New Bafang Crank-Drives

[speedmd]

The discussion neglects the materials used in the helical gear box design. The hardened finely finished metal against a nice wide finely finished slippery plastic would have lower frictional losses at the expense of a bit of power handling. It also neglects the angle the gears are cut and quality of gear build and the load. More gets lost in poor fitting sloppy gear boxes than can be taken from a general written article. The fact that one is a noisy contraption and the other is near silent tells you more than a paper comparing similar quality builds. Fit and gear profile is everything here when talking gear box efficiency. I would be surprised that something like a cyclone setup is even as good with it's extremely noisy straight cut gears or if it will last near as long. Plus it wakes up every dog in route adding much hazard.

 

[samsavvas]

The freewheel the motor gear reduction system is a sprag bearing which is located in the white intermediate gear. This means the white intermediate gear and the gear attached to the motor's rotor do not spin when pedal without power. Again a nice smooth system with minimal drag and no reports of failure or lockup as yet.

OK - so it seems that before I mount my newly acquired BBS01 unit on the test bike and attach the chain etc, I should expect the cranks to spin relatively freely both backwards and forwards. Backwards because the first freewheel disengages the cranks and BB shaft from the chain ring and its carrier, and forwards because the second Sprag freewheel unlt only requires the cranks to turn the chainring assembly and one pinion/gear shaft when pedaling without power.

On the bench, this doesn't seem to be happening. When spinning the mounted cranks backwards, they freewheel for perhaps 1 turn or less. Spinning them forwards - well, they don't spin at all. It feels like the cranks are trying to turn a longish, high ratio gear-train if not the motor itself. I'm wondering if the Sprag clutch is not working properly because the unit is brand new and just needs a bit of use. I have no experience with such devices at all and don't know how they work. Maybe I should just install the drive and see what happens...

Or maybe there is some adjustment I can try while it's on the bench? Should I take it apart before installation and see if there's something I can do that might improve things.

What does the engineering collective think please?

BTW I bought this from Greenbikekit as an test unit pending a small-scale 'community buy' project my local bike group are planning. GBK were very reasonable to deal with but I don't much like the idea of sending it back to HK or wherever it came from. I will email them of course but would also appreciate any insights that those here with experience of the unit or who have had it apart might be able to offer.

Many thanks,

Savvas.

 

[greenspark]

Once we're on "porn"pictures, Could someone kindly post some of BB and crank axel.

Would Like to know if there's any way or modification that would make it fit on a Fat bike 100mm BB.

THX

In short, unless you can cut the BB to about 68mm wide, no. I presume you mean the BB is 100mm wide. We were able to fit the BBS01 to a 1951 Raleigh DL-1 that has a 75 mm BB by cutting the BB steel down to 68mm (3.5mm off per side). Because the shaft does not use the BB threads inside, the precision required to shorten is not as important. The BBS01 shaft nuts hold it using compression. However, cutting off over 30mm in the BB suggests you will be interfering with the engineering and could risk failure. Smarter to buy another standard bike with a 68mm wide BB and it then takes two seconds to install the shaft in the BB.

What kind of photos do you want?

 

[Kepler]

The freewheel the motor gear reduction system is a sprag bearing which is located in the white intermediate gear. This means the white intermediate gear and the gear attached to the motor's rotor do not spin when pedal without power. Again a nice smooth system with minimal drag and no reports of failure or lockup as yet.

OK - so it seems that before I mount my newly acquired BBS01 unit on the test bike and attach the chain etc, I should expect the cranks to spin relatively freely both backwards and forwards. Backwards because the first freewheel disengages the cranks and BB shaft from the chain ring and its carrier, and forwards because the second Sprag freewheel unlt only requires the cranks to turn the chainring assembly and one pinion/gear shaft when pedaling without power.

On the bench, this doesn't seem to be happening. When spinning the mounted cranks backwards, they freewheel for perhaps 1 turn or less. Spinning them forwards - well, they don't spin at all. It feels like the cranks are trying to turn a longish, high ratio gear-train if not the motor itself. I'm wondering if the Sprag clutch is not working properly because the unit is brand new and just needs a bit of use. I have no experience with such devices at all and don't know how they work. Maybe I should just install the drive and see what happens...

Or maybe there is some adjustment I can try while it's on the bench? Should I take it apart before installation and see if there's something I can do that might improve things.

What does the engineering collective think please?

