BBSHD thottle response.

PScott

1 mW
Joined
May 19, 2017
Messages
12
I finished my BBSHD build today! Works great under assist mode but the throttle is very abrupt. With assist set to 0 it's hard to modulate the thottle smoothly. It's like on or off. Is there a way to change how gradual the thottle ramps?

PScott
 
I had the same problem with mine. It was kind of strange and I'm not sure if they are all like that or just mine. I found that anytime I turned the pedals, the throttle would sort of disable and it would revert to the PAS settings. If I was careful to not pedal and only use the throttle, it behaved as expected. Going between throttle and PAS it would jerk rather violently.

If you have a programming cable, you might want to check the settings. There are several threads around on programming the settings.

Since I ride mostly on steep off-road trails, I found the PAS behavior dangerous, as it would sometimes want to launch me over the side of a cliff. I tried all kinds of settings, but never got it where I liked it. Eventually I gave up on it and disabled it by snipping the grey wire on the PAS sensor. After doing that, I reprogrammed the throttle to "by display's command" so I can change the current and speed limits based on the PAS setting. Now it works by throttle only and pedaling has no effect (other than to help move the bike). With a little practice, it's easy to maintain a setting where you contribute as much as you want by the pedals. I've been real happy with it since then.
 
I think you have the same problem I have on my BBSHD. Throttle works fine if your not peddling but when you start to peddle it's either full power or no power. Programming would not fix the problem. Luna is sending me a new controller to install. They have been very helpful. I'll post how it works when I get it installed.
 
This is basically just how the PAS system on the Bafangs works.

The amperage the controller gives under PAS is defined by the settings programmed for each PAS level. There are settings for % of amps, how fast it ramps up the amps, and maximum crank speed in each assist setting, as well as some other settings.

The PAS system has no way to know how hard you're pressing on the pedal, it only knows that the pedal crank is turning, and depending on it's programming, delivers the appropriate amperage until it reaches the programmed crank speed. This is generally how hub motor controllers work with PAS as well, but the difference here is that the controller also has no idea what gear the bike is in, and therefore has no idea how much torque is being delivered to the driven wheel, nor what actual speed it's trying to attain.

I personally disabled the PAS on my BBS02, by clipping the wire that connects the pedal crank sensor to the controller. I also programmed the throttle mode to "Current" instead of "Speed" so that it doesn't behave like the PAS. Instead of a request for a given speed depending on how much throttle I apply, I request a certain amount of amperage. Small amount of throttle, small amount of amperage. Full throttle, full amps. It makes fine control at low speeds in low gears much more intuitive, and much less dangerous imho. It also makes shifting alot quicker, and easier on the drivetrain. Just keep in mind that full throttle = full amps, even if you're in top gear and not moving, and this could quite easily blow a controller up.
 
Some companies have spent quite a bit of time figuring out their settings for the BBSxx systems. The one I bought from Paul at EM3eV had no bad behavior like you described.

Mine works like this with PAul's settings:
If you are not pedaling, the throttle works smoothly all the way from 0 to 100 percent.
If you are pedaling, the throttle will have no effect until you reach the throttle position that causes it to feed more power than the PAS system is already contributing, then the throttle works smoothly from that point on to 100 percent. This seems to work fine to me.

I know that Karl did a lot of work getting his BBXxx settings just right, and talks about how great the system is with his settings (Karl's Special Sauce is what he calls the settings). It took quite a bit of time for people to come up with the settings that worked than the ones from the factory.

Here is a good place to start (Karl's stuff):
https://electricbike-blog.com/2015/06/26/a-hackers-guide-to-programming-the-bbs02/
 
Same here. My BBSHD was awesomely programmed from Biktrix (Canada). Amps proportionnal to throttle.
 
bhaaf said:
I think you have the same problem I have on my BBSHD. Throttle works fine if your not peddling but when you start to peddle it's either full power or no power. Programming would not fix the problem. Luna is sending me a new controller to install. They have been very helpful. I'll post how it works when I get it installed.


I received the new controller. Throttle is now smooth peddling or not peddling. Everything is now working perfectly. Thanks Luna!
 
Thanks for posting the results. I suspect my controller may also be actually bad but I merely worked around it by disabling the PAS. I might have to go for a new controller.
 
I've got a new BBSHD kit from Luna as of a couple of months ago and am not happy with it at all.

