic for 20 years & currently work as the head mechanic for a bike shop. From past experience in trying to fit disk brakes to hub motored bikes, its the brake caliper that hits the spoke heads on the flange, that has been the problem for me. From your pic, moving the flange over looks to really help my problem. I build dished wheels every day & would not have a problem building that hub dished, in fact this new hub looks great as it looks like it would work properly with a disk caliper & not hit the spoke heads... so I have ordered one for my Surly KM... for a quick light weight build...

I do however feel you pain, if using v-brakes you should not be forced to use a (dished) disk hub & should be given the option to buy the non-disk version...

If mine comes non dished I will swap ya...

just my 2 cents worth

Ktronik

 

[kefa]

hey ktronik,

yeh let me know what kind of hub you end up receiving. if it looks like russell's, please let me know and we can do a swap.

i've actually ended building up a wheel with it dished. i'll upload some photos when i get the chance. its my first time building a wheel so i hope it holds up alright!

kefa

 

[Kevinator]

hey russell, do you notice any wobble with your GM mini? I just received my rear GM mini and there's some wobble in the hub when I bring it up to speed. Its still unlaced and the wobble looks like enough to cause alignment issues with a disc brake. I think I got one with a bent axle.

 

[Russell]

hey russell, do you notice any wobble with your GM mini? I just received my rear GM mini and there's some wobble in the hub when I bring it up to speed. Its still unlaced and the wobble looks like enough to cause alignment issues with a disc brake. I think I got one with a bent axle.

I have experienced no wobble with mine and I am very particular about the trueness of my wheels.

The first Mini I received from Golden Motor did have a bent and cracked main housing flange so yeah damage is definitely not out of the question. They sent me a new motor but then my problem was easy to show with a photo, yours may not be so easy to prove to them but give it a try. I made sure I sent my complaint to the big boss himself ( yaoyuan@goldenmotor.com ) and I copied him on subsequent emails.

Good luck

-R

 

[Bikemad]

I think I got one with a bent axle.

Kevin,
A bent axle is extremely unlikely, but if it was bent, it could not cause the hub housing to wobble because the axle does not rotate!

Alan