Programming the Bafang Middrive BBS01+BBS02

[amigafan2003]

Only problem for now though is I think DI2 is only available for tight ratio road cluster setups. I beleive 28 tooth is the largest gear you can currently use.

28t is the range, not the max sprocket size. So it should cope with a single front ring and rear 11t-36t fine (as that's a 25t range).

 

[Kepler]

28 tooth I was refering to is the max sprocket size the DI2 could handle due to it being a short cage road Derailleur. Good news is though that there is in fact a medium cage model available that can handle up to an 11-32 cassette. Interesting they say the 11 speed chain is 20% stronger the 10 speed chain. With the 11 speed chain being slightly narrower, wonder if it would work ok on the standard Bafang chainring.

 

[tahustvedt]

Check this out. Ready to use programming cable for the Bafang BBS: http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html

Pricey though.

 

[tomjasz]

Check this out. Ready to use programming cable for the Bafang BBS: http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html

Pricey though.

With our group buy the complete cable set up ran $36 and the adapter can be swapped for $2-$6 if there is a OS problem. $63 and no guarantee is steep.

But the simple ideas shown throughout this thread get it done for $3-$7 on the cheap.

 

[Clobber]

Check this out. Ready to use programming cable for the Bafang BBS: http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html

Pricey though.

Looks "Home Made" by an amateur too!

 

[savaoaknyc]

28 tooth I was refering to is the max sprocket size the DI2 could handle due to it being a short cage road Derailleur. Good news is though that there is in fact a medium cage model available that can handle up to an 11-32 cassette. Interesting they say the 11 speed chain is 20% stronger the 10 speed chain. With the 11 speed chain being slightly narrower, wonder if it would work ok on the standard Bafang chainring.

Yea bosch is working with shimano on this right now for the next wave of pedelecs.
Kepler since you have good experience with the bbs dissasembling etc.., i was wondering , if it might be possible to manufacture new axle in order to accommodate the 92mm BB.All new enduro bikes are coming with 92mm bb and it's just pity, that the bbs could not fit.So is it possible any hack to be done, if you have the tools??

 

[tahustvedt]

Shimano derailleurs will work with bigger cassettes than their own specs as long as the total tensioning range is withing spec. I'm using an 11-32 cassette with a short cage road Ultegra 6600 derailleur with a single front chainring.

 

[speedmd]

Pulled my "new" cable connectors apart last night to get a measure of what exactly they changed. My original c951 / controller link cable connector used a keyed 6 mm diameter (outside of male plastic section) connector. With the latest replacement controller/ c961, I got a non keyed 9.5mm diameter 8 pin (one in center) connector cable. It is molded in with a alignment arrow and a "03" and "bafang" in the outer custom injection molded connector housing. They are asking for trouble not having a key IMO. I was super careful and still had no confidence I was getting good enough alignment to keep from trashing these tiny pins. Looks like it is different than what others are showing. Sorry, I did not take pictures and I will not be pulling it apart again until it is time to program as this is certainly not a good setup for frequent use.

cheers

 

[mclark999]

The PAS system has a certain crank speed for which it will assist, and then drops off once it's programmed crank speed (RPM) is reached. Each time you shift to a higher gear, you suddenly decrease the crank speed. Thus the PAS system picks up again to help with the assist. In the programming you can change the amount of assist relative to the crank speed for a more "natural" feel. The better way to have the PAS provide more assist is not to shift to a higher gear, but to slow down your pedaling and/or increase the PAS level. - Or do like I do and just ride the throttle in 1st gear and clown pedal so you don't get strange looks. 8)

What setting changes the level of assist based on crank speed? Per another post, the Keep Current setting changes level of assist based on road speeed. Is it actually working based on crank speed (cadence)?

I'd like my assist to drop as my cadence picks up.

 

[mclark999]

Stock setting (20A), mine is pulling 1150W.

I haven't changed the main amp limit, just the assist % current limit in each of the assists. So assist setting 9 is set at 70% from memory.

It appears then that the main amp limit may have little or no effect ? and using the level settings is a better option.