BTW I bought this from Greenbikekit as an test unit pending a small-scale 'community buy' project my local bike group are planning. GBK were very reasonable to deal with but I don't much like the idea of sending it back to HK or wherever it came from. I will email them of course but would also appreciate any insights that those here with experience of the unit or who have had it apart might be able to offer.

Many thanks,

Savvas.

Seeing it is not spinning freely in both directions, the tightness must be in the BB shaft. check the locking nuts that hold the shaft in the drive bottom bracket shell. If these are too tight, they will lock up the thrust bearings. The thrust bearings may also be assembled incorrectly. Have a look on page 34 of this thread for some more pictures but it is quite an easy task to remove the axle and check things out. Just remove the gear cover first then on the no chain ring side, remove the internal nuts holding the shaft in place. These locking nuts are not tight as they set the tension on the thrust bearings.

See how you go with that.

 

[ErikDK]

Like samsavvas', my drive comes from Greenbikekit as well.

 

[zzmatias]

Hi Kepler,

Since you have ridden both Bafang’s mid and geared-hub drives. I’d be interested to know which one would be your favorite and any reasons.

I know they are different, and that the mid-drive would provide more torque for steep hills and perhaps is a bit quieter but slightly heavier and not sure if I could connect a Cycle Analyst and get the most of a 45V 12S pack.

Thanks,
Matias

 

[bose]

Is it possible that units without double freewheels exists? I got the answer from Amy at one Aliexpress store that they could not meet the demand when I asked for double freewheel (I have a slight thought that she did not really understand what I meant). Else than that she did not seem very keen on selling me a unit either, my money will go to a store with better service.

 

[Kepler]

Now there is curve ball. Surely not. I would be totally shocked if it was the case.

 

[Kepler]

Hi Kepler,

Since you have ridden both Bafang’s mid and geared-hub drives. I’d be interested to know which one would be your favorite and any reasons.

I know they are different, and that the mid-drive would provide more torque for steep hills and perhaps is a bit quieter but slightly heavier and not sure if I could connect a Cycle Analyst and get the most of a 45V 12S pack.

Thanks,
Matias

The mid drive is my favorite by a fair margin. main reasons are the handling and how quiet it is but I also like the fact that I can build the bike with a high quality wheel set back and front. Biggest negative for me is probably the difficulty in finding a good quality late model frame that the drive can be fitted too especially if looking for dual suspension.

You can still fit a CA if you want to. Just need to use a remote shunt. Someone did mention though that there is a new display for the drive that shows actual amps or Watts. Cant confirm this but if it becomes available, that would be the icing on the cake.

 

[greenspark]

Hi Kepler,

Since you have ridden both Bafang’s mid and geared-hub drives. I’d be interested to know which one would be your favorite and any reasons.

I know they are different, and that the mid-drive would provide more torque for steep hills and perhaps is a bit quieter but slightly heavier and not sure if I could connect a Cycle Analyst and get the most of a 45V 12S pack.

Thanks,
Matias

I'm not Kepler, but I have bought:

• (1) Bafang SWXK5 front motor
• (2) Bafang CST 700c rear hub motors
• (1) Bafang BBS01 250W Eurospec prototype (aluminium shaft)
• (1) Bafang BBS01 300W (350 reset to be legal in NZ) prototype (aluminium shaft)
• (23) Bafang BBS01 300W steel shaft motors with C691 display (we will keep seven for our bikes, the rest went to the buyers who joined out buyers group)
• (1) Bafang BBS01 350W steel shaft motor with a C695 display - this last one was a "try-it-out" from the factory and we like it the best

We are selling all our hub motors (also includes a Mac rear hub 500W, 50v, a CUTE 100F 350W (ha!)/36v and a MXUS 350W/36v front hub). We will be shifting completely to the mid-mount Bafang BBS01 motors.

Why?

The BBS01 is far less cluttered, amazingly quiet, very subtle, and it uses the gears. A hub motor is like driving a car with one gear, you either have to buy for torque or for top speed or buy an overpowered unit that turns your bike into a moped. I'm not sure how they did it, but the BBS01 is engineered differently than hub motors. It will tolerate slower RPM's, thus the 18a limit is OK. We find the range of a three-speed internal hub is sufficient, but the most interesting is installed with a NuVinci N360 hub that can be shifted while the motor is driving the chain.