I _expect_ (because it's what i have with an older 36V, BBS02 on another bike) that at assist-level-0, PAS / pedalling should be ignored completely, and only the throttle is controlling the motor's output. But that doesn't seem achievable via programming.
It must be a firmware issue.

Luna swapped me one motor already, citing firmware, but ... 'issues remain.
It's difficult to properly characterize, but suffice it to say that there are "bad/undesirable interactions between PAS & throttle".

'Anyone know how the firmware on these is even programmed? Would it entail a chip replacement, or can it be done over the cable? I'm not proposing to try and do any firmware mucking myself ... just wondering how it's actually done.

In the meanwhile, i don't know what to do. Luna's not been very helpful so far.


*----->
 
I don't think it's really Luna's fault. It's what they get from Bafang. On the controller board (under the potting) there is a programming port I assume is used to load the firmware. Nobody other than Bafang seems to have the firmware or the interface to load it.

It's hard to believe they would sell a bunch a units with this kind of bug in the firmware. I also have to think it should work properly if the gear change sensor was installed. I've never even seen the gear sensor so don't know how it works.

If you could find an "old" new controller with the old firmware, it would likely solve your problem.

There is a longer thread about this somewhere...
 
Here is one of the other threads on this topic:
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=91306&p=1331654&sid=55f346766596e30fd92696121f96a1a4#p1331654
More folks are realizing that this is a problem with (all?) of the new controllers. My experience is only with BBS02A and BBS02B systems, but after installing and using both the A and B units that worked properly I figured the one I purchased in August of 2017 was just set up wrong. After purchasing a programming cable and doing a lot of research it seems to be related to a firmware change (or unknown setting) and so far there is no known fix. At first it seems that the system is just set up wrong, which results in a "jerky" throttle, and you can make some programming changes to help smooth out the throttle response, but you can't "fix" the actual problem. You can either use the throttle without pedaling (except for full throttle) or you can pedal and not use the throttle (In any PAS level, 0 through 9).

I do want to mention that LUNA did an outstanding job for me concerning this problem. Ashley (co-owner of LUNA) ended up locating an older used BBS02B controller that worked properly and she swapped it out to me for the controller that came on the BBS02 that I purchased from LUNA in August. But no one seems to have a stock of these controllers and it also seems that all the new complete systems that are currently available have this problem.

I have sent a "contact" message to Bafang concerning this issue, but it doesn't appear that they are going to answer. Ashley also said she would check with her Bafang contacts, but I've not heard anything yet.
 
Rassy & fechter, thanks for your replies.
'Suspect you're right ... it's not Luna's fault, it's just what they've ended-up with from Bafang.
But it's most annoying all the same.
I do think Luna (and other OEMers?) need to press Bafang for a solid solution, ASAP.
I really can't deal with it, and that bike sits idle.

For the record, the firmware on my (annoying) BBSHD is indicated as version "1.0.0.4".

If the solution ultimately involves a firmware update (more than likely) then we need some way to do this "in the field" for ourselves, as shipping motors (or even just controllers) back-n-forth seems absurd.


*----->
 
I wish pressing Bafang worked. The BBS02B landed on Luna shelves without any notification of a change. It took a couple of years and another reseller in China to get a decent part supply chain. If not for this site and the fella,s posting, we,d be SOL. ES made Bafang and they remain aloof.
 
Well said Tom. I've already told a number of folks not to buy a new BBS02B at this time because they would probably get one that didn't work "correctly". Even though I have currently resolved my immediate problem I have been unable to find out if this is a permanent "change" Bafang made on purpose for some reason or if it was just a mistake. Also, there is no way, that I know of, to determine which version you would be getting when ordering a new one from one of the vendors.
 
tomjasz said:
I wish pressing Bafang worked. The BBS02B landed on Luna shelves without any notification of a change. It took a couple of years and another reseller in China to get a decent part supply chain. If not for this site and the fella,s posting, we,d be SOL. ES made Bafang and they remain aloof.
The more I follow Bafang developements of their hardware, the more I don't like it. Apart from the fact that their support is non-existent, as is their spare parts supply, they keep springing surprises. Only really interested in you if you buy a large quantity of motors from them.
I've thrown away their controller on my BBSx, replaced it with a 'plain vanilla' one, and let a Cycle Analyst V3 do all the 'thinking'.
 
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