New Bafang Crank-Drives

[--freeride--]

I have run over 11K miles on a 350 watt mid-drive system. I can tell you that running a through-the-gears drive with torque sensing, or pedalec is a bad idea. None of the torque sensors or pedalecs respond quick enough. For decent shifting performance and chain life you need to back off the throttle going into lower/easier gears. Upshifts are fine at WOT, but downshifts will bust your quick link in short order. I broke a bunch before figuring this out. Haven't broken one in 10K miles since. And for the 750 kit, with IGH's you need to back off the throttle to unload the hub, so it can shift. A torque sensor is just a nuisance with through-the-gear drives. You run WOT all the time and pick the gear that gives you a decent cadence, and the wattage takes care of itself. This is the case for properly designed systems, as this one is. If you under or over volt the unit, without changing the chainring to maintain proper cadence, you will defeat the design.

The new 2014 Bosch drive has got really good sensors (combination torque and PAS) and they are quick enough to ride the bike, like you would use a normal bike. Pedal on with no load for shifting...
I think it will take some more years untill the Chinese get there...

I ordered the 750W version and got a nuvinci sitting here waiting for the motor.

 

[kVAR]

I ordered the 750W version and got a nuvinci sitting here waiting for the motor.

Which nuvinci are you going to use? N360? Autoshift? I am considering doing the same thing (750w with Nuvinci in the rear)

 

[--freeride--]

I ordered the 750W version and got a nuvinci sitting here waiting for the motor.

Which nuvinci are you going to use? N360? Autoshift? I am considering doing the same thing (750w with Nuvinci in the rear)

N360 with manual shifting. I want to do offroad riding. I don`t think the autoshift version is good for that.

 

[Kepler]

Met up with Melbourne this morning who was kind enough to show me his bike and give me a ride to sample the drive's performance.

First impressions:
Visually it is quite small and makes for a reasonably stealthy installation. Having the controller built in keeps the install nice and clean.
Installation looks really simple, probably even more simple than a hub motor install. However, bike selection with a suitable bottom bracket for the drive is very important as there is going to a high percentage of bikes that the drive simply won't fit on to.

The Display is quite a nice looking unit but very basic in relation to the info it provides. Gives speed and distance data plus a battery gauge and assist level. Not a big fan of this type battery gauge as it really is just an indication of what you have left. Would much prefer to see an Ahr or Whr reading on the display.

Riding:
Firstly, yes, it is quiet. As quiet as any electric setup I have ridden except perhaps for my 5405 Stealth Bomber motor.
This is a 350W unit and it feels like 350W which is in no way a criticism. The power delivery is very smooth and I think they have the PAS activation/de activation delay and ramp spot on. Makes for a nice connected riding experience. I think there were 4 PAS settings. It looks like they use a torque simulation strategy for control i.e each level sets a current limit rather than a speed limit. This means you can pedal to the max cut out speed with the various levels of assistance. I prefer this method of PAS and have found that true torque sensing setups only have a minor advantage over this setup.

Melbourne's bike still had the speed limiter but tricked for a max speed of 35kph. Realistically, this is all you are going to get from a 350W system so certainly the speed limit isn't an issue on this bike. It is a bit of shame that that when you trick the speed limit by change wheel diam settings, your speed and distance data is rendered useless.

Gear changing under power:
At 350W, changing gears under power really isnt a major issue from what I experienced. Unfortunately Melbourne's bike did have some selector issues but this could easily be fixed I believe.

Nothing like actually seeing a product in the flesh and being able to test ride it. Conclusion for me is that its full speed ahead with getting one of these kits for my next build. For me however, the 750W kit with speed limiter removed and 48T chainring will be what i will be ordering.

Melbourne. Great to catchup and put a face to a name. Hope you didn't mind me doing a mini review on your setup. Hopefully it will help others watch this thread.

 

[footloose]

Thanks for mini-review.
It is helping me limber up my right arm, which notoriously has difficult reaching for my wallet :wink:

 

[Melbourne]

Melbourne. Great to catchup and put a face to a name. Hope you didn't mind me doing a mini review on your setup. Hopefully it will help others watch this thread.

Not a problem...Its good to get a review from someone with experience in ebikes as i am clueless about ebike. It not often i get to meet a TV star from New Inventors... I remember seeing the episode about friction drive but didn't remember ur face...lol

 

[Samd]

Hi Melbourne, did you get the throttle connected ok?

There is a dearth of other threads over the forum on shifting mid-drives. Similar issues here, and rings many bells with my Aprilia mid-drive experiences. Derailleurs may be the only viable answer with a 750W unit.
Servo+Arduino has always been an appealing solution to try.
http://spectrum.ieee.org/geek-life/hands-on/diy-electronic-bicycle-derailleur

 

[Melbourne]

Thanx Samd

Throttle is working perfectly... i use it as a boost button to catchup with lycras and up hills..

