Bafang BPM II

General Discussion about electric bicycles.
Scottyf   100 W

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Re: Bafang BPM II

Post by Scottyf » Feb 10 2012 6:25am

full-throttle wrote:Link? Would be interested to know who these 'most' people are.
Seals are ok, better than any other hub motor I know of. If you watch carefully Justin's presentation you will realise that seals are not a problem.
The axle support on the RHS is poorly designed - mine snapped.. when hit by a car at 80kph.
I'll dig out the link. But its over on the UK forum on Pedelecs. There are two other users excluding myself that have had the clutch lock up and had to free it. D8veh and Catsnapper.
Jay-UK had the axel snap after 500 miles - Also on Pedelecs. He swapped to a Mac becasue of the issue from Cell_man.

I don't want to argue with you on the topic of what is good and bad, you've been very helpful in the repair of mine and without your posts I would have been off road much longer.

I'm really not slating the motor at all. As I've said its a very very motor. For the cost when I brought it of £150 in a wheel delivered to the UK. Hideously cheap.
The seals are not that much of a problem but could be better. I will look at getting a few more for a replacements. Apart from the material or using a fabric / cardboard gasket it won't ever get much better. Its always the same with Rubber O ring gaskets. Or for any gasket. Onces the pressure is gone they deform and no longer seal as well.

I'm glad Bafang are progressing the motors and fixing some of the issues as outlined by Cwah.
Marin kentfield FS - Unassisted

SoSauty   1 kW

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Re: Bafang BPM II

Post by SoSauty » Feb 15 2012 11:10pm

Yes, I heard the same. I sorta remember a 'You Tube' that showed V1, V2, and V3 of the BMC (not BMS). V1 stated that the freewheel or clutch sorta dragged. V2 was to correct that but the brazing on the clutch would come undone. At last V3 skipped a clip washer to make room for the slightly wider gears, made 'em of composite, corrected the clutch flaw and used an improved freewheel bearing.

Seems these climbers are either a very similiar motor to BMC or a slightly smaller version. Wonder if this latest version of BaFang Climber uses composite gears? Would be cool if you could get a $139 motor with quality freewheeling and composite gears, but I wouldn't count on it.

Be very careful ordering from BMSBattery. They won't take a motor I just ordered back, even if I eat the overpriced return shipping. In fact, DHL said their return address was bogus and they refuse to provide me with a return address. I find the special tool cover unacceptable. I will resort to my VISA card to gain a refund as PayPal is not stepping up.

This motor has 4 radii channels in the cover. (Unseen side) The 8Fun motor has 6 Phillips screws. They are not the same motor (cover).

If anyone has a return address for BMSBattery, please send me a PM. To get my $139 refund has gotten to be a matter of principal.
Attachments
S7301101.JPG
Damaged BaFang 2/9 with problem cover
S7301101.JPG (132.11 KiB) Viewed 3723 times
Last edited by SoSauty on Feb 16 2012 12:06am, edited 3 times in total.
http://www.ebikes.ca/index.shtml No.#1 Trusted E-bike online sales!
3 hardtail MTBs:
-48V Lith-ion 10.5amp hr-408 C-lyte
-BPM 8FUN[*STOLEN]
-run Century rides w/Q100 mini
3 folders:
-20" wife's BaFang,
-20" TurnigyMax50cc airline suitcase folder,
-24" Stewart/Hass 9C; 3.5K/40mph fun racer

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full-throttle   10 MW

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Re: Bafang BPM II

Post by full-throttle » Feb 15 2012 11:17pm

SoSauty wrote:Yes, I heard the same. I sorta remember a 'You Tube' that showed V1, V2, and V3 of the BMS. V1 stated that the freewheel or clutch sorta dragged. V2 was to correct that but the brazing on the clutch would come undone. At last V3 skipped a clip washer to make room for the slightly wider gears, made 'em of composite, corrected the clutch flaw and used an improved freewheel bearing.

Seems these climbers are either a very similiar motor to BMS or a slightly smaller version. Wonder if this latest version of BaFang Climber uses composite gears? Would be cool if you could get a $139 motor with quality freewheeling and composite gears, but I wouldn't count on it.
Do you mean BMC V1, V2 and V3?

Haste   100 W

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Re: Bafang BPM II

Post by Haste » Feb 15 2012 11:58pm

SoSauty wrote:Yes, I heard the same. I sorta remember a 'You Tube' that showed V1, V2, and V3 of the BMC (not BMS). V1 stated that the freewheel or clutch sorta dragged. V2 was to correct that but the brazing on the clutch would come undone. At last V3 skipped a clip washer to make room for the slightly wider gears, made 'em of composite, corrected the clutch flaw and used an improved freewheel bearing.

