New Bafang Crank-Drives

[Gab]

Speed MD

This is not close to the gng bb. It looks to me so far as much better than the isis stuff also. It is much better supported and hardened than your average bb. Cyclone stuff is not close to the quality of this kit from what I have seen

Regardless if the bafang BB is hardened or not( the cyclone square taper bottom bracket is hardened after all ) it will not be as strong as an ISIS bottom bracket because the outer diameter of the shaft is a lot larger and stronger on the ISIS then on the square taper. Many people with the stock GNG and cyclone square taper bottom brackets have bent the shaft with little hard offroad use, hence why the ISIS BB is so popular with heavy offroad users with the cyclone and GNG kits.

 

[deepfraught]

I don't think by logic though you can assume all square taper BB are the same poor quality as the cheapest one sourced for the GNG.
This one may be weaker than an ISIS, but it has yet to be proven where it sits in between. We should be waiting for
'here are pics of my busted bafang crank drive from... <usage scenario to failure>'

As for guides to usage and choice of power method, spinningmagnets site has a good bunch of articles with links to ES examples.

 

[amigafan2003]

Speed MD

This is not close to the gng bb. It looks to me so far as much better than the isis stuff also. It is much better supported and hardened than your average bb. Cyclone stuff is not close to the quality of this kit from what I have seen

Regardless if the bafang BB is hardened or not( the cyclone square taper bottom bracket is hardened after all ) it will not be as strong as an ISIS bottom bracket because the outer diameter of the shaft is a lot larger and stronger on the ISIS then on the square taper. Many people with the stock GNG and cyclone square taper bottom brackets have bent the shaft with little hard offroad use, hence why the ISIS BB is so popular with heavy offroad users with the cyclone and GNG kits.

ISIS BB's are a marketing gimmick - nothing more - an issue that pervades the "serious" cycling market. When riders "back in the day" were running standard 68mm square taper BB's in worldcup DH races you never saw more failed BB's than you do now.

The issue is whether you have a quality BB or a poor quality BB - not whether you have a square taper or ISIS BB.

 

[Gab]

ISIS BB's are a marketing gimmick

If they are a marketing gymick how come we haven't heard anyone bend the shaft on ISIS BB on the GNG and cyclone threads and most people upgrade to them? But we have heard many times people bend the Square Taper GNG and cyclone ones? The only reason we haven't heard from the Bafang is that it's a new product that hasn't been tested hard yet.

Yes sure quality of the BB will make a difference, but also more importantly the design plays a role. ISIS BB have a larger shaft diameter so they are inherently stronger in their design then square taper.

 

[deepfraught]

Yes sure quality of the BB will make a difference

Now you got it

 

[vel80]

Hello to all,
I import and sell e-bike parts and accesories in my country Bulgaria and it's pleasure for me to join this interesting debate!
I would like to share my first impression of Bafang bbs 36V 350W. I conducted some tests and found that it was able to climb a 30% gradient, without pedals. Moreover the system is able to start from standstill in the middle of the slope. This was made on 20' Dahon C7 with 14-28t cassette, using the first gear (28t). The total weight of me and the bike was 98.5 kg. My opinion is, that it's an impressive result for me compared to the the BPM geared motors, which I used to sell in me country. Actually I am interesting in performing the same test with Bosch system, which I found is the main competitor in this class. The problem is that, it's not possible to found a Bosch system with throttle controll.
I

 

[spinningmagnets]

Welcome vel80. several people have reported that when using smaller wheels, the 36V BBS02 is very adequate, but...when using a larger wheel, like the common 26-inch...the 48V version has more power for hill-climbing.

Are there many electric bikes in Bulgaria? Do the police bother you if you have a powerful E-bike? or, must you pretend that the bike is not more than the EU power limit of 250W?

 

[vel80]

Hi, Spinningmagnets,
The main problem in Bulgaria is, that there is no good road infrastructure for bikes. So, the cyclists have to ride on the trafic roads. The police doesn't pay attention on the bike's power lewels, so hi- powered e-bikes are not an exeption. BTW, I have a few BBS02 48V 750W on the shelf, but still not tested.
My next project is intended to be made in this spirit, but the bike's transmission is a question number one in my head now.

Welcome vel80. several people have reported that when using smaller wheels, the 36V BBS02 is very adequate, but...when using a larger wheel, like the common 26-inch...the 48V version has more power for hill-climbing.

Are there many electric bikes in Bulgaria? Do the police bother you if you have a powerful E-bike? or, must you pretend that the bike is not more than the EU power limit of 250W?

 

[speedmd]

Speed MD

This is not close to the gng bb. It looks to me so far as much better than the isis stuff also. It is much better supported and hardened than your average bb. Cyclone stuff is not close to the quality of this kit from what I have seen

Regardless if the bafang BB is hardened or not( the cyclone square taper bottom bracket is hardened after all ) it will not be as strong as an ISIS bottom bracket because the outer diameter of the shaft is a lot larger and stronger on the ISIS then on the square taper. Many people with the stock GNG and cyclone square taper bottom brackets have bent the shaft with little hard offroad use, hence why the ISIS BB is so popular with heavy offroad users with the cyclone and GNG kits.

