Help finding a solution to Bafang gear stripping

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jateureka   10 kW

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Re: Help finding a solution to Bafang gear stripping

Post by jateureka » Jun 30 2010 6:49pm

What were the conclusive results of all the testing?
One metal gear and two nylon?
three metal gears?

For a front wheel hub motor s/n BF803D10230 36V 200W, for 26" but mounted in 20", I don't see a model number.
E-bikes: Bafang 8FUN; Mac; Ezee; FreeGo; Aprilia 7s LiPo; eLation V2; TerraTrike recumbent
E-motorbikes: ZEV 7100 LR scooter, 84V 60Ah LiFePO4.
ZERO 2011 S motorcycle, 51.8V 70Ah LiMno2, 2012 headlight, Kilovac EV-200 contactor
E-mower: EGO 56V mower & line trimmer

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docnjoj   100 GW

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Re: Help finding a solution to Bafang gear stripping

Post by docnjoj » Jul 01 2010 8:10am

My newer Bafang has not had any problems at 54 volts in over a year of regular use. Prolly 1500 miles. All nylon gears.
otherDoc
E-bike stable at our house

Steintrike Mad Max full suspension trike rear Cute 100H going on: Whoops, Cute wheel broke but I fixed it.
Sun USX delta trike EbikeKit small geared front wheel sort of front suspension for wife

Agniusm/A123 AMP 20 36 volts on the Steini has been taken off.
2x16000 Multisport from HK now gone as they died after 2 years
New Luna 10S bottle battery 13.6AH now on mine
Relatively New 10S4Px2 for wife's bike giving 20ah @ 40 volts home made Panasonic from Tumich. BMS's rule.

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johnrobholmes   1.21 GW

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Re: Help finding a solution to Bafang gear stripping

Post by johnrobholmes » Jul 01 2010 4:23pm

I think it ultimately depends on the wheel size. If you are riding a 26" wheel, I wouldn't push them more than 12s lipo or 16s life and 20a battery/ 45a phase limiting. On 36v it seems that 25a/ 60a limiting is acceptable. The smaller the wheel, the more power that can be pushed through the plastic gears.

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Russell   10 MW

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Re: Help finding a solution to Bafang gear stripping

Post by Russell » Jul 01 2010 11:47pm

jateureka wrote:What were the conclusive results of all the testing?
One metal gear and two nylon?
three metal gears?

For a front wheel hub motor s/n BF803D10230 36V 200W, for 26" but mounted in 20", I don't see a model number.

I just recently retired my Bafang after over 5,000 miles but it wasn't because of any problems with the original gears. I used the 36V motor at 48V for 80% of those miles with half of that at 15A and the rest at 20A. I do use my motors for assist rather than the prime motive force but I do have hills though nothing very long. Still I have gotten the small geared motors I have run pretty hot from time to time, enough to melt the internal hall wiring insulation on one 24V model running at 48V, but the gears never were a problem for me. My thinking is if you are running the little motors at power levels high enough to puree the gears then the motor itself won't last very long despite switching to metal gears as something else will likely fail. In my experience hall problems on a Bafang are the more common failure mode.

-R
Jeep Comanche Trekking Bike w/YOUE geared motor, 42 lbs + 15 lb rear trunk bag w/12S 16Ah LiPo battery, tools, etc., 21A controller, 700 x 40C tires. 27 MPH.


My other E-Bikes: Nashbar Steel Flatbar

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jateureka   10 kW

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Re: Help finding a solution to Bafang gear stripping

Post by jateureka » Jul 02 2010 8:09pm

Sorry for the poor wording in my first post.

The plastic gears are stripped after about 12 months use. I am looking at alternatives to just replacing with 3 more plastic ones and was wondering if just one metal with two plastic could be a marked improvement.