 

[jk1]

Hi Melbourne

350w is just enough for me to commute and keep up the commuting lycras at

but you will be sadly disappointed, its under-powered

Maybe this has something to do with the motor design ? This is a high voltage motor 36v , so to be only 350w the amps and hence torque has to be lower then say a 24v motor as Torque is related to amps . For example comparing this to the most similar motor is the 24v 350w cyclone mid mount motor, they both have the same output power 350w. But the cyclone motor would have more torque as it runs at less voltage and hence more amps and Torque. torque is what you "feel" and need to accelerate or go up steep hills and maybe thats why it feels so week compared to your 250w HUB motor BH bike which sounds unusual ?This would also apply to the 750w version at 48v

 

[Melbourne]

In the right gears bbs01 mostly like have more torque than my BH Neo xtrem... i prefer the bbs01 more than the commercial legal (oz) bike... very stealthy and quiet.

 

[full-throttle]

you will be sadly disappointed, its under-powered compared to your beast. :0

Def not disappointed Its marginally weaker than my commuter.
The drive feels nice. The overall quality is ok for the price. Similar to GNG.
Let's see how long it lasts..

 

[Samd]

I've an old ex-aprilia Shimano megarange cluster in my shed, think it goes from 11-34 teeth. Hoping it will suit my 350w BBS01 unit pretty well. If it ever arrives

Tried to convince GBK to sell me a 750W instead but it looks like someone else from Melb got the jump on their last. Fess up you lot. 8)

I'm never planning to make it replace my juiced up Bafang BPM for offroading. But I'm hoping it makes a good work commuter that I can take on some nice tarmac coated hills. There'll always be room in my shed for a couple of middrives as well as an offroader. Different need states...

 

[Nine]

Very very interesting thread....

I have been riding an ICE power assist bike for 3 years now.

I have a vintage 1989 Gary Fisher CR-7 mountain bike that was simply gathering dust in the basement and I had a long commute to work with a car I could not afford anymore.....and so a search was made into the power assist market....

I looked into the electrics three years ago but decided against them because of range issues.....and it looks like with these new BB motors and with battery technology improving almost daily I am impressed and very impressed with this new bottom bracket crank motor....

I choose a company called GEBE or Golden Eagle Bike Engines a small firm out of Michigan which has a very cool mount system and belt drive mounted to very efficient Japanese micro internal combustion motors....

This motor the Bafang is most astounding as an add on to an existing bicycle in that it provides low weight and a bicycle that still pedals as a bicycle if the motor is not running similar to what my very successful GEBE kit is doing right now.....

I have well over 16000 miles commuting with this system but however am looking to build another bike up with an electric kit and so this was a very interesting thread for sure with very well informed contributors and mostly very high quality posts.


And so with the ICE bikes so the electric bike folks seem to be really concerned with speed and I would suggest that range is a more important issue for the industry....

And so an ICE bike with its liquid fuel bottles as opposed to a lithium stick as a means to store energy ....or human legs like the drug induced Lance Armstrong....its all stored energy converted to forward motion.....maybe I am wrong upon this assumption.....

Well for me it put off buying another vehicle....saving money on gas and insurance and registration fees.....and a bit of exercise for these past there years and its all good.....

A true bicycle is pure simple transportation.....and of course a power assist is very important and most useful and of course at some point it no longer is a bicycle but a motorcycle....and so I look at this simple small efficient motor this Bafang simply like what my GEBE kit has been doing for me and many other folk....

Well really great thread and my interest is hugely spiked....

Nine

 

[Kepler]

I've an old ex-aprilia Shimano megarange cluster in my shed, think it goes from 11-34 teeth. Hoping it will suit my 350w BBS01 unit pretty well. If it ever arrives

Tried to convince GBK to sell me a 750W instead but it looks like someone else from Melb got the jump on their last. Fess up you lot. 8)

I think that would be me Pulled the trigger a few days ago on the BBS02. I will give you a race

I'm never planning to make it replace my juiced up Bafang BPM for offroading. But I'm hoping it makes a good work commuter that I can take on some nice tarmac coated hills. There'll always be room in my shed for a couple of middrives as well as an offroader. Different need states.

It wont replace the Bafang powered Fighter either but it will be interesting to see how it stacks up against the Super Commuter. Mine will be going into another hard tail 29er but with an aluminium frame this time so it will be a very similar platform, just a couple of Kg heavier.

