DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

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skymons65   1 µW

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by skymons65 » Jan 31 2021 8:29pm

Well, here's a data point anyway. Just bought a BBS02 from Luna with a controller dated 11/20.


Has "The Issue".

If there's such a thing as a BBS02 controller fixed with firmware I can't find one.
Last edited by skymons65 on Feb 05 2021 9:35am, edited 1 time in total.

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by skymons65 » Jan 31 2021 8:54pm

I also still haven't heard anything reliable about why Bafang started making the PAS over-ride the throttle. I'd really like to know.

My speculation is that it has something to do with the different classes of ebike being distinguished by whether they have a throttle or not (in California anyway). (Class 1-no throttle. Class 2-throttle only). Maybe in some twisted logic, Bafang thought that making the throttle and PAS less "intertwined" addressed this somehow.

:confused:
Last edited by skymons65 on Feb 05 2021 9:36am, edited 2 times in total.

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by Shedster » Feb 03 2021 4:59pm

fechter wrote:
Jan 08 2021 10:55am
That's it. Just unplug it.
There is usually a little blob of silicone holding the plug but you can just pull hard and it will tear or you can slice it with a blade first.

If you're sure you won't ever want it again, you can also just snip the grey wire and leave the plug in.
Hi, I got my BBS02 up and running today. I disconnected the PAS as advised, I thought that would disable all the PAS system, but every time I turn it on I have to scroll the PAS to #5 on my display to get any decent power at all. It does work on throttle alone, I don't need to pedal, but it soon runs out of revs, like it's rev-limited, and I keep having to shift up gears really quickly. Have I missed something please? Cheers :-)
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fechter   100 GW

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » Feb 03 2021 11:31pm

There are settings in the programming you need to change. You need the programming cable and the software. There are several other topics talking about the programming. On mine, I have the throttle programmed to always give full power with no speed limit regardless of PAS setting. Sounds like yours is programmed to be a function of the PAS setting.

Quite a few people have reported good results with upgrading the firmware to solve the throttle problem. I can't say for sure it will work on a BBS02 and may be vintage dependent. Same cable is used to load firmware.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by skymons65 » Feb 10 2021 2:13pm

Sure thought I had followed fecter's instructions to the "t" here. But no joy. Still have the PAS over-ride on spare BBS02 controller after modification.

I used :

512-KSP13BU

KSP13BU
ON Semi Darlington Transistors
US HTS:8541210095 ECCN:EAR99 COO:CN

and

71-RN55D-F-100K/R

RN55D1003FRE6
Vishay Metal Film Resistors - Through Hole
US HTS:8533210090 ECCN:EAR99 COO:US


and its a controller dated 9/16.


Any advice?
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fechter   100 GW

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » Feb 11 2021 7:59pm

I think you have the two outside legs swapped around. The emitter should go to ground. Try reversing them.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by skymons65 » Feb 12 2021 2:46pm

Got it! Works perfectly now. I suppose I probably should have first made an attempt to understand how a transistor works (i. e. understand which leg is the emitter) before I did this modification. But I guess this proves anybody, regardless of their understanding of electronics, can do this.

Can't thank you enough fechter. You (and Rassy et. al.) have done an invaluable service here.

If I could only get Bafang and their distributors to be as helpful and forthcoming.

Thank you!

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by Rassy » Mar 01 2021 8:38pm

Well, after 3 years of regular use the controller dated 9/2016 that I "fixed" started cutting out on a ride today. The display stayed on so I knew power was getting to the controller, but the assist would stop and the throttle would not work. Most times after losing three or four MPH both the throttle and the PAS would kick in again for a while. Then I discovered that with just fairly high throttle usage it did not cut out until I had to slow down. So I went to PAS level 0 and rode for several miles just using the throttle and had no more issues. I will pull out the controller and see what I can find and report back. If nothing is obvious I will probably replace the entire fix with new parts.

Too bad for me, but I traded off a good BBS02B that I had on the shelf to a local friend for a new trike he had purchased. About a week ago the controller in his BBS02B stopped working completely and I swapped it out for the last good early date BBS02B controller that I still had on the shelf. That controller came out of the BBS02B that started giving me problems today and I had never replaced it because the "fixed" controller worked as good as the original, at least for 3 years until today!

Just for interest, In early February I was having some winter blues along with covid blues and decided it was time to treat myself to a 48V torque sensing PAS TSDZ2 with a throttle and a VLCD5 display. My plan was to install it on the very trike that I had problems with today, but even though the trike had a Bafang BBS02B on it the Tong Sheng TSDZ2 would not clear the frame member. Not to be cheated out of experiencing torque sensing VS Cadence sensing PAS I purchased a new trike that the TSDZ2 could be installed on only to then discover I had been sent a 36V unit instead of the 48V unit I had purchased. Now due to backlog issues I am still waiting for my 48V unit. I'll start a new thread for the build when I fill like it.

