Help finding a solution to Bafang gear stripping

[spike]

what controller-limit (amps) do you use ?

I was using the e-crazyman 48v 30A controller http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300248682281. The batts are good up to 60A but the controller won't let them go there (I think).

[recumbent]

These motors clearely cannot handle E-bike loads and should be classified for toy use only

After reading about many "Bafang"gear hub failures, and owning a quality geared hub motor for 5 years without any failures what-so-ever, the term "you get what you pay for" holds very true with respect to geared hub motors.

[Kraeuterbutter]

@recumbent:

These motors clearely cannot handle E-bike loads and should be classified for toy use only

i would not aggree with that at all
its totaly unfair

the Bafangs are rated for
24V and/or 36V ====> spike powered it with 48V

the Bafangs are rated for
5,5A to 12,5A (depending on motor-model) ====> spike was using a 30A limit-controller

the Bafangs are rated for
150Watt, 180Watt, 200Watt, 250Watt
(depending on modell) ========> spike was using up to (45V * 30A) = 1300Watt


iam using a 24V Bafang, rated for 180Watt and 12A

i use it with an 14A controller and 36V Battery, seeing this way up to ~500Watt

so iam too going over the rated limit.. sofar - 1200km up and down many hills and going offroad - it works very well and fine

i think, when you use it in the way it was designed for/made for, you will not face any problems

[voicecoils]

first few km of testing with 'heavy metal bafang'

no failures, will continue to test and then do a visual inspection and re-grease perhaps at the 50km mark or so.

Details and a photo here:
viewtopic.php?f=6&t=4925&p=124098#p124098

Still some life in the inexpensive bafang yet I hope

Would like to have a go on the nice German Heinzmann at some point. They only do brushed 36v hubmotors through, right?

[Kraeuterbutter]

a nice clean setup you have there..

for the Heinzmann: they have geared and gearless, brushed and brushless motors

for my use: (and i "only" power the bike twice as much as is allowed here in europe)
the Heinzmann would be

1.) too expensive
2.) too heavy (for 200W average and 500W peak i see with my 14A controller)
3.) too noisy
4.) too big from optical standpoint

of course, when you plan to power your bike up to 1000Watt and even more, than you need a motor which is bullet proof

when you build a bike within the laws (at least within the european laws) or break the (european laws) only by factor 2
then the bafang is the better solution, because
1.) cheaper
2.) smaller
3.) lighter
4.) more quiet

[spike]

Re Recumbents/Kraeuterbutters comments. Keywin told me before I bought the motor that it was only rated at 250W. However, the motor was cheap and I was happy to over volt it and take the risk. I guess if I'd stuck to the rated volts/amps it would still be going, but 250W in a hub isn't enough useful assistance (for me anyway). I'm not knocking the Bafangs, Keywin, or Knuckles. Just letting people know what happened. The metal gears should fix it, but then there's the noise issue

[Kraeuterbutter]

I'm not knocking the Bafangs

i know..

but recumbent said:

These motors clearely cannot handle E-bike loads and should be classified for toy use only

thats not true..
for the purpose they are made, they work preety well...

( mine, with power at 600Watt: http://www.youtube.com/watch?v=3TQZqctp-gY running twice as fast as it is allowed in europe and the EU, and even more than twice as fast than it is allowed in austria)

as long as you stay at the legal speeds you will not see problems

its like overclocking a 3 GHZ Pentium to 6-9GHZ and when it fails to say: "Pentiums are toys, not useable as desktop-PCs"

i only wanted to state, that there is no problem with the bafangs in the way they are made for and sold for

so: lets say: "the bafang is not the best motor for overvolting and using controllers with lot of amps"
and not say: the bafang cannnot handle e-bike loads, is a toy... --> thats wrong

[mer]

Just an update ...

my Bafang ( which has 8FUN engraved onto it , 250w 36v model ) still works great at 48V with the 30A ecrazyman controller with lifepo4 batteries . I suspest I have done more than 300 kms ( probably more ) and I still accelerate from the steepest hills ( from a dead stop ) and I have tried ( and still trying ) almost everything to get them into peanut butter state but I didn't have any *luck* lol . I hardly pedal .

Lots of fun

[recumbent]

I think i hit on a sensitive issue , but when you work in industry for many years as i have, electric motors are seen as reliable and maintenance free. One of you fellows said he rode his Bafag for 300km, that's only two weeks operation.

I never meant to put down your precious little motors, I just have different expectations, and reliability is an absolute, or it's not worth buying.

My bike has to carry a 190lb man, 20lbs of batteries for range, and 45lbs of bike bits and cargo, then ride for two hours without issue, every day, and that's exactly what these gearless hubs do.
The bigger geared hubs have an excellent torque curve and i'm tempted to buy one, once they prove reliable which i think they already have with seasonal greasings.