I couldn't leave it alone without knowing so I connected the meter again and tested a few different settings in the main amp limit setting. I seems like the setting is 5A less than actual amps on the meter. Which makes sense when these BBS02 750w units are supposed to be 25A, however the software is set to 20A by default.
I've set my software setting down to 13A which on the meter at 100% pulls 18A or 800W.

I don't know if this is the case with all the other models or just specific to the 750W unit.

Is it possible that the "Limited Current" parameter is a limits continuous output and not peak output?

 

[mclark999]

My economy in my own destiny now as I know how much power each assist level is going to give me. The power steps are very uniform and predictable with this setup. Interestingly, 130W is the very lowest assist level I can set. I did have "0" assist at 5% current but it made no difference compared to "0" at 10% current

So the assist Wattages are as follows with this setup (750W BBS02).
Assist 0>>>>>10>>>>>130W
Assist 1>>>>>15>>>>>160W
Assist 2>>>>>20>>>>>200W
Assist 3>>>>>25>>>>>250W
Assist 4>>>>>30>>>>>300W
Assist 5>>>>>40>>>>>400W
Assist 6>>>>>55>>>>>550W
Assist 7>>>>>70>>>>>700W
Assist 8>>>>>85>>>>>850W
Assist 9>>>>100>>>>>1000W

Personally I am not a fan of having a control strategy that reduces current with increased cadence. I can see the thinking behind it for providing improved economy though. It also gives you a bit of a boost getting up to speed and backs the power off once you are up to speed. Without having a torque sensor, its probably the best way you can simulate the torque effect through the pedaling range.

For me though,if I am pedaling at a higher cadence, its to increase my road speed. Subsequently it becomes counter productive to then reduce the assist when in reality, this is the time I actually need the assist to give me the best chance of sustaining this increased speed.

Try bumping up the Slow Start Model if your looking for a faster PAS start up ramp.

Been up and down the range of settings here already. I might do a bit more experiment here but so far I have found keeping Slow-Start mode in its mid range keeps the starting transition nice and smooth with the increase in starting current giving it a nice subtle boost on startup.

Have you used a watt meter to see what your continuous amperage draw is at the above settings? For example, at setting 7, 700 watts, what was a continuous draw?

I'm asking because my battery is only rated for 15 amp continuous so I may need to limit to 720 watts in the programming

 

[Krautrock]

Help, for some reason I am no longer able to read or write to my BBS02. I have been programming with no problems for quite some time and then the last time I went to write to it nothing happened.
I am getting a connection still with the software but now when I try and read the drive I get no data, it will not write either???
Bike is still fully functional no display error and appears to have nothing wrong with it. I tried from another PC and same problem, checked the cable nothing wrong with that, anyone have any ideas?

Hi Pigold,
i had the same problem whle programming my BBS02 yesterday. Could not find the cause nor or solution.
There were no further answers on your request neither any statement of your own in this thread. So have you found
the reason for the problem?? thanks for any reply

 

[Tom L]

Are you sure you are getting a connection?
Have you checked that the com port is correct?
Go to device manager and check which com port number is used when you plug in the serial adaptor. You should see it appear in the list when you plug it in.

FYI Windows has the nasty habit of increasing the com port number and not releasing earlier used ones. You can reset them manually by reassigning the port number. Right click on any com port and select /properties/port settings tab/advanced/com port number/ and ignore the "in use" warning (if you are sure it is not in use). I had to release about 8 of these phantom unreleased ports doing this the other day. It's still a problem on Windows 8.1. Here's a better walk through that was written for XP: http://www.modemsite.com/56k/xptip.asp

 

[mclark999]

I have continued to experiment with what settings suit me best and have settled on the following for now.

Basic Page:
Setting the current limits at 5% increments for the first 4 assist levels gives me good control of low level assist. Then making the % difference wider at the higher levels of assist I can set stonger levels of PAS for high speed commuting without the need to use the throttle.