Hi Gab

Any time you have large amounts of shaft sticking out you are at risk. I do like the larger diameter shafts, but many of them fail quickly due to crappy small bearings as do many of the isis I have seen. The (infinite) ie: (8)-fun has large needle bearing supports in a nice wide supportive housing. For a general purpose system, it is very good. I agree, they will need to make a specific system for the wider / thicker bb shells and can address the jumping crowd then with a heavy large diameter shaft. The isis is not something I would go backwards to as it is quickly becoming obsolete at this point.

 

[rodgah]

does the pedallec sensor know if you are spinning the cranks backwards? or will it power either way?

 

[teslanv]

does the pedallec sensor know if you are spinning the cranks backwards? or will it power either way?

Only powers when pedaling forward.
You can also kill the current by lightly tapping the brakes.

 

[spinningmagnets]

does the pedellec sensor know if you are spinning the cranks backwards?

Yes, the little magnets are paired N/S so the sensor can tell which way it's spinning. There are two pairs, so in 360-degrees of rotation, there are two timed pulses to the computer.

 

[teslanv]

Looks like cell_man is going to start selling the Bafand Mid drives.

http://em3ev.com/store/index.php?route=common/home

These things seem to be taking off...

 

[Kepler]

Cell_man is a smart business man. The BBS02 and his new frame mount battery will be a combo hard to beat. Hopefully he will also provide a custom programming service for the drive or even better, the actual programming software.

 

[Kepler]

Gave the new bike a good shakedown at one of our local single track locations. Bike felt great and performed for the most part very well. however, on really rough terrain i did have some problems with the chain bouncing of the chain ring and falling inwards. This would mainly happen on rough descents with no power on to keep the chain under load.

Came up with a simple chain guide that attaches directly to the drive. Should do the trick I think.

 

[Melbourne]

Gave the new bike a good shakedown at one of our local single track locations. Bike felt great and performed for the most part very well. however, on really rough terrain i did have some problems with the chain bouncing of the chain ring and falling inwards. This would mainly happen on rough descents with no power on to keep the chain under load.

Came up with a simple chain guide that attaches directly to the drive. Should do the trick I think.

Nice work with all the custonizations....wish i had your skills.

 

[deepfraught]

I just noticed that is an elevated chainstay frame as well as compact dual suspension Kepler. My new MAC front build is belt drive so since falling in love with belt drive on top of hub (pedal drive geared hub i should clarify) addiction, my Bafang winter bike dream (not a wet dream is something like that frame for full suspension and fatter tyres in the wet, and still take the EM3EV triangle frame battery as well as not need a frame split to take the belt.

I will be hanging out for cellman's release since no wet weather in sight, have been considering the bottle battery for weatherproof factor combined with the bafang, and as a discrete bike. The 36V 500W with 36V battery fits some more cells than the 48V, and less top speed in poorer weather and dark is a good idea.

 

[Kepler]

I would still stick with the 750W 48V version. In PAS mode, even the highest setting it is not that quick (about 35kph) I personally wouldnt want any less than that. You do of course get more speed with the throttle so it depends if you are happy to use the throttle instead of the PAS.

 

[Kepler]

A little bit of BBS02 action.

[youtube]S04cKOAn3XA[/youtube]

 

[Geebee]

Kepler the video comes up this video is private

All fixed cheers

 

[Kepler]

I forget to change it every time Sorry about that.

 

[deepfraught]

Thanks, I like to run low power for pedal feel like your Wh feedback on the rear hub, but it is nice to be able to flick it up and clear out, plus already have the nice 14S 25Ah triangle frame battery so will burn the 36V idea

 

[deepfraught]

A little bit of BBS02 action.

Is there any BB flex with crank drive on elevated chainstay frame?
When chasing up and finding more older era specs with steel and titanium pedal only frames i found reports of flex common, but weren't rear suspension or MTB examples.

 

[Warren]

Kepler,

"Came up with a simple chain guide that attaches directly to the drive. Should do the trick I think."

I don't have high hopes for your chain guide. Chains don't come off up front. On roadbikes they tend to come off the back of the chainring, where the chain enters the chainring, from whipping side-to-side. On Downhill MTB's they tend to come off the bottom, when the chain leaves the chainring, as the rear derailleur cage swings down/forward on bumps. My guess is the chain will come off the bottom first, and be stopped by your guide. This would allow you to pedal to guide it back on. But sometimes it will come off the bottom half and all the extra slack will whip up around the cassette to the top run of chain, dumping it off the top. Pedaling at that point won't likely pull the chain back up onto the chainring. Notice most DH bikes have the rollers at entry and exit of the chain.

http://www.balleracing.com/MRP/MRPSystem2.jpg

 

[mikelec]

I'm having the same issue with my full suspension bafang drive on rough terrain. When not pedalling over bumps and jumps the chain flaps about and even with the chainline dead straight the chain bounces off the chainring. Most mtb chainguides won't fit this drive I don't think due to the motor mounting.

I've been thinking that a roller or cog mounted on a bracket off the lower swing arm with a little bit of downward tension would held stop the chain coming off the top of the chainring. Maybe the same thing could be done for the lower part of the chain too...

I'm sure there is a product about which will fit the bill, perhaps with some modding.