New Bafang Crank-Drives

[teslanv]

I just lift my feet off the pedals when going down steep hills. It's a little tricky trying to remount at the bottom though.

JK...

Seriously, though the drive has multiple freewheels, so you can coast, back pedal if you are so inclined, and pedal without any resistance with the motor completely inactive. If your battery dies, you just pedal home.

 

[t3sla]

That is correct pj, so still not ideal.

Intercepting the throttle signal is certainly a better solution at least for the BBS as it drops power off immediately and recovers immediately when released. Makes gear change slick and crunch free. 8)

Nope, it can be perfect you just need to get Bafang to alter the delay parameter in their software and then spec if right with the gearsensor based on your IGH
But good luck doing that when you buy from aliexpress based dealers (hint to the ES amigos, those lovely sales girls want to beat you for your pesos like a pinata and they can drink you under the table while doing it)

Gen 2 fixes mechanical issues, Gen 3 resolves remaining software issues.
Alternatively you can pay more for a different MD and get more.

 

[Samd]

I see you are adapting to the local look in your avatar Tesla. We should organise a ride when you are back in M-town.

 

[gedong]

hello,

i was just going to order bafang BBS02, and then i heard they are going to improve the controller so might need to wait for couple months before they are ready..

just quick questions, if i use mid drive, when the battery out, will there be drag resistance from the motor ? and how bad it is ? or it feels like normal bicycle ?

thanks

 

[samsavvas]

Bafang introduced me to a Czech company during Shanghai cycle and we had a long talk about the excellent product they developed.
http://gearsensor.com/
It both well engineering and design
-IP water rating
-MCU for delay settings
-Plug n play

Only thing it needs is a better mold for mounting to OEM frames, but for now zip-ties work.

Anyway I was going to do some sales for this, but no need for me to add margin and time when you can just go directly to the source :wink:
info@gearsensor.com

These were discussed a few dozen pages back in the thread. I followed them up somewhere and recall being a bit dismayed at what seemed an inordinately high price. Have you investgated where you might buy the sensors from? Apart from cosmetics, how do you think they might differ from the basic brake cable sensors that several Chinese venfors sell?

Savvas.

 

[Aushiker]

Have you investgated where you might buy the sensors from? Apart from cosmetics, how do you think they might differ from the basic brake cable sensors that several Chinese venfors sell?

Could the HWBS do the same thing? I guess all it is doing is detecting a movement in the cable ... damn I think I should have added an extra one to my GreenBikeKit order.

Andrew

 

[Samd]

Gday Kepler, regarding 48V 500W wattages:
I got the derailleur adjusted right last night and tested the wattages according to the display of the c963 (not an inline meter). C963 comes with 3 PAS levels.
PAS1 pulled 250W on the flat as well as up hills. Throttle pulled 440W.
PAS2 was about 480W peak. Throttle boosted to about 550W.
PAS3 was about 840W peak up long hills. Throttle offered no more.

I pulled a long ~15% hill in PAS 3 and then immediately tested the motor case with a laser thermometer - it was at 34 degrees Celsius. Just warm. Obvious benefit of using an inrunner design I guess.

The bike also has an unpowered ezee hub on the front and an unpowered HS3540 Hyena edition on the rear (I didn't have any other decent unpowered wheels to build up my wife's longtail with yet). I think the 500W middrive alone may struggle a bit with three kids on the back and groceries up front on a big hill - not stop altogether but slow down to the point of kids wobbling and unbalancing. I think I might mount a second battery anyway and hook the torquey Ezee up for a bit of extra hillcclimbing on the way home. I suspect the extra juice of the 750W unit would remove this need. Which would be nice as a QR front wheel would make it easier to put in the family van.

I did try to swap the 48V (55V HOC) battery for a 15s lipo charged to 61.8V. The HVC bought up an error 7 and wouldn't let me go any further

 

[samsavvas]

Could the HWBS do the same thing? I guess all it is doing is detecting a movement in the cable ... damn I think I should have added an extra one to my GreenBikeKit order. Andrew

Dunno - we're all waiting for someone to experiment!

Savvas.

 

[samsavvas]

I note that the Bafang CST rear hub motor is being supplied by at least one seller with a proper torque sensor of some kind. See: http://www.aliexpress.com/store/pro...-motor-SYX-E-0136v250w/326611_1260167984.html

I'm not sure how 'new' this set-up might be but it leaves me wondering how soon we might see the BBS sold with a torque sensor too...

