BBS02 blown controller?

[Bikerider_]

So I think I blew my controller going up a slope on the highest gear.

It now sounds like this from the motor. I think I might have blown perhaps the Halls or the phase wires right?

This type of sound often comes from that, is not that correct?

I am just worried I might have blown something else, like the nylon gears(?). But then the bike should not be able to move forward at all right?

Now it only sounds really bad and then it stop after a while . Then I can do a short spurt again after walking 20 meters or so.


https://www.veed.io/view/983c0a06-f0d9-444d-9edf-0c500b02a6ec?panel=share
https://www.veed.io/view/de29294b-1d0b-47fb-94c3-935a5026f284?panel=share
https://www.veed.io/view/4b711258-cb3c-4595-aaa6-4718054c66c5?panel=share

 

[Mike L]

Sounds like the plastic gear inside is ready to let go. You won't know till you open it up.

 

[Bikerider_]

Sounds like the plastic gear inside is ready to let go. You won't know till you open it up.

Ah the nylon gears you mean, right?

 

[Mike L]

Yes the nylon gear that runs against the motor shaft. I would also look very closely at the free wheel ratchet.

 

[m@Robertson]

If you had a blown controller your motor would not be making any sound, because it would not be working at all. I agree with the other poster above that this sounds like something with the gears. Hard to say which one. Could be the metal pinion gear. You just have to take the thing apart and look inside. You'll be forever guessing until you open it up and look.

 

[Bikerider_]

If you had a blown controller your motor would not be making any sound, because it would not be working at all. I agree with the other poster above that this sounds like something with the gears. Hard to say which one. Could be the metal pinion gear. You just have to take the thing apart and look inside. You'll be forever guessing until you open it up and look.

Ah ok.
I blew it going up a hill with my heavy bike. Was also using the bbs02 firmware so it was quite overburdened.

This was on a fatbike of mine. I was not very pleased with the performance though. Any idea why my fatbike was so slow?
I overamped it like crazy and then I blew this gear. But I was actually not that pleased with the performance before it happened.

I have bbs02 on another bike and that one has way more torque and is much stronger than this one. On this one I have a 52volt battery. But still did not go very fast and climb any good I think. This is probably the reason why I broke something. Because I wanted to try if it could give me some good bursts of power going up that hill. Tired of the bad performace

 

[Bikerider_]

Yes the nylon gear that runs against the motor shaft. I would also look very closely at the free wheel ratchet.

That is the clutch right?
I actually changed that before on this one. Maybe I did something wrong when I installed it since that one went again ?
Anyway I will open it during the coming week.

 

[m@Robertson]

Ah ok.
I blew it going up a hill with my heavy bike. Was also using the bbs02 firmware so it was quite overburdened.

This was on a fatbike of mine. I was not very pleased with the performance though. Any idea why my fatbike was so slow?
I overamped it like crazy and then I blew this gear. But I was actually not that pleased with the performance before it happened.

I have bbs02 on another bike and that one has way more torque and is much stronger than this one. On this one I have a 52volt battery. But still did not go very fast and climb any good I think. This is probably the reason why I broke something. Because I wanted to try if it could give me some good bursts of power going up that hill. Tired of the bad performace

The problem could be the BBS02, which is not a heavy-duty motor, but could also very (VERY) likely be you and how you tried to ride the bike up the hill. A BBS02 is particularly susceptible to blown controllers from overloading that comes from going up a hill, but the internals are also at risk.

Riding it wrong will kill mid drives of all stripes. Usually something like a BBSHD will survive but will instead take out something further down the line, like snap a chain or taco a chainring.

Here, check this out.

https://talesontwowheels.com/2020/10/02/how-do-i-ride-a-mid-drive-ebike-without-breaking-it/

 

[Bikerider_]

The problem could be the BBS02, which is not a heavy-duty motor, but could also very (VERY) likely be you and how you tried to ride the bike up the hill. A BBS02 is particularly susceptible to blown controllers from overloading that comes from going up a hill, but the internals are also at risk.

Riding it wrong will kill mid drives of all stripes. Usually something like a BBSHD will survive but will instead take out something further down the line, like snap a chain or taco a chainring.

Here, check this out.

https://talesontwowheels.com/2020/10/02/how-do-i-ride-a-mid-drive-ebike-without-breaking-it/

Thanks.

Guess I will have to open it up and see. Weird thing is this bbs02 that I have in particular, should have been much stronger(or so I thought). But my two other bikes with the same motor are much stronger. They both accelerate much faster and have higher top speed.
Before I destroyed the internals on this one, going up that hill, I was trying it out for two days. And I think it was rather weak in comparison to my other bikes.