EDIT: I finally got the correct TSDZ2, but I didn't like it at all. Unlike the BBS02, which you can set up the way you want it, the open source programming available for the TSDZ2 is very complicated looking and did not excite me at all. The problem for me is that I am old and don't have the energy or stamina to apply enough pressure on the pedals to unleash the power within. The TSDZ2 will be going to a friend for his Trek bike. He is a strong pedaler and excited about testing the torque PAS.
Last edited by Rassy on Apr 20 2021 7:46pm, edited 1 time in total.
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Two Delta Trikes equipped with a Bafang BBS02
viewtopic.php?f=28&t=88536&p=1291260#p1291260

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by Baron » Mar 24 2021 6:26pm

I was wondering if anyone could help with my issue. I ordered a BBSHD from Luna this month, and I think I might have the throttle issue described in this thread. I ordered mine with the "universal thumb throttle."

My issue is this: under any PAS setting, the throttle only operates at either 0% or 100% wide open. There is no in-between, or progressive ramp up with the throttle, it might as well be an on/off switch. There's 6 different PAS settings on my display, 0 through 5, and the issue is the same no matter the PAS setting. This was verified by putting my bike on a bike stand and testing the throttle with the rear wheel off the ground.

Also, the PAS system seems to work the same way when using the pedals rather than the throttle. There is only one motor speed that the BBSHD seems to work at, 100%, again there is no variable speed that changes depends on the pedaling speed. I don't know if this is how to BBSHD PAS is designed to work but it seems like a pretty crappy implementation, because at any PAS setting over 1 the motor completely outpaces any human effort, turning it into "ghost pedaling."

I don't really care about the PAS issue but what would be the best step forward from here to fix the throttle? Contact Luna or attempt to do the fix outlined by Fetcher in this thread? Has anyone contacted Luna about this issue, and what was their response? I would prefer they replace the controller or offer another fix rather than have to tear apart the BBSHD myself.

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fechter   100 GW

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » Mar 24 2021 10:12pm

The throttle issue sounds like mine. Several members have reported good results by flashing new firmware to the controller to fix the problem. I can't vouch for compatibility of any firmware versions. My hardware hack will work regardless of firmware version.

The PAS problem can be improved by changing the PAS settings in software. The stock settings are terrible and function like you describe. Even with optimized settings, it still sort of sucks because there is no torque sensing on the pedals.

You use the same programming interface to do both things. Maybe try to talk Luna into giving you one.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by Rassy » Apr 20 2021 7:27pm

My fix, described in the first post of this thread, died after 3 years of use. I have updated the first post with an edit describing a very simple alternate fix for this problem that does not require any electronic parts or digging into the controller potting. Of course it will still void your warranty. :cry:

EDIT: I just purchased a BBS02 that was manufactured just last month. To my disappointment it suffers from the PAS/Throttle issue Bafang introduced in 2017, and I will be doing some work on it soon. I wanted to mention here that this new BBS02 had the worst programming I have ever encountered, namely it jerked the drive chain when operating in any PAS level every time you stopped pedaling and then resumed pedaling. Also, the throttle never supplied any more power than the various PAS levels you were sitting in. After resetting many parameters all is good in this area. :D
-Rassy-

Two Delta Trikes equipped with a Bafang BBS02
viewtopic.php?f=28&t=88536&p=1291260#p1291260

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » Apr 20 2021 10:13pm

Can you post a picture of how the button is mounted?

Also, some reports indicate the "fixed" version of BBSHD firmware will also work on the BBS02 but I can't confirm.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by Rassy » Apr 22 2021 10:30pm

Excellent question fechter, I decided against making any modification to the throttle and instead I'm using a latching button switch next to the thumb on the opposite side of the handlebar from the throttle. Since this thread has become quite long and mostly about the electronic fix to the problem I have started a new thread for discussions concerning this very simple fix:

viewtopic.php?f=28&t=111469
-Rassy-

Two Delta Trikes equipped with a Bafang BBS02
viewtopic.php?f=28&t=88536&p=1291260#p1291260

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by TNC » May 03 2021 11:41am

fechter wrote:
Mar 24 2021 10:12pm
The throttle issue sounds like mine. Several members have reported good results by flashing new firmware to the controller to fix the problem. I can't vouch for compatibility of any firmware versions. My hardware hack will work regardless of firmware version.

The PAS problem can be improved by changing the PAS settings in software. The stock settings are terrible and function like you describe. Even with optimized settings, it still sort of sucks because there is no torque sensing on the pedals.

You use the same programming interface to do both things. Maybe try to talk Luna into giving you one.
fetchter, as you can tell from my post count, I'm new to this site/forum, but I have researched lots of sites quite a bit in preparation for the install of a BBSHD on my '08 Santa Cruz Nomad...looking for the pros, cons, and experiences of others. I ran across this specific post about the Throttle and PAS, saved the thread, and kept the issue in the back of my mind.

I bought a partial kit from Bafang USA the first of April which included the motor and 500C display. I got the rest of the items mainly from Luna including the program cable. This setup is pretty much dedicated only to true, off road mountain biking trail use. The first outing with an unmolested program exhibited the usually mentioned abruptness and extreme power "kick-in" at unwanted times on a tight trail. I didn't putz with the throttle on this first ride, as I was just trying to get used to riding an MTB with a motor. I work part time at a bike shop as a mechanic and have tried our Trek and Specialized emtb's...quite another animal with torque sensing of course.