It installs like an OEM kit. Indeed, we installed a number of them on Pashley classic city bikes and it is hard to tell that they did not come from the factory with the motor. The fact that the controller is inside the motor means one less device to attach, and in our experience the hub motors end up with a spaghetti mess of cables and wires. Each of those wires on a hub motor is one more thing to go bad in real-world conditions. In contrast, the BBS01 has three cables coming from the motor. One to the rear speed sensor, one to the battery and one multi-cable that goes to the handlebar where it splits into four... two ebrake, one display/speed setting and one (optional) thumb throttle (TT). After a bit of use however, we are not sure the TT is necessary. The pedal assist is good enough that find we don't use the TT except when looking to get a jump start into traffic.

It has a low and mid-point center-of-gravity, and with Cell-Man's new 29E Samsung batteries (2.0kg/11.2Ah), we can strap the battery to the lower seat tube for perfect weight and balance. We also found a $12 (NZD) new army bag that was a perfect fit for the battery, so it really is a very stealth-like look. The motor is small, and it is low and out of the way.

Having visited the Bafang factory, they are making some major automation changes. The old motors were hand assembled. The new stuff is being done on automated precision systems.

There still are some areas of fine tuning.

• They need to decouple the thumb throttle from the pedalec so it gets 100% power even if the display is set to zero PAS.
• They need a real torque sensor so it is instant on and instant off rather than the second delay. We hear this is coming.
• They should allow more field programming by qualified persons
• They should provide the option of no digital display, but only a On/Off switch with the 1-2-3 power setting. The digital display will be the first thing to fail.
• They need a better spacer for the display. It does not fit standard handlebars right, thus the installer has to use tape

BTW, not sure if you noticed, but CellMan has posted this news item "There are a few new products in the pipeline, including the popular Bafang BBS02 mid drive kits (in 36V, 350W and 48V, 750W flavours initially), due mid-February, hopefully not too much later." We had something to do with that one, and are very pleased that he will be offering them. Mid-February is coming up soon.

 

[greenspark]

Someone did mention though that there is a new display for the drive that shows actual amps or Watts. Cant confirm this but if it becomes available, that would be the icing on the cake.

Yes, the C695 display shows actually wattage, although it is uncertain how it is reading it. The 350W motor read about 300-340W up a steep 15 degree hill, then settles down to the low 100's. However, if the TT is pressed, it jumps to 600W range and there is a noticeable boost in power. We bought our 23 units directly from Bafang because we were prototype testers for them, so they tossed in a try this display. Highly recommended.

 

[Kepler]

Good to know. Thanks for that.

And good previous post too. 8)

 

[Kepler]

greenspark, have you seen any problems with freewheels in any of the directions with the drives you have brought in? What are your thoughts on the problems samsavvas is having?

 

[kampua]

Hi,

I am looking for a reputable China online shop to buy Bafang BBS02 from. I know about greenbikekit and BMS battery, are they good? Any other good ones?

 

[zzmatias]

Thanks greenspark. Your post was useful and quite detailed. I used to own a Tonaro mid-drive with a 48V config and I agree with the advantages of the mid-drive. My bike got stolen recently so I'm on the way of building a new one. I really like Bafang's mid-drive, the few things that still hold me to go and buy the BBS02 straight away are:

- Wait until a torque sensor version is released.
- I like the idea of a ultra-light setup (similar to Kepler's super commuter), which favours (lipo S packs with overcharged small motors). If I go with the BBS02 I would probably buy the Alfine-11 gear hub (although will add an extra Kg to the setup).
- Controller not compatible with Cycle Analist.

Do you know the real weight of the BBS02? One Alibaba seller says 4kg the motor and other seller claims 6kg for the whole kit.

 

[radoCol]

Hi

What's wrong in the picture (see the pic from the right, motor assembly)
http://www.aliexpress.com/item/48v-...-Motor-eletric-bicycles-trike/1259610070.html

Wires are coming up from the motor, looks like left side installation? Other pictures are ok but the pic from the right is not? What do you think?

My plan is to change my ugly and heavy Magic Pie 3 to the bbs2 48V/750W but the photo in the web page looks odd...

 

[samsavvas]

Hi,

I am looking for a reputable China online shop to buy Bafang BBS02 from. I know about greenbikekit and BMS battery, are they good? Any other good ones?

Greenbikekit were fine for my test unit - good communication and service despite the small problems I seem to be encountering with 'drag'.

However em3ev (Paul or 'Cellman') would be the go for a really high-quality, expert and dependable outcome. See references in the posts above.

Savvas.

 

[samsavvas]

greenspark, have you seen any problems with freewheels in any of the directions with the drives you have brought in? What are your thoughts on the problems samsavvas is having?