Maybe it could be that a fatbike is a lot heavier than a normal bike and therefore won't move and accelerate as fast. What do you think?
I have the bbs02b on this one. And I used an extension-kit to fit it into the crank of my fatbike. So maybe that could also be factor contributing to the slower top speed and acceleration. What do you think? I guess that should not be factor. But maybe it could. What do you think?

I am going to open it up and check out the internals and then fix it but maybe I should not try it out on this fatbike again. Maybe I need to get the bbs02b made specifically for fatbikes or the bbshd? I thought this one was going to be a lot stronger after installing the kit, and using the upgraded firmware to up the amps to close to 30, but was rather disappointed. I even installed a linkglide chain and a rear sprocket linkglide with a really big ring closest to the wheel, and an extra big frontring to increase torque and speed. But did not perform as I expected. So maybe this motor is better used on another regular bike when I have fixed it?

 

[Mike L]

Big front ring is not how a Fat Bike is usually geared, they usually have a smaller front ring than standard because of the extra weight, and where they are ridden off road. The bigger the front ring, the more you're loading the motor up, you have use the gears with a Bafang the same as if you had no motor.

 

[Bikerider_]

Big front ring is not how a Fat Bike is usually geared, they usually have a smaller front ring than standard because of the extra weight, and where they are ridden off road. The bigger the front ring, the more you're loading the motor up, you have use the gears with a Bafang the same as if you had no motor.

Hmm interesting and thanks for the explanation. I did not know that. That is probably why it went so slow then perhaps?

I thought I would get the best of both worlds if I went with a really big frontring and a cassette of nine speeds that had a really big ring closest to the wheel but a really small one at the outer end. So that is what I went for. I did so after watching this video:

I thought he meant that both the torque and the top speed would increase. Increased torque at the big ring. And then increased speed at the smallest ring. But maybe that is not the case? Also, maybe the acceleration becomes worse when gearing it up like this?

What you say makes total sense. How will the performance change if I go down from the frontring I have now? I have 52 teeth at the front and the rear sprocket is a nine speed of 11-46.

So I have a really large one up front and a large one at the back closest to the wheel. Then I have a small one at the outer end. I thought this was going to make the bike faster but also increase torque going uphill.

What do you propose I change down to at the front? Would 44 be better? Or is it better to go even smaller than that? How would this change the performance of my bike theoretically?

thanks

 

[Mike L]

What size wheels & tyres does your bike have? I work on Trikes mostly and the iCE Full Fat comes from the Factory with a 36 Tooth front chain ring. I have also set up a Greenspeed fat wheeled Magnum. and it runs 36 Teeth on the front as well, it blew the electronics because of too many teeth on the front.and too high a gear uphill. I would try yours with a 42 tooth on the front (smallest standard Bafang chain ring) you'll notice quite a difference. Fat wheeled bikes aren't actually that quick, it's just the way they are.

 

[Bikerider_]

What size wheels & tyres does your bike have? I work on Trikes mostly and the iCE Full Fat comes from the Factory with a 36 Tooth front chain ring. I have also set up a Greenspeed fat wheeled Magnum. and it runs 36 Teeth on the front as well, it blew the electronics because of too many teeth on the front.and too high a gear uphill. I would try yours with a 42 tooth on the front (smallest standard Bafang chain ring) you'll notice quite a difference. Fat wheeled bikes aren't actually that quick, it's just the way they are.

Aha that makes sense. Would this also improve the acceleration? I think the acceleration was really sleepy.

The wheels are 26 inch wheel 4,6 tyres. So I guess basically a 29 inch bike if compared to a normal diameter 29 bike. But with fat tyres.

So maybe, since the fatbike is not that fast overall, I would get a lot more out of it by gearing down to a smaller chainring then? Since the top speed, although higher with a larger front chainring, will not be able to increase to a large extent anyway, because of the bike's structure? Despite the increase in gear ratio compared to the other alternative of 36-42 teeth?

 

[Mike L]

I just watched the vid again and I wouldn't call the bike slow. However with the chain ring you have it is somewhat over geared for the weight it's trying to push, especially with rider aboard going uphill. This is just my opinion of course. I would definitely downsize the front ring, try a 42T Bafang sprocket first (smallest one they do) and watch what gear you are in going uphill. If you decide to go smaller than you will need a 110mm PCD adapter and a normal bike chain ring with the appropriate number of teeth.

 

[Bikerider_]

I just watched the vid again and I wouldn't call the bike slow. However with the chain ring you have it is somewhat over geared for the weight it's trying to push, especially with rider aboard going uphill. This is just my opinion of course. I would definitely downsize the front ring, try a 42T Bafang sprocket first (smallest one they do) and watch what gear you are in going uphill. If you decide to go smaller than you will need a 110mm PCD adapter and a normal bike chain ring with the appropriate number of teeth.