Anyway, back home and did a couple of tweaking sessions on the program and really smoothed out the power delivery for off roading. I also really tamed the throttle input down where it became more usable. That's when it struck me that my throttle works seamlessly while pedaling with pedal assist. It was smooth through out the range with or without pedaling. I was expecting the annoying glitching as described by most here with the throttle and PAS. So, I think you're right about some of these units not having that issue anymore, at least perhaps on the BBSHD. I doubt anything I did in the reprogram eliminated the problem I had seen described. I just did the often standard approach of softening up the throttle and getting it to respond on its own under assist level 9. So, from this do you think that annoying element was removed in some units or am I missing something? I'm not complaining because the way it functions now is excellent. I mainly use just pedal assist when trail riding, but the smooth introduction of throttle has been nice when sort of stalling in a rock section or starting from a stop in a rock section when you're trying to clip in and start rolling. As a life long dirt motorcycle guy, I'm used to having some power kick in with a throttle, so this has not seemed an alien experience to me...and frankly the throttle is one element I think is useful in key situations that is missing in most factory emtb's.

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » May 04 2021 8:12am

The newer units appear to be shipped with the "fixed" firmware so it sounds like you got lucky and have the good firmware version.

One trick I learned was if you want to cut the power instantly while using the PAS, just pedal backward. Otherwise the motor keeps going for a split second which can be bad in a technical situation. I find the throttle useful when starting out on a steep hill or when you want to keep the cranks up for ground clearance.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by TNC » May 04 2021 9:41am

fechter wrote:
May 04 2021 8:12am
The newer units appear to be shipped with the "fixed" firmware so it sounds like you got lucky and have the good firmware version.

One trick I learned was if you want to cut the power instantly while using the PAS, just pedal backward. Otherwise the motor keeps going for a split second which can be bad in a technical situation. I find the throttle useful when starting out on a steep hill or when you want to keep the cranks up for ground clearance.
On that first outing I described with the OEM delivered program, I was using my hydro brake cut-off switches by tapping the brake lever(s) to kill the motor coming into turns and such where the motor was wanting to keep running, as you know. After slowly getting my head around the listed tuning elements in the program and the experiences recorded by others, I think I've smoothed out that tendency at "overrun", if I understand that description properly. Still, it's very much like riding a dirt motorcycle where you come into the corners or dodging around obstacles, and you always get on the brakes to stop or slow down the momentum of a 250-300 pound dirt bike in those cases. The brake cut-off switches are working well for me in a similar way.

Speaking of dirt motorcycles, I'm noticing on a couple of the off road motorcycle forums I'm a member of that some of those folks have Bafangs and really like them on their previously pedal-only MTB's. I get the impression that dirt motorcycle riders may take to the power characteristics and aggressiveness of the mid-drives a little easier than those who've only been MTB riders. Just an anecdotal observation, no science involved...LOL! I'm loving the way these motors can be tweaked to better fit riding preferences, and I want to thank folks like you and the many others who have submitted a lot of detail on tuning options, pros, and cons.

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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by fechter » May 04 2021 9:53am

I'm a long time motorcycle rider and rode my BBSHD for over a year with the PAS disabled. Throttle only. It was very natural to me and even after fixing the PAS, I still go with throttle quite often for more precise control.

Interestingly, I was recently stopped by a park ranger who asked me if my bike had PAS. I told him it did. He said that throttles are not allowed on the park trails. I really don't understand where they come up with stupid rules like this. So to really be compliant, I'd have to disable the throttle when on park lands, but it would be OK on the street. What I do instead is I always pedal, whether I'm using the throttle or not and I don't ride like an ass.
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Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

Post by TNC » May 04 2021 10:27am

fechter wrote:
May 04 2021 9:53am
I'm a long time motorcycle rider and rode my BBSHD for over a year with the PAS disabled. Throttle only. It was very natural to me and even after fixing the PAS, I still go with throttle quite often for more precise control.

Interestingly, I was recently stopped by a park ranger who asked me if my bike had PAS. I told him it did. He said that throttles are not allowed on the park trails. I really don't understand where they come up with stupid rules like this. So to really be compliant, I'd have to disable the throttle when on park lands, but it would be OK on the street. What I do instead is I always pedal, whether I'm using the throttle or not and I don't ride like an ass.
That's interesting on the park ranger incident. I wonder how many park rangers really know the nuances of these emtb's and their operational elements? Maybe they have some training on this issue, but can you imagine trying to know all the particulars of each system on every bike out there? I go to the Big Bend area of Texas every late fall to ride my street legal 300cc bike. In the NP I notice more and more ebikes of various styles there. So far I haven't seen any enforcement issues from rangers or problems with the riders themselves. Now, they are staying on the paved roads and even some of the gnarlier jeep roads, so I think all is pretty much legal as to how they're operating.

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