Edit: Actually, I wonder if this really is a new 'torque sensor'. I have now read an earlier ES posting which mentions a Bafang '32 pulse' cadence sensor (which I've never seen). Is that what we're actually looking at here or is the wired BB pictured something new? I suspected the latter only because the listing also has what seems like a new sealed BBS-like wiring harness referred to as 'EB-BUS'!

Savvas.

 

[Aushiker]

Could the HWBS do the same thing? I guess all it is doing is detecting a movement in the cable ... damn I think I should have added an extra one to my GreenBikeKit order. Andrew

Dunno - we're all waiting for someone to experiment!

Savvas.

Well if Australian customs would clear my battery (does not pay for EM3EV to put the value at $41.00 US ) I could give it a shot with the bike on the stand. I have to re-cable the rear derailleur anyway so an easy test.

Andrew

 

[magdav]

This thread has made for some great reading, thanks! It looks like we in Tasmania are in for a law change from 200W to 250W 25km/h pedelec so an electric bike is starting to look like a good option. But the few shops still only have rubbish and it makes it hard to actually see any of the options.

From what I've read the Bafang mid drive conversion is nearly ideal for me. My main concern is my 10 minute morning downhill commute, which starts on a steep dirt track and ends flat out in city traffic. Given that I can't legally the use motor over 25km/h, is it likely to add resistance when pedaling fast unassisted? Or does the freewheel actions take care of this? Or is there something else I don't understand?

If it all goes well maybe I'll build something more powerful to get me up the mountain at my back door. Cheers.

The 250w one will get you up the mountain albiet slowly, I have a crank drive with the similar wattage on a dutch style bike and it would do it.
Crank drives are the ideal for a legal ebike in Hobart as they don't cook climbing steep hills.

Thanks for the advice! The 250W unit arrived from AliExpress (GE Battery) the other day and installed very easily with a 36V/11.6Ah pansonic NCR bottle battery. It works a treat, helps a lot on the hills and still lets me ride unassited at traffic speed downhill. Going up particularly steep hills it still needs a lot of pedal force to keep going, but I expected this due to the single large crank gear and extra speed.

I have observed that the PAS on max power setting seems to be significantly less powerful than when using the throttle. For example, with a fair amount of pedaling I can go 15km/h on a fairly steep hill with PAS, but at maximum throttle I max out at about 20km/h with similar pedal force. It seems a little strange that the unit does not get close to full power when it is really needed, and I was wondering if this is normal, what the cause is and if there is a fix?

The main reason I ask is that I plan to remove the throttle to comply with local laws - it would be nice not to loose that ~20% of power!

 

[Kepler]

Gday Kepler, regarding 48V 500W wattages:
I got the derailleur adjusted right last night and tested the wattages according to the display of the c963 (not an inline meter). C963 comes with 3 PAS levels.
PAS1 pulled 250W on the flat as well as up hills. Throttle pulled 440W.
PAS2 was about 480W peak. Throttle boosted to about 550W.
PAS3 was about 840W peak up long hills. Throttle offered no more.

I pulled a long ~15% hill in PAS 3 and then immediately tested the motor case with a laser thermometer - it was at 34 degrees Celsius. Just warm. Obvious benefit of using an inrunner design I guess.

The bike also has an unpowered ezee hub on the front and an unpowered HS3540 Hyena edition on the rear (I didn't have any other decent unpowered wheels to build up my wife's longtail with yet). I think the 500W middrive alone may struggle a bit with three kids on the back and groceries up front on a big hill - not stop altogether but slow down to the point of kids wobbling and unbalancing. I think I might mount a second battery anyway and hook the torquey Ezee up for a bit of extra hillcclimbing on the way home. I suspect the extra juice of the 750W unit would remove this need. Which would be nice as a QR front wheel would make it easier to put in the family van.

I did try to swap the 48V (55V HOC) battery for a 15s lipo charged to 61.8V. The HVC bought up an error 7 and wouldn't let me go any further

Hey Sam, thanks for posting those numbers. Makes it a little clearer what the real differences are between the 500W and 750W. Basically 250W between the two no matter how you crunch the numbers. I actually have mine turned down to 850W peak now so I don't need to worry about overheating it. IMO 850W is the sweet spot for this drive.

 

[Kepler]

I have observed that the PAS on max power setting seems to be significantly less powerful than when using the throttle. For example, with a fair amount of pedaling I can go 15km/h on a fairly steep hill with PAS, but at maximum throttle I max out at about 20km/h with similar pedal force. It seems a little strange that the unit does not get close to full power when it is really needed, and I was wondering if this is normal, what the cause is and if there is a fix?