Seems these climbers are either a very similiar motor to BMC or a slightly smaller version. Wonder if this latest version of BaFang Climber uses composite gears? Would be cool if you could get a $139 motor with quality freewheeling and composite gears, but I wouldn't count on it.

Be very careful ordering from BMSBattery. They won't take a motor I just ordered back, even if I eat the overpriced return shipping. In fact, DHL said their return address was bogus and they refuse to provide me with a return address or a phone number. I find the special tool cover unacceptable. I will resort to my VISA card to gain a refund as PayPal is not stepping up.

This motor has 4 radii channels in the cover. (Unseen side) The 8Fun motor has 6 Phillips screws. They are not the same motor.

If anyone has a return address for BMSBattery, please send me a PM. To get my $139 refund has gotten to be a matter of principal.
wow thats terrible. Mine was in perfect shape and going strong, with 15s lipo I SHOULD be hitting 35s easy, way more downhill of course.

Just gotta fab up something to open the threaded cover, no biggy.

Either way thats terrible on the return address. Ask them if you can get just the motor cover and you can reuse all the guts, either way its 139 dollars.

Also this motor is the bafang bpm 2, the 8fun is bpm 1. Seems like im only one having luck?
1997 Marin Hill Hawk. Bafang BPM 2 10T. KU123 30 amp controller. 12s LiPo.=32mph

SoSauty   1 kW

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Re: Bafang BPM II

Post by SoSauty » Feb 16 2012 12:15am

Interesting, wonder if I should hang on to the motor. DHL is dropping it back off. I loved my BPM I. Yeah, made a tool for the Baby BaFang that worked. Maybe I'll crack the BPMII open when it returns to me Friday. If the gears are composite, I'll clomb on to it. Otherwise my VISA will give 'em 45days to cooperate then retract the charges. Of course, I'll keep things square and not rip them off.

Another off topic tid-bit. Couldn't find 24" juvenile road rims last week. Finally gave in and ordered several CrossCountry style 24" rims. Just now noticed the rims I wanted on BMSBattery site for $7.98 :shock:

I have 19" of 1.5" diameter Torlon laying around and hoped to reverse engineer/machine some heat resistant gears for the BPM II. Could make a neat little motor for Enduros and low-power motored-bike races :P
http://www.ebikes.ca/index.shtml No.#1 Trusted E-bike online sales!
3 hardtail MTBs:
-48V Lith-ion 10.5amp hr-408 C-lyte
-BPM 8FUN[*STOLEN]
-run Century rides w/Q100 mini
3 folders:
-20" wife's BaFang,
-20" TurnigyMax50cc airline suitcase folder,
-24" Stewart/Hass 9C; 3.5K/40mph fun racer

miuan   10 kW

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Re: Bafang BPM II

Post by miuan » Feb 16 2012 2:11am

sosauty: I testrode mine yesterday. What a smooth and silent motor. I'd definitely keep it, unless you plan to go 1.5-2kW continuous at low speeds.

cwah   10 GW

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Re: Bafang BPM II

Post by cwah » Feb 16 2012 3:43am

How come some of you have the bafang 2 from bmsbattery? I asked them and they say they'll have it in a month and it's not available on there site.
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz

miuan   10 kW

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Re: Bafang BPM II

Post by miuan » Feb 16 2012 4:19am

cwah wrote:How come some of you have the bafang 2 from bmsbattery? I asked them and they say they'll have it in a month and it's not available on there site.
I've already posted about this.
miuan wrote:Interestingly, the hardware I got with the new style motor was same as the old style, nothing like the pic from mr.electric. Maybe I just got the old motor with new covers.
So yes I've got the new style covers and the motor looks exactly as this one
http://www.szbaf.com/product.asp?id=11
But no idea what's so new about it apart from the threaded cover.

miuan   10 kW

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Re: Bafang BPM II

Post by miuan » Sep 26 2012 5:46pm

So I have two bafang bpm2 motors with broken halls. All I can do to keep them running is use the bulky bmsbattery sensorless controllers but I'd truly love to crack them open and replace the pos they used instead of proper hall sensors.
I found a tool in Germany costing 50 eur which is not so little for a... well.. tool!
Has anyone found a less expensive source?

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cruzxia   100 W

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Re: Bafang BPM II

Post by cruzxia » Oct 20 2012 8:54pm

I opened my BPM II yesterday, I can confirm that it is identical to the BPM internally.
I had to make a tool to allow me to unscrew the cover. It unscrews in the normal direction and there are no locking grub screws. The factory did put grease on the threads, but the cover was still quite tight. You definitely need the tool to open it.
The build quality looked good.
:)

miuan   10 kW

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Re: Bafang BPM II

Post by miuan » Oct 21 2012 2:41am

cruzxia wrote:The build quality looked good.
The real issues with by BPMs are halls and freewheel threads breaking off covers. I've had both happen twice already. Where can I source covers? Bafang directly?

chayr   10 mW

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Re: Bafang BPM II

Post by chayr » Jan 20 2013 9:50am

Hi all !