The motor details:
front wheel hub motor s/n BF803D10230 36V 200W, marked as 26" but mounted in 20" rim for more torque.
This is in a delivery trike that uses 36V LiPo with 15A controller and carries up to 40kg load plus rider. Ambient temperatures can get up around mid to high 30s degrees C.
E-bikes: Bafang 8FUN; Mac; Ezee; FreeGo; Aprilia 7s LiPo; eLation V2; TerraTrike recumbent
E-motorbikes: ZEV 7100 LR scooter, 84V 60Ah LiFePO4.
ZERO 2011 S motorcycle, 51.8V 70Ah LiMno2, 2012 headlight, Kilovac EV-200 contactor
E-mower: EGO 56V mower & line trimmer

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docnjoj   100 GW

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Re: Help finding a solution to Bafang gear stripping

Post by docnjoj » Jul 03 2010 8:08am

I did the 1 steel 2 nylon replacement on my older Bafang and rode it for about 2 years without problems on a 20" wheel. This after peanut buttering the older nylon gears. Only a slight increase in noise level. Worked fine.
otherDoc
E-bike stable at our house

Steintrike Mad Max full suspension trike rear Cute 100H going on: Whoops, Cute wheel broke but I fixed it.
Sun USX delta trike EbikeKit small geared front wheel sort of front suspension for wife

Agniusm/A123 AMP 20 36 volts on the Steini has been taken off.
2x16000 Multisport from HK now gone as they died after 2 years
New Luna 10S bottle battery 13.6AH now on mine
Relatively New 10S4Px2 for wife's bike giving 20ah @ 40 volts home made Panasonic from Tumich. BMS's rule.

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jateureka   10 kW

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Re: Help finding a solution to Bafang gear stripping

Post by jateureka » Jul 04 2010 12:38am

Thanks for the reply otherDoc.
I'm hopeful that one steel planetary gear with two nylon will work for this setup too, although I haven't stripped it down yet to confirm no other damage.
Who did you order your gears from?
E-bikes: Bafang 8FUN; Mac; Ezee; FreeGo; Aprilia 7s LiPo; eLation V2; TerraTrike recumbent
E-motorbikes: ZEV 7100 LR scooter, 84V 60Ah LiFePO4.
ZERO 2011 S motorcycle, 51.8V 70Ah LiMno2, 2012 headlight, Kilovac EV-200 contactor
E-mower: EGO 56V mower & line trimmer

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brumbrum   100 kW

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Re: Help finding a solution to Bafang gear stripping

Post by brumbrum » Apr 21 2011 10:57am

I've just finished reading this 22 page thread and thought i'd bring it back to life. :) has there since been anymore failures with or without the metal gear?
I'm in a similar situation with a Golden Motor '902 prokit' which is geared and rated at 36v 250watt. I have not received the motor yet so have not had chance to take apart. i want to run it with a 54v 20ah lithium-ion pack. What would be a safe cantinuous and peak amp limit? 26" wheel btw.

has anyone had any expereience with the above motor?

Thanks :)
My NYX and cromotor build
viewtopic.php?f=6&t=74615
My LMX 161 dirt bike build
viewtopic.php?f=6&t=94074

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zukster   1 kW

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Re: Help finding a solution to Bafang gear stripping

Post by zukster » Aug 04 2011 12:43pm

Finally after 3 years of use, my son stripped the nylon gears in his rear drive Bafang SWXH 26
Inch wheel model being run by Ecrazyman/keywin 350w/20a Infineon controller and 60V to it.

I had already ordered some metal gears from keywin a couple of years ago (I don't know if keywin
is around anymore), so I just had to install them. One of the nylon gears had actually cracked and
jammed the motor. Not wanting to take anymore chances, I used 3 metal gears.

Its not too loud when the motor has been treated with ACF 50 or fluid film inside to protect it.
See http://www.endless-sphere.com/forums/vi ... 60#p218898

Also a note. The insides of the motor are in good shape, so the above treatment worked and
did its job of protecting the motor though a couple of winters.

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herbie   10 µW

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Re: Help finding a solution to Bafang gear stripping

Post by herbie » Aug 24 2013 7:33pm

Hello guys.
I have the SWXH 36V bafang motor with the 28t gears in the planetary.
They finally went. I built my father of 64 years old a bike using a full size Schwinn Trike.
I bought the motor 4 years ago , but upgraded to a 1Kw on an old ProFlex MTB Bike
Anyway, he finally stripped the gears.
Are there reasonable gears to be had in metal, even aluminum these days?
If not, I obtained a quote from an online custom gear maker, and found I can get them at $3 each without bearing for an order of 100.
Course, I don't need 100, but I did up the cad to drop in a stock bearing.. is there a market for these?
I was thinking aluminum only because it would not melt and be stronger than the Nylon yet weaker than the steel.
I would head the gear in an oven and drop them on the bearing so that even with a hot motor there should be no slippage.
bearings from Stock Drive for these are in the $4-$6 range.