View attachment 2

Pedal Assist page:
Start current has been lifted to help make the PAS a little more responsive on startup.
The big one is Keep Current(%) Setting this to 100% makes the PAS follow the % current on the basic page. This means 100% current setting on the Basic setting page will give you 100% throttle on PAS.

View attachment 1

Throttle Handle page:
I have set the Designated assist to 7 because I use a button throttle that gives me full throttle when pushed. By setting it to 7, I get about 800W when the throttle is activated. If I had a normal throttle, I would probably set this to 9.

I have set the start current to 5% to soften up the start with the button throttle. If I was using a normal throttle, I would keep this at about 20%



These settings feel very nice for my setup. I might go back to the standard throttle now I have control over the software. I would then set % Speed in the basic page to 1% in Assist 0 to make this a throttle only assist profile.

Thanks Kepler - I just programmed my 48v 20A drive to the exact specs that you used and did not install the throttle. It works great!!! I've got the motor on a Trek FX and took it out for a 17 mile ride today. At level 5, I can pedal lightly and cruise at 20 mph. At level 9, I hit 24 mph without pedaling.

Anyway, just wanted to say thanks for leading the way on this. I'm going to love having this as my daily commuter. I have a 10 mile ride to work and don't want to get sweaty - no showers at work. I can do this at level 5. Then on the way home, I can set it at level 3 and get a nice workout on my 14 mile return trip.

 

[pjgold]

Help, for some reason I am no longer able to read or write to my BBS02. I have been programming with no problems for quite some time and then the last time I went to write to it nothing happened.
I am getting a connection still with the software but now when I try and read the drive I get no data, it will not write either???
Bike is still fully functional no display error and appears to have nothing wrong with it. I tried from another PC and same problem, checked the cable nothing wrong with that, anyone have any ideas?

Hi Pigold,
i had the same problem whle programming my BBS02 yesterday. Could not find the cause nor or solution.
There were no further answers on your request neither any statement of your own in this thread. So have you found
the reason for the problem?? thanks for any reply

My USB-TTL died I replaced it with a new one and all fixed, I suspect that I may have unplugged it with the power still on and fried it.

 

[bbike]

Check this out. Ready to use programming cable for the Bafang BBS: http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html

Pricey though.

Looks "Home Made" by an amateur too!

Today I received this programming cable from china. I just added it when shopping some other items from the same seller, and you're right; it was a genuine home made cable ....but that said, just connected to my Win7 laptop, startet the program an was connected to the new 750w motor without any cable or software issues. Missed all the fun making my own cable

Anyway, looks like the new Bafang 750w motors have a new model name SZZ9 and hardware/firmware numbers have been reset ( 750w 48V 25A - date 01 July 2014).

 

[izeman]

so you can confirm that you can't program the new versions?

 

[bbike]

I'm able to program the new version. Saved updates on Basic, Pedal Assist and Throttle page.

 

[speedmd]

Looks like my new cable connector is near exact size as my old cars alpine cd changer cable minus the key. Will do some more inspection and verify if they stuck to this standards pin spacing layout.

 

[geofft]

I'm able to program the new version. Saved updates on Basic, Pedal Assist and Throttle page.

This is excellent news - are you using the existing software or did the cable come with new software?

 

[Aushiker]

Greenbikekit are now selling what they called an bafang central driven kit eb-bus cable for $29.99 US. I am assuming this could be modified as a programming cable?

Regards
Andrew

 

[Tom L]

Nope. it's the wrong end of the cable. You need the opposite gender connector, i.e. the connector attached to the display.

 

[tahustvedt]

Nope. it's the wrong end of the cable. You need the opposite gender connector, i.e. the connector attached to the display.

Not true. You can just make a programming cable using the large connector instead.

 

[Tom L]

Oh yeah, you can. Sorry.

 

[tomjasz]

Greenbikekit are now selling what they called an bafang central driven kit eb-bus cable for $29.99 US. I am assuming this could be modified as a programming cable?



Regards
Andrew

Andrew, I was able to find 9 others for a group buy. Perhaps there are enough of your countryman to do the same?

Best,

Tom