I need to open my bafang but do you find an issue to do properly ?
I can open it with hammer and chisel but I think it is unappropriate 8-)

I want open it because it make a particular noise : https://www.youtube.com/watch?v=akJRZ58WJcE

toniovelo   10 W

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Re: Bafang BPM II

Post by toniovelo » Mar 14 2014 8:56am

Any question about BPM II:

There is 2 versions on BMSbattery, Elifebike, GBK... 350w and 500w is same motor??? It's just the "code" is different with different rpm? Thanks.

d8veh   100 GW

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Re: Bafang BPM II

Post by d8veh » Mar 14 2014 1:10pm

I think thst there's more difference than the rpm. I think that the 350w one cannot take so much current. If you have both versions with the same 30 amp controller, the 350w one gives much less power. This is definitely true of the Bafang CST. I think that the BPM2 is the same.

toniovelo   10 W

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Re: Bafang BPM II

Post by toniovelo » Mar 14 2014 4:13pm

Ok for difference beetween 350 and 500w but the 36v and 48v version are same motor i suppose?

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RonnieBrowen2106   100 W

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Re: Bafang BPM II

Post by RonnieBrowen2106 » May 09 2017 7:20pm

My Bafang motor I ordered gets 285 RPM at 36v and 320 RPM at 48v. Supposedly. I guess that makes it a code 11. Are those any good for use in a 26 inch rim? It is a 36/48v 500w motor that I will be running at 1000w. It will be replacing my Direct Drive motor. My direct drive motor spins at 460 RPM. I am only going to install the geared motor temporarily until I get the other bike ordered and then delivered and assembled.

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motomech   1 GW

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Re: Bafang BPM II

Post by motomech » May 10 2017 1:44am

A code 11 in a 26" wheel on 48V should do 27 to 28 MPH.
A 25 to 30 Amp controller would be in the correct range.
That is a mid/high speed motor and might be a little weak on steeper hills.
Why would you replace it? It's a good motor.
Motomech


'07 GT Idive 4 4.0, Q100H 201 frt. mounted, 14S Multistar LiPoly, elifebike 9-FET 20A controller. Mean Well HLG-320H-54A, Crazy Bobs on Alex DM32's 21 to 22 MPH. viewtopic.php?f=3&t=28151&p=1373714&hilit=Idrive#p13737

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RonnieBrowen2106   100 W

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Re: Bafang BPM II

Post by RonnieBrowen2106 » May 10 2017 7:56am

motomech wrote:A code 11 in a 26" wheel on 48V should do 27 to 28 MPH.
A 25 to 30 Amp controller would be in the correct range.
That is a mid/high speed motor and might be a little weak on steeper hills.
Why would you replace it? It's a good motor.
I am only replacing it for a short time. I will put the other motor back on after a while. I am curious to see what it can do. I am building another bike which the geared motor will stay permanently. But that will not be finished for at least two months. I don't have tons of money at the moment, so the next build will take a long time to complete.

mechhead   10 W

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Re: Bafang BPM II

Post by mechhead » Jan 30 2018 8:24pm

I may have found another version of the bafang bpm that claims 0.35mm lams and curved magnets on alibaba unless they are lying, here is the link anyway I'm currently communicating with the seller about getting one sent to australia for conversion on my FS bike, I was looking at an rc drive but this modification of a hub to mid drive (crossbreak style) is so much simpler.

here is the alibaba link https://www.alibaba.com/product-detail/ ... c049j33pPo

They include pics of their motor internals on the page.

another thought I had is about the failure of the nylon gears, I suspect this is likely from high power levels being applied when the nylon is too hot. Have any of you played with the replacement steel gears that are available ?

mechhead   10 W

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Re: Bafang BPM II

Post by mechhead » Jan 30 2018 8:25pm

This version has the 6 screw casing available with front wheel configuration or rear with screw thread freewheel mount or casset and comes in 4 different winds the available specs are:

9x 11 turn 260rpm @36v
10x 10 turn 280rpm @36v
11x 9 turn 305rpm @36v
12x 8 turn 336rpm @36v

I presume the first spec number ??x designates number of strands its wound with, all using multiple strands of the same wire.

I'm going to order one once I work out which winding spec to go for, it claims to have the 0.35mm lams as well .

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