Bafang BBS01 changing RPM

[pn_day]

Which is why I would always recommend an external controller, heat is easier to evacuate. I have finally found a supplier of a 15 Amp KT sine wave controller that is 36/48v and which has waterproof plugs to boot. All that needs to be done is to add an external speed sensor connector which is really easy because there is a useless light connector coming from the controller.

Hi AK.
Would you care to share which controller, and where from?

I'm about to put my GSM back on my velomobile, but want to run at 48V as I was also experiencing issues with the limited crank speed. (Short cranks on a recumbent mean that 90-115 rpm is not uncommon, even for an unfit bloke like me).

Thanks,
Phil

 

[anotherkiwi]

Hi AK.
Would you care to share which controller, and where from?

I'm about to put my GSM back on my velomobile, but want to run at 48V as I was also experiencing issues with the limited crank speed. (Short cranks on a recumbent mean that 90-115 rpm is not uncommon, even for an unfit bloke like me).

Thanks,
Phil

French version, hope this works for you - https://fr.aliexpress.com/store/738588?spm=a2g0w.12010108.pcShopHead_6004323.0

They do the KT 36/48v with waterproof plugs or the ordinary ones and 36€ shipped isn't too bad.

I will need pictures of your motor in the vélomobile

 

[pn_day]

Thanks AK - useful info.

I had the motor in there last year, but didn't like the slight resistance of the crank + increased resistance (I'm guessing back EMF) when trying to increase cadence.

I then stripped it all out and rode without, which at least told me more about the natural cadence I tended to use on hills. But a ~45kg aluminium velomobile on a 10% hill is even more challenging than I feared, so I'm now looking at putting the GSM back in, this time with 48V (and maybe running on very low assist levels all the time to avoid the 'cogging', rather than switching off completely).

For now I will use the S12S that I already have (shunt already modified to take down to 17A - will then reduce current further to bring down to the 15A recommended max for 48V).

Q-factor is a bit of a pain - I know the motor is not as wide as the TZ, but it is still wider than a normal BB. Straight cranks (Schlumpf) plus the Precialps spider have helped this.

Cheers,
Phil

 

[anotherkiwi]

Thanks AK - useful info.

I had the motor in there last year, but didn't like the slight resistance of the crank + increased resistance (I'm guessing back EMF) when trying to increase cadence.

I then stripped it all out and rode without, which at least told me more about the natural cadence I tended to use on hills. But a ~45kg aluminium velomobile on a 10% hill is even more challenging than I feared, so I'm now looking at putting the GSM back in, this time with 48V (and maybe running on very low assist levels all the time to avoid the 'cogging', rather than switching off completely).

For now I will use the S12S that I already have (shunt already modified to take down to 17A - will then reduce current further to bring down to the 15A recommended max for 48V).

Q-factor is a bit of a pain - I know the motor is not as wide as the TZ, but it is still wider than a normal BB. Straight cranks (Schlumpf) plus the Precialps spider have helped this.

Cheers,
Phil

Ah so you have a A4. Yesterday I took the trike for a run and came back happy that my condition is improving, lots more 5th gear km than last week. I think this is the ultimate vélomobile motor:

https://www.gngebike.com/ultralight-300w-kit

 

[pn_day]

Interesting find - I hadn't realised that GNG were working on smaller, lighter motors as well as the powerful but rather industrial units they used to make. I'll stick with the GSM as I have it for now, but will keep an eye out in the future... That GNG unit could have the potential for a thinner Q-factor as well - due to the different geometry.

Yes, I have an A4. Great fun, except when going uphill and running out of low enough gears Picture attached about half-way into my commute - the bike path at that stage goes past a local harbour.

 

[Deere John]

So finally I have got the BBS02 36V-version stator with rotor and changed from my BBS01. It was lucky I got the rotor as well. They are both bigger. But distance from flange to end of axle still the same, such as all holes and such. Have tried quick and it works! Will put all stuff together tomorrow for a real try.

 

[Deere John]

Ok, now I have two rides with the new BBS01.5

Short summary: Hard to tell what I felt.

I think I start in the other end. I certainly know what I NOT felt.

No more motor cutting off on me when pedalling normal. No matter what cadence it assisted anyway. I had to pedal like a maniac to get it to cut off because then finally outrun motor rpm. So this huge issue is no more.

I just swapped rotor/stator. Same (250W) controller, same programming.

So, what did I feel? It felt great! It feels like the 36V BBS01 should have felt from beginning I think. This cadence issue was really frustrating. It was worth every penny to get it fixed. Biking experience is so much better now when I just can pedal at whatever cadence I want and still get the assist I want.



Old worn parts of the BBS01 with BBS02 stator/rotor fitted.



Protrudes sligthly more to the left but no problem.

 

[pn_day]

Thanks for the update - sounds like it has been a success!

I've just finished putting my GSM build back in the velomobile - now running at 48V, and experienced a similar joy - in a quick test ride I was able to turn the cranks at ~115 rpm without any feeling that the motor was limiting the crank speed. Much better for my purposes.