What do you think about this one in this link: https://www.aliexpress.com/item/100...APmOoKCW&utparam-url=scene:search|query_from:

It seems to have 36T and I believe it is made for "bbs" as they write. Not bbs02, they write "bbs". But should work right? It only has 36 teeth. Could be a good fit for me? Although I am not sure if it has a chainguard.

By the way is there way to calculate the right gearing for a specific bike online or something? Or is this just trial and error to find out?

 

[Mike L]

Some good stuff on Aliexpress, I've bought some good stuff off there.
That sprocket should fit OK as it has the Bafang bolt pattern, but the chain will sit outboard of a standard Bafang one. (Std sprocket dishes inwards.) The wide/narrow cut on the teeth work to keep the chain on. If you're using the bike to commute to work (or similar) then you may find the 36T has reduced the gearing a bit much. A 42T may well be the compromise you're looking for, you won't know till you try it. As I said pretty weel all my work is on Trikes.

 

[m@Robertson]

Ouch. a 52T front ring... I missed that. Big front ring is a disaster waiting to happen. Doubly so with a poor little BBS02. Lugging the motor via big gears is one of the prime ways to kill them.

Going big on the gears increases top speed, but only to a point. Even a much more powerful BBSHD is going to get lugged. People think that a 750w motor is 3x as powerful as a 250w motor so it should be able to take anything... but it doesn't work that way at all.

This article is a companion to the other one I linked to you earlier. Given your experience you can see why I wrote these. Mid drives are wonderful things but they absolutely raise the bar in terms of the i's to dot and t's to cross by the builder to get a successful result.

https://talesontwowheels.com/2022/08/01/how-to-build-a-mid-drive-ebike-that-doesnt-break/
The easy answer on front chainring is to do the minimum size of a 42T. This is the very short version of the recommendation and I am ignoring things like chainline considerations. 42T will get you the most offset and is the reason for the typical recommendation. Going to 40T requires a replacement motor cover and the smaller sizes lose you the offset you would otherwise gain from the 42T ring. Chainring offset on a BBS02 is also a lot less than it is on a BBSHD so you aren't gaining anywhere near as much, but you are still gaining needed straighter chainline.

 

[m@Robertson]

I did so after watching this video:

If you go big on the front, you REALLY need to know exactly what it is you are doing with gearing, your riding style and your terrain. For example, above, I recommended (STRONGLY) going to a 42T ring, and even mentioned a 40T ring and how thats a better choice in some respects (the motor needs to spin fast, period). But of the many BBSHD builds I have, I've got one with a 52T front ring. BUT I only did that after a lot of analysis on that particular bike, how I ride it and where I ride it.

• Always table-flat land
• On that table flat land, I only use three gears. The one I normally use, one upshift and one downshift.
• I have a specific cadence I want to ride in, and using the 52T, I go 4 cogs in to get that optimal cadence, which gives me dead-straight chain line, and the 4 cogs in means I am using a pretty big cog on the back that doesn't bog the motor.
• Oh and the bike is a 2wd set up so the front motor kicks in first so again the motor doesn't bog since the mid drive never has to grunt the bike up from a dead stop, and acceleration is a team effort so I don't strain the $hit out of the drivetrain coming up to speed off the line.

Those are a lot of planets that have to line up to allow a 52T ring to be a safe, smart choice. I am moving that bike to my home now (vs. then) which has a lot of hills, and the first thing that has to go is that big chainring in favor of a 42T.

Gear choices on a bike build usually evolve. There's what you think you need, then what it turns out you really need after some riding. I've been doing it long enough to know in advance of a build... mostly. But that was not always the case.

https://talesontwowheels.com/2020/05/03/mongoose-bbshd-update-musical-chainrings/

 

[Bikerider_]

Some good stuff on Aliexpress, I've bought some good stuff off there.
That sprocket should fit OK as it has the Bafang bolt pattern, but the chain will sit outboard of a standard Bafang one. (Std sprocket dishes inwards.) The wide/narrow cut on the teeth work to keep the chain on. If you're using the bike to commute to work (or similar) then you may find the 36T has reduced the gearing a bit much. A 42T may well be the compromise you're looking for, you won't know till you try it. As I said pretty weel all my work is on Trikes.

Maybe 44 would be ok?

I have one of those at home.

 

[m@Robertson]

Maybe 44 would be ok?

I have one of those at home.

Well, you can pretty much guarantee that ANYTHING is going to be better than a 52T on a BBS02 in terms of strain on your drivetrain. And since you own it already, that is a double bonus. You may be taking a bit of a dump insofar as chainring offset is concerned, though. Unless its one of these:

https://www.aliexpress.us/item/3256804726477420.html
The 36T you linked earlier would work fine but it is going to be too small to give you any offset, which will probably screw up your chainline.