Wish you luck with the steel gears though, and no hard feelings. We all learn from your tests.

[Kraeuterbutter]

Hi recumbent,

i hope you don´t think iam a little child who is angry because you slam about my bafang, and now iam froward
for overvolting and over-ampering setups there are for sure more robust motors and of course: on a gearless motor there are less parts that can go wrong

i only wanted to state, that a bafang - used in the way it was designed for - is not useless for e-bikes..
here in Autria is a importeur who sells the geared bafangs to single persons and to companies, and he said in the forums,
that he had no bafang with failed gears sofar, and he has sold over 1500 units..
he works close with the manufactor, he visits them regulary in there factory

BUT: here in europe the motors are used with 24Volt and for power with 36Volt
there are only few people who are "nuts", and power them with even 48Volt and 15A controller...

well.. this gear-stripping-problem is a US-problem, you see only in US-Forums...
(72V tunings (more than 50Volt is not allowed in europe because the law says, that it starts to become life-dangerous over 50V), or controllers with 30A)

so: 72V, 30A ==> there are no such bikes here
(hell, the most sold bike here are the Swiss Flyers (Panasonic drive) with 250Watt)

oh: he also said, that the gears should hold longer than the free-wheel-unit, the free-wheel unit fails first...
it should be replaced after 30.000km

so, my 1200km are maybe not significant,
but at least: in the German Pedelec-forum are some using the bafang, with some tousands of km and i have not read of one gear-failure sofar

[spike]

Wish you luck with the steel gears though, and no hard feelings. We all learn from your tests.

I've ordered a mix of steel gears and nylon gears from Keywin. I'll try two nylon with one steel first. If that fails, then two steel with one nylon. All steel being the fallback option. I don't like gear noise so I'm hoping I'll only need one steel gear. I'll post back when/if I've there's anything worth reporting.

Cheers

[Knuckles]

I am enjoying this thread ...

The Bafang weighs 3 kgs. It is a small diameter motor. Cost (motor only) under $200 (delivered).
The PUMA weighs almost 5 kgs. It is a larger diameter motor. Cost (motor only) under $500 (delivered).

The Bafang gear ratio: 4.3:1 - has internal freewheel.
The PUMA gear ratio: 5:1 - has internal freewheel.

I run BOTH these motors at 72V nominal.
BUT ... I use a steel gear as MANDATORY!
The noise increase with 1-Metal gear is minimal.

I am over 200+ lbs. Steel diamond frame ebikes. NiMH batteries. On and Off road testing.
The Bafang (w/ 1-Metal gear) w/ 72V30A Infineon - Top Speed on flat 28 MPH. It will get very warm.
The PUMA (w/ 1-Metal gear) w/ 72V50A Infineon - Top Speed on flat 32 MPH. It will get mildly warm.

The Bafang (w/ 1-Metal gear) w/ 72V30A Infineon - Better startup torque than my Direct Drive motors.
The PUMA (w/ 1-Metal gear) w/ 72V50A Infineon - INSANE startup torque. A real BEAST!

PS ... I LOVE MY TOYS! Fast and Powerful!

My_Bafang_2.jpg (73.33 KiB) Viewed 1325 times

My_PUMA.jpg (119.2 KiB) Viewed 1323 times

These motors clearely cannot handle E-bike loads and should be classified for toy use only.

WRONG!

[linear]

I am enjoying this thread ...

The Bafang weighs 3 kgs. It is a small diameter motor. Cost (motor only) under $200 (delivered).

Where do I find this price?

[voicecoils]

I am enjoying this thread ...

The Bafang weighs 3 kgs. It is a small diameter motor. Cost (motor only) under $200 (delivered).

Where do I find this price?

PM Knuckles

Or email 'keywin' ecrazyman ATT gmail DOT com if you're not in the USA

[Knuckles]

Contact Keywin ... ecrazyman@gmail.com

You can cc me also rnich01@optonline.net as "helper" to make sure Keywin understands your request.

[docnjoj]

I agree about the low noise level with 1 steel and 2 nylon gears on the Bafang. It sounds about the same as the all nylon motor! More testing (by me) needed but initial results are promising. I am VERY sound sensitive!
otherDoc

[MotorSmoke]

I don't own a bafang motor, but I do desire one. After much reading on this forum, and particular about
this motor, it occurs to me if one drills some holes around the outside body of the motor, it would allow a lot
of cooling that does not otherwise happen very well. This may solve two problems, both the melting gears and
allow extended high power operation; after all, electric motors are mainly limited by the ability to get rid of heat.
I would think that unless one uses it in very dirty conditions holes would be just fine. Water would be continue to be
flug off the motor and would hardly get inside during use, and the holes drain during a rain.

Just some thoughts.