Thanks for sharing the detail about the internal differences in the BBS - I'm sure this will come in handy for others in the future.

Enjoy the improved ride!
Phil

 

[Deere John]

Great to hear! I have ~113 rpm or so according to above table and I have not outrunned it yet.

 

[vfr400]

It's great that at least some guys are prepared to be pioneers. Thanks for sharing.

 

[mystryda]

Great to hear! I have ~113 rpm or so according to above table and I have not outrunned it yet.

I know you said that you're using the original 250W controller and programming.

Is the motor with the alternate (500W?) stator and rotor still only pulling 250W? Do you have an independent power meter that measures current or power?

I'm going to moving from the US to Germany and the setup that I currently run won't be legal over there. I'm thinking of a BBS01B with this rotor/stator substitution or bumping up the voltage. Like you, I'm accustomed to keeping a higher cadence, and 80RPM just won't cut it.

 

[Deere John]

I know you said that you're using the original 250W controller and programming.

Is the motor with the alternate (500W?) stator and rotor still only pulling 250W? Do you have an independent power meter that measures current or power?

I'm going to moving from the US to Germany and the setup that I currently run won't be legal over there. I'm thinking of a BBS01B with this rotor/stator substitution or bumping up the voltage. Like you, I'm accustomed to keeping a higher cadence, and 80RPM just won't cut it.

Sorry for late answer. Didn't see any notification.

You set the current limit in software. And the voltage is the same. So I think it is the same. Have the C963 display with power reading on it, seems like it stays the same as before. But I don't know exactly! but if you really want you can just measure the voltage/current when riding and set the current so that it stays nominally at 250W. That should do it? Don't know how they measure it, I mean, the Bosch CX I had before was way more powerful in short momentaneus boosts. But still 250W nominal.

 

[Nealh]

Sorry for late answer. Didn't see any notification.

You set the current limit in software. And the voltage is the same. So I think it is the same. Have the C963 display with power reading on it, seems like it stays the same as before. But I don't know exactly! but if you really want you can just measure the voltage/current when riding and set the current so that it stays nominally at 250W. That should do it? Don't know how they measure it, I mean, the Bosch CX I had before was way more powerful in short momentaneus boosts. But still 250W nominal.

Deere John, in affect I think you have fettled your own BBS01 etm model.

 

[Deere John]

Deere John, in affect I think you have fettled your own BBS01 etm model.

What do you mean?

 

[MontyPAS]

What do you mean?

Bafang BBS01B-ETM (MM G430.250) 36V 250W motor kit

Bafang BBS01B-ETM 36V 250W mid-drive complete conversion kit including LG MH1 cell battery

www.brightonebikes.co.uk

 

[Deere John]

...interesting! Didn't know of that Extra Torque Model

It seems the BBS01ETM is a BBS02 but specified for 250W It says it pulls 100 Nm torque!

It seems it has a 25A controller also. I still have the 15A controller. Mine is more legal than the ETM

 

[Nealh]

ETM is legal it has a manufacturer 250w rating.
One of the first sellers of ETM was someone in Norway.

 

[Marshall2389]

Ok, now I have two rides with the new BBS01.5

Short summary: Hard to tell what I felt.

I think I start in the other end. I certainly know what I NOT felt.

No more motor cutting off on me when pedalling normal. No matter what cadence it assisted anyway. I had to pedal like a maniac to get it to cut off because then finally outrun motor rpm. So this huge issue is no more.

I just swapped rotor/stator. Same (250W) controller, same programming.

So, what did I feel? It felt great! It feels like the 36V BBS01 should have felt from beginning I think. This cadence issue was really frustrating. It was worth every penny to get it fixed. Biking experience is so much better now when I just can pedal at whatever cadence I want and still get the assist I want.

Deere John, I have a BBS01b and am very interested in increasing the maximum cadence to which it can assist. This is a brilliant solution! So is it really as simple as ordering a BBS02 500 W version rotor and stator, take off the old ones, and install the new ones? No complicated programming to deal with the new motor hardware? It has run well for you, no problems? I really appreciate you sharing what you've learned.

Thank you for your time,

Elliot

 

[Deere John]

Deere John, I have a BBS01b and am very interested in increasing the maximum cadence to which it can assist. This is a brilliant solution! So is it really as simple as ordering a BBS02 500 W version rotor and stator, take off the old ones, and install the new ones? No complicated programming to deal with the new motor hardware? It has run well for you, no problems? I really appreciate you sharing what you've learned.

Thank you for your time,

Elliot

Hi Elliot! Glad to hear. It has worked very well. Can not imagine biking without this mod. Really great. And it is as simple as you wrote. Just change stator/rotor. No programming changes. And you are done!

 

[Marshall2389]

Hi Elliot! Glad to hear. It has worked very well. Can not imagine biking without this mod. Really great. And it is as simple as you wrote. Just change stator/rotor. No programming changes. And you are done!

That's amazing. I just ordered a BBS02 36V 500W rotor and stator. I can't wait to ride it with assist at my preferred cadence!