The main reason I ask is that I plan to remove the throttle to comply with local laws - it would be nice not to loose that ~20% of power!

I think if you put a Watt meter on the drive, the peak on PAS only would be 250 to 300W. Unfortunately the reality is that 250W has trouble pulling the skin off a grape.

 

[amigafan2003]

I have observed that the PAS on max power setting seems to be significantly less powerful than when using the throttle. For example, with a fair amount of pedaling I can go 15km/h on a fairly steep hill with PAS, but at maximum throttle I max out at about 20km/h with similar pedal force. It seems a little strange that the unit does not get close to full power when it is really needed, and I was wondering if this is normal, what the cause is and if there is a fix?

The main reason I ask is that I plan to remove the throttle to comply with local laws - it would be nice not to loose that ~20% of power!

I think if you put a Watt meter on the drive, the peak on PAS only would be 250 to 300W. Unfortunately the reality is that 250W has trouble pulling the skin off a grape.

After playing with some settings for programming my 48v500w BBS02 (setting work mode to 40 and current decay to 8 mainly) I have managed to close the gap between throttle amps and PAS amps - throttle peaks at 1100w and PAS peaks at 870watts.

 

[Kepler]

Nice. I have set work mode to 80 and current decay to 8. Setting work mode to 80 stops the power ramping down too much with high cadence and as you found, current decay set to 8 gives you a big boost to PAS output. I have limited this to 850W but was seeing over 1000W on PAS before limiting the current a tad. I like being able to pedal at 50kph continuous on flat ground 8) .

 

[pjgold]

Nice. I have set work mode to 80 and current decay to 8. Setting work mode to 80 stops the power ramping down too much with high cadence and as you found, current decay set to 8 gives you a big boost to PAS output. I have limited this to 850W but was seeing over 1000W on PAS before limiting the current a tad. I like being able to pedal at 50kph continuous on flat ground 8) .

The other setting to play with is the Keep Current setting, it appears this setting controls the amount of current held on as you reach the max caddence.
The default appears to be 20% and my logic is suggesting that this means drop the power back to 20% of the assist percentage currently set over the range set by the Current Dealy setting.
So in numbers this means that if you have your assist is set at 100% it will drop back to about 20% at max rpm at 60% back to 12%. There is probably more to it than this with the controller taking into account speed versus cadence (work mode?)etc, however I know if you set this setting up to 100% the current does not back of much at all. That said I have left mine at 20% because it feels about right to me.

 

[Eprilia]

Hi all. I pulled a bone head move today and partially pulled the wires from the power button to the display and now it does not work
Does anyone know how to dissemble the C961 so I can see if the wires can be reattached? I have the face plate off, but I don't see any way to pry the display out from the housing. Is it glued in and may possibly need to be heated to remove? Any tips from anyone would be greatly appreciated.

Thanks Chuck.

 

[gedong]

just quick question, will this crank drive fit 29er 86,5 / 91mm pressfit bottom bracket ?

 

[nioko]

just quick question, will this crank drive fit 29er 86,5 / 91mm pressfit bottom bracket ?

As mentioned about 50 Times on the last 100 Pages, it's made for 68mm BB's.

 

[amigafan2003]

Hi all. I pulled a bone head move today and partially pulled the wires from the power button to the display and now it does not work
Does anyone know how to dissemble the C961 so I can see if the wires can be reattached? I have the face plate off, but I don't see any way to pry the display out from the housing. Is it glued in and may possibly need to be heated to remove? Any tips from anyone would be greatly appreciated.

Thanks Chuck.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=58780

1st post - display casing is platic welded - use a knife for flat blade to split open the casing.

 

[Electorbikes]

With NUVICI drive and just working on belt drive

 

[gedong]

just quick question, will this crank drive fit 29er 86,5 / 91mm pressfit bottom bracket ?

As mentioned about 50 Times on the last 100 Pages, it's made for 68mm BB's.

my frame is giant ATX which is required 86,5mm BB Pressfit.. so it's confirmed that i can NOT use this midrive.
thanks

 

[pacamu]

With NUVICI drive and just working on belt drive

could you provide more info on the belt drive fitting and alignment. is it a gates center track.

 

[Tom L]

I have been thinking about potting compounds for when my replacement controller arrives. I needn't have bothered:

 

[Aushiker]

BBS01 just had bullet-type connectors.

They are a two-pin connector by the looks. I need to make up a longer cable and would prefer at this stage to stick with these connectors rather than changing both ends to Andersons or something else so if anyone can help with what these are called that would be handy.

Thanks
Andrew