Any help would be great.
Thanks
1,000W 48V on 1993 Proflex Full suspension, 2,000+ Km at 38kph ave. speed. 65kph top speed.
250W 36V Bafang running 48V (350w Total) 2,000+ KM on mtb Bike, 2,000+km on Schwinn Trike Cruizer.

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zukster   1 kW

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Re: Help finding a solution to Bafang gear stripping

Post by zukster » Aug 24 2013 10:15pm

I've done two of the exact same motor. At some point they changed the motor internals so the outside had more or less teeth. I can't quite remember. So I had some metal gears I had bought from Ecrazyman/Keywin years ago. I had to swap parts from an old motor to the new to get it all to work as the new motor that was not burnt out was a bit different.

You must still be able to get the gears somewhere if you know the specs for them. Try to track down Keywin. I've heard that other people on the Forum are still in touch with him. Or even try Banfang to ask for the spec.

The two motors I did with all 3 gears swapped quieted right down after a week and some Fluid Film inside to help break them in. I changed the Fluid Film a few times to get out any metal that may have come off the gears during break-in. After that just a bit in the motor is all that is needed. See

http://endless-sphere.com/forums/viewto ... 50#p218898

where I drill the hole to be able to drain and fill the hub with Fluid Film. I used ACF-50 at first, but it is too thin and I prefer the Fluid Film and you can get it anywhere.

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herbie   10 µW

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Re: Help finding a solution to Bafang gear stripping

Post by herbie » Aug 25 2013 6:41am

Thanks, I know the specs for the gears, 28teeth, 1.25mod, 10mm face width, bearing is 7mm thick with 8mm shaft.
I can do the rest on my lathe, problem is it's damn expensive for metal gears in that odd module.

Stock Drive is $21 per gear then I have to lathe the ID and press in new bearings.
Guy in Germany is selling steel gears for 15euro, same price as the above.
http://www.ebike-solutions.de/de/Shop/M ... 0W-Motoren

At these prices, I'm looking at buying a new motor instead of repairing this one.

now these guys http://www.emachineshop.com/ are quoting
$57.0 for 1
$59.6 for 3
$91.7 for 30
$126.8 for 60

These are in aluminum, so I am thinking of specifying a gear with them, having 30 made up, then ordering 30bearings from SDPI, assembling them and selling alum replacements, or even steel, if there is even a bit of demand for them.
1,000W 48V on 1993 Proflex Full suspension, 2,000+ Km at 38kph ave. speed. 65kph top speed.
250W 36V Bafang running 48V (350w Total) 2,000+ KM on mtb Bike, 2,000+km on Schwinn Trike Cruizer.

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herbie   10 µW

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Re: Help finding a solution to Bafang gear stripping

Post by herbie » Aug 25 2013 6:48am

More Specifically the motor says on it

SuzhouBafang Motor Co. BF801D12324
1,000W 48V on 1993 Proflex Full suspension, 2,000+ Km at 38kph ave. speed. 65kph top speed.
250W 36V Bafang running 48V (350w Total) 2,000+ KM on mtb Bike, 2,000+km on Schwinn Trike Cruizer.

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zukster   1 kW

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Re: Help finding a solution to Bafang gear stripping

Post by zukster » Aug 25 2013 10:47am

Just for your reference, my gear Keywin order looked like this in May, 2009

Keywin Ge ecrazyman@gmail.com

item description:
1 - Bafang 26 Inch SWXH Motor 170 usd
6 - metal gears 45 usd
3 - nylon gears 15 usd
1 - sensorless controller 36v/350w set up as you recommend below. 38 usd

So he was changing 9 per metal gear as a price comparison for you.

Also, the extra reliability of upgrading the gears to metal is worth the extra cost I think. I even had a problem with one run at 48v. It did make it 3 years however.

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