Before Greenspark responds I should just add that I have decided that in the forward-pedalling direction on my BBS01 the cranks are not trying to turn the motor - just the pinion and shaft. However my other descriptions of apparently excessive 'drag' in both directions with my particular unit still hold. I will be trying Kepler's suggestions for reducing load on the thrust bearings because it sounds very likely that it's excessive loading that is the problem!

Savvas.

 

[samsavvas]

Seeing it is not spinning freely in both directions, the tightness must be in the BB shaft. check the locking nuts that hold the shaft in the drive bottom bracket shell. If these are too tight, they will lock up the thrust bearings. The thrust bearings may also be assembled incorrectly. Have a look on page 34 of this thread for some more pictures but it is quite an easy task to remove the axle and check things out. Just remove the gear cover first then on the no chain ring side, remove the internal nuts holding the shaft in place. These locking nuts are not tight as they set the tension on the thrust bearings.

See how you go with that.

Extreeeeeemely helpful and reassuring suggestions. Many thanks. Will pursue this weekend and report back!

Savvas

 

[ErikDK]

Hi

What's wrong in the picture (see the pic from the right, motor assembly)
http://www.aliexpress.com/item/48v-...-Motor-eletric-bicycles-trike/1259610070.html

Wires are coming up from the motor, looks like left side installation? Other pictures are ok but the pic from the right is not? What do you think?

My plan is to change my ugly and heavy Magic Pie 3 to the bbs2 48V/750W but the photo in the web page looks odd...

Nothing wrong with that, it's the same kit as Greenbikekit

 

[Cinelab]

We bought our 23 units directly from Bafang

Do they do factory direct sales for quantities?

 

[Cinelab]

The BBS01 shaft nuts hold it using compression. However, cutting off over 30mm in the BB suggests you will be interfering with the engineering and could risk failure. Smarter to buy another standard bike with a 68mm wide BB and it then takes two seconds to install the shaft in the BB.

What kind of photos do you want?

Would like to see details on mounting the shaft on the BB.

The shaft's end, an how it couples with the the nuts. Could be interesting.

Someone mentioned on the picture of the other Mid-Drive that's coming, that it could possibly fit some kind of extension.

Wondered if that could be done on the BBS

 

[kampua]

Hi,

I am looking for a reputable China online shop to buy Bafang BBS02 from. I know about greenbikekit and BMS battery, are they good? Any other good ones?

Greenbikekit were fine for my test unit - good communication and service despite the small problems I seem to be encountering with 'drag'.

However em3ev (Paul or 'Cellman') would be the go for a really high-quality, expert and dependable outcome. See references in the posts above.

Savvas.

em3ev does not seems to be selling bafang mid drive motor. Anyone used BMSBattery.com?

 

[Somebodystopme!!]

Hi,

I am looking for a reputable China online shop to buy Bafang BBS02 from. I know about greenbikekit and BMS battery, are they good? Any other good ones?

I just bought one from www.asian-resources.com. They are an ebay seller and have them there.
I believe they are also affiliated with hallomotor.com as well.

I contacted them through Ebay and bought a 48v 750w BBS02 for $485 shipped.

I'll post again when I receive it and tell what condition it's in.

I ordered it on Feb 3rd but they're at the tale end of there Chinese New Year so it will not start to processed until feb 8th or so. Then maybe a couple of weeks to California.

 

[Melbourne]

Hi,

I am looking for a reputable China online shop to buy Bafang BBS02 from. I know about greenbikekit and BMS battery, are they good? Any other good ones?

Greenbikekit were fine for my test unit - good communication and service despite the small problems I seem to be encountering with 'drag'.

However em3ev (Paul or 'Cellman') would be the go for a really high-quality, expert and dependable outcome. See references in the posts above.

Savvas.

em3ev does not seems to be selling bafang mid drive motor. Anyone used BMSBattery.com?

I got it from aliexpress CNEBIKES..350W but they also have 750W?
Brought my kit/battery from aliexpress CNEBIKES
-36v 350w 8-fun mid motor is whole priced usd350 ( 48 T )
-36V 9AH tubelthium battery + charger is price usd150
-The freight for the all is usd125 via the ems
Delivery time to Australia = 4weeks

Other es members
ttp://www.aliexpress.com/item/48v-750w-8fun-bafang-bafun-motor-BBS-01-mid-Center-drive-position-Motor-eletric-bicycles-trike/1259610070.html

BUT someone said its 750w is backorder..out of stock... Email them and ask