[zukster]

I just followed this thread from start to end - whew!

I noticed that its been a general observation that a 26 inch specified bafang in a smaller
wheel does not tend to wear the gears as bad.

I just wanted to point out that some of the Bafangs come for a 28 inch wheel. This may
give similar results in a 26 inch wheel, albeit only a few percent improvement.

http://www.szbaf.com/en/Product.asp?CategoryID=275

[docnjoj]

After about 200 more miles the Bafang is still fine. I am avoiding taking it apart for regreasing cause Im lazy!
otherDoc

[zukster]

I just wanted to post a follow up here because I bought a whole bunch of metal and nylon
gears from keywin about 6 months ago, but I've never had to use them. I originally bought
them because I was getting the motor too hot when running it with the 2nd size up
Infineon controller 30a/600w jobby. Ended up smoking the motor and melting the gears
a bit running it with 40v and 60v Can Tire Yardworks battery packs.

I ended up buying a new motor and switching back to the 20a/350w little controller.

I've been running this now at 40v and 60v for over six months now without any problems
at all, pulling a trailer + 5 year old + car parts + much ruthless hill torture (to really test it)

Its really quick at 60v. Should be plenty of power for most people.

If you're looking for a safe setup without overheating the motor or controller, I'd say
don't try to push it more than the above. I was even too lazy to use a fuse and have
not had any problems. But you really should use a fuse - it might have saved my little
controller a few weeks ago when I accidentally hooked up 4 20v Yardworks batteries
in series = +80v - don't ask. Hopefully I just have to put a new 63v cap in that blew.
But a fuse might have avoided any damage in the first place.

Anyway, no gear problems at all in 6 months at 40v and 60v with the little controller.
Maybe I'll use the gears if I do some maintenance on the motors in a year or two.

edit: I think Keywin is suggesting limiting to 48v battery packs for this controller now.

My posts re opening the Bafangs and other testing were here:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=9969
http://endless-sphere.com/forums/viewtopic.php?f=2&t=10094

[richerson]

Hi all

Just like to report my experience with the bafang, I have a rear one in a26" wheel with 66..6v lipo pack and a 72v 45amp infineon controler. I live in London and ride 12-20 miles most days and have just clocked up 1000miles. No problems so far, doesn,t overheat, but it is a bit more noisy know. Lots of stop start riding but mostly flat terain. This little motor is awsome.

[zukster]

Hi all

Just like to report my experience with the bafang, I have a rear one in a26" wheel with 66..6v lipo pack and a 72v 45amp infineon controler. I live in London and ride 12-20 miles most days and have just clocked up 1000miles. No problems so far, doesn,t overheat, but it is a bit more noisy know. Lots of stop start riding but mostly flat terain. This little motor is awsome.

I had a similar setup with a 30amp controller and a 60v battery pack. And I burnt out the motor. It was most likely from
my batteries sagging, but yah, sounds like 1000 miles should be enough to tell.

Nice to know the Bafang works at 66.6v reliably if the setup is done right.

[Russell]

Hi all

Just like to report my experience with the bafang, I have a rear one in a26" wheel with 66..6v lipo pack and a 72v 45amp infineon controler. I live in London and ride 12-20 miles most days and have just clocked up 1000miles. No problems so far, doesn,t overheat, but it is a bit more noisy know. Lots of stop start riding but mostly flat terain. This little motor is awsome.

Interesting,but I think the flat terrain is what really helps keep your Bafang from melting. BTW, what model Bafang do you have? Do you have a wattmeter on your bike to see how much power you're actually pulling? What is your average and top speed on a normal trip?

By comparison I'm pretty easy on my Bafang running it at 48V with a 15A controller but I still can heat it up pretty good with sustained speeds over 20 mph (32 kph). So far I have over 2,700 miles on mine and hope to put on many more.

Hmmm...maybe that famous London fog effectively wicks the heat away from your motor and keeps it exceptionally cool

-R

[zukster]

By comparison I'm pretty easy on my Bafang running it at 48V with a 15A controller but I still can heat it up pretty good with sustained speeds over 20 mph (32 kph).

I go a bit more than that. 15a and 60v and lots of hills, trailer, 5 yr old. I can get it warm with 10-20 minutes
of sustained abuse, but not hot like when the other one burned up. By warm I mean the motor or controlled
won't cause you to pull your hand away when you touch them.

I'm sure the flats help at the higher amps and volts. Try some big hills if you can find some and let us know.

[richerson]

Hi

I don't have a watt meter on this setup, top speed is 27mph off the charger then settles down to 24mph after a couple of miles. Doesn't take many seconds to get to top speed but probably only keep top speed sustained no more than 2-4 miles as there is lots of trafic here. I would of thought starting off the lights would heat it up more than cruising at top speed?