Help with this rear bafang bpm

[nickgeneric]

Hello I have been loitering on this group for a while - thanks to those who have already inadvertently helped me!

I recently bought the motor below - see photo - (think it's a bpm rated at 250 36v) it's up and working fine. However regardless of the top speed settings In the LCD (ktlcd3) I can not achieve assistance above 23kph.
Battery is a 36v 13ah. The settings advised were p1 87 and p2 1.

I was assuming I should be able to get more speed

out of the motor? Does anyone have any suggestions.

Thanks all in advance.
Nick.


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[anotherkiwi]

What is your max speed set to in the LCD? What size wheel is that? How much do you and your bike weigh?

 

[Woosh]

your motor is too small to be a BPM.

This is the size of a BPM laced to a 26" wheel:

 

[nickgeneric]

What is your max speed set to in the LCD? What size wheel is that? How much do you and your bike weigh?

LCD is 34 but caps out at 23. 26 wheels and set as such. Total weight 100kg.

Nick.


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[Nealh]

Assuming you have a KT controller are there a pair of white wires connected together ?
If so it is speed limited, disconnect them to get 30% more speed up to 19/20mph for 201rpm and more for a faster wound hub.
Looks like a 120mm SWX hub.

P1 & P2 are same as my settings for KT LCD.
How about P3 - P5.

 

[nickgeneric]

your motor is too small to be a BPM.

This is the size of a BPM laced to a 26" wheel:

Umm... thanks do you or someone else on here know what it is?


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[Nealh]

Bafang SWXH 120mm hub.

 

[nickgeneric]

Bafang SWXH 120mm hub.

Thanks, slightly disappointing as that's not how it was sold.

Do you know if there are "versions" of this one. By chance are you able to confirm the p1 and 2 settings?

Thanks to all for the help so far.

Nick.


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[anotherkiwi]

Ahem...

https://etrike.wordpress.com/2013/07/06/bafang-swxh-with-steel-planetary-gears-a-short-summary/

68 km/h at 90 V with steel gears in a trike...

 

[nickgeneric]

Assuming you have a KT controller are there a pair of white wires connected together ?
If so it is speed limited, disconnect them to get 30% more speed up to 19/20mph for 201rpm and more for a faster wound hub.
Looks like a 120mm SWX hub.

P1 & P2 are same as my settings for KT LCD.
How about P3 - P5.

Hi Nealh. Thanks this post came in my timeline after the other one!

Assuming the 120 refers to the installation widths it can't be as it's definitely a 135... it's in the rear wheel with a cassette rather than freewheel fitting.

Cheers

Nick.

 

[Woosh]

Assuming the 120 refers to the installation widths

120mm is the approximate diameter of the motor shell.
Those motors fit 135mm rear dropout.

 

[nickgeneric]

120mm is the approximate diameter of the motor shell.
Those motors fit 135mm rear dropout.

Thanks Woosh! I still clearly have a lot to learn. Shame the bafang website does not name them in the same way! .


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[Woosh]

Shame the bafang website does not name them in the same way!

the bafang website only promotes the newest models.
I don't know if we should blame them.

 

[nickgeneric]

the bafang website only promotes the newest models.
I don't know if we should blame them.

I would agree blame is too much! But an old products archive would be a good idea (I will look for one this evening).


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[Nealh]

Motor rpm will dictate speed along with voltage.
A 201 rpm will get up to 19mph a 328 rpm up to 27mph at 36v, more at 48v and as above in AK's link even faster with mods.
Controllers also dictate the speed via their programming, some will have the speed link connection some won't.
135mm is a std width for rear geared hubs, the exception being Xiongad at 145mm. Also a new range of wider hubs for fat bike. Diameters are usually 120mm or 180mm though newer models of about 160mm are appearing.

 

[nickgeneric]

Thanks Nealh very helpful - I will take a look at the controller this weekend to see if it could be that.

Nick

 

[nickgeneric]

Motor rpm will dictate speed along with voltage.


So opened up the controller in the dolphin this evening. To be honest I am not sure what I am looking at! .

Can anyone tell me if they can tell if it's this can be limiting the speed?

Thanks.
Nick.

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[Nealh]

If by the above you mean you opened the Dolphin battery, then you will not find any help in there !!!
The controller is in metal box unless of course it is integrated at the base of the batter, follow the motor wire it will go to the controller.

 

[Deleted member 4366]

Let's go right back to start. You should only measure speed with the wheel off the ground, so charge the battery right up, then measure the speed. That's the actual maximum speed of the motor.

Go for a ride until your battery goes right down. Before charging the battery, check the speed again. If the speed is identical to the previous test, the controller is limiting the speed. If it's slower than the previous test, the motor is limiting the speed.

When you come back with the speed measurement results, we can advise you how to improve it. Don't waste your time doing anything else.

 

[nickgeneric]

Let's go right back to start. You should only measure speed with the wheel off the ground, so charge the battery right up, then measure the speed. That's the actual maximum speed of the motor.

Go for a ride until your battery goes right down. Before charging the battery, check the speed again. If the speed is identical to the previous test, the controller is limiting the speed. If it's slower than the previous test, the motor is limiting the speed.

When you come back with the speed measurement results, we can advise you how to improve it. Don't waste your time doing anything else.

Good point thanks. Speed at full charge is 24 kph now to run the battery down......


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