 

[t3sla]

I've an old ex-aprilia Shimano megarange cluster in my shed, think it goes from 11-34 teeth. Hoping it will suit my 350w BBS01 unit pretty well. If it ever arrives

Tried to convince GBK to sell me a 750W instead but it looks like someone else from Melb got the jump on their last. Fess up you lot. 8)

I think that would be me Pulled the trigger a few days ago on the BBS02. I will give you a race

Already selling out
There is a decent backlog.... couple of months until orders can be filled

The irony of it all is bosch is to blame, a delay causing increase demand and a subsequent delay...... :lol:
http://www.bike-eu.com/Home/General/2013/10/Bosch-Struggles-with-Delivery-Problems-1390570W/

Guess that's what happens when you make a good product

 

[speedmd]

The BBS02 arrived safely, well boxed in a custom foam pack. Extremely nice looking unit. Game changer compared to the gng kit. The bar went up in a big way folks! At least for a commuter setup. Bosch was never even a slight consideration in my plans. You would need to cut up or buy a specific frame for it. I would not be surprised if this out sold bosch 1000 to 1. Need a custom Battery box now. Always a catch with this stuff.

 

[spinningmagnets]

If you Google "Bafang BBS02", the electricbike.com article and the Endless-sphere.com thread are both near the top on the first page. From what lectriccyles.com has said, Bafang was aggressive marketing the 250W drive in Europe and Asia, but the 750W version was something they sort-of 'reluctantly' agreed to 'try out'.

If Canada still has a 500W power limit for a street-legal E-bikes, Bafang is likely to amp-restrict the built-in controller on the 750W unit, rather than try to up-rate the slightly shorter 250W motor. I'd say that's good news for Canadians. The motor will be the same as the 750W, and MWKeefer said it's easy to run an external 6-FET to allow Canadians to have what "looks like" a legal set-up.

 

[Rollodo]

Ok spinningmagnets, thanks for the earlier explanation about the 350W vs 750W kV values, it was helpful. However, I still have a question about power consumption, and the choice of the battery depends on the answer. You said earlier (I believe you did, but I can't find it now, of course) that they both will be drawing the same amps on the flat. If that's the case, the 48V motor will still consume more Watts out of the battery pack - the pack will deplete faster. If I get the 36V motor and it draws 10 Amps (consuming 360W) out of a 36V 15Ah pack (540Wh), after 1 hour I still have ~30% juice left before the pack depletes (360W). If 48V motor draws the same 10 Amps (consuming 480W) out of the 48V 15Ah pack (720Wh), I only ... wait, I still have ~30% to go before the 48V one depletes, too. But the 48V is bigger, heavier, more expensive, not more useful on the flats, why did I post this?

 

[DaveTheWave]

they both will be drawing the same amps on the flat. If that's the case, the 48V motor will still consume more Watts out of the battery pack - the pack will deplete faster.

I'm just a newbie here and am probably wrong so I'm hoping someone can help me understand this better than I do at present. With respect to the Bafang 350, 500, and 750 watt options, It would seem to me if we compare two bikes that are identical other than having different voltage motors, and both are moving at the same speed over the same course, both would consume the amount of same power (watts) but not the same current (amps).

We know that Power (watts) = Volts x Amps. So if one bike with a 48V motor needed to burn 100 watts to maintain a given speed on a flat level course, it would have to consume a steady flow of current of 2.08 amps since 100W divided by 48V = 2.08A. And an identical bike with a 36v motor, would also need to burn 100 watts to maintain same speed on same course. But since watts= volts*amps, and the voltage is lower, it would need to consumer more current, specifically 2.77 amps.

A 48v 10AH battery would contain more power (480 Watt-Hours) than a 36V 10AH battery (360 Watt-Hours) and so it should have a greater range, all other things being equal. Two batteries of different voltages but having the same power, (for example a 48v 10AH battery vs. a 36v 13.3AH battery, both having 480 Watt-Hours) should provide the same riding range (assuming both are feeding a motor that is properly matched to the voltage, and all other things being equal). I have not tested this personally.

Does this make sense - or do I have it all mixed up?

 

[Rollodo]

they both will be drawing the same amps on the flat. If that's the case, the 48V motor will still consume more Watts out of the battery pack - the pack will deplete faster.

I'm just a newbie here and am probably wrong so I'm hoping someone can help me understand this better than I do at present. It would seem to me if we compare two bikes that are identical other than having different voltage motors, and both are moving at the same speed over the same course, we would find that both would consume the amount of same power (watts) but not the same current (amps).

We know that Power (watts) = Volts x Amps. So if one bike with a 48V motor needed to burn 100 watts to maintain a given speed on a flat level course, it would have to consume a steady flow of current of 2.08 amps since 100W divided by 48V = 2.08A. And an identical bike with a 36v motor, would also need to burn 100 watts to maintain same speed on same course. But since watts= volts*amps, and the voltage is lower, it would need to consumer more current, specifically 2.77 amps.

A 48v 10AH battery would contain more power (480 Watt-Hours) than a 36V 10AH battery (360 Watt-Hours) and so it should have a greater range, all other things being equal. Two batteries of different voltages but having the same power, (for example a 48v 10AH battery vs. a 36v 13.3AH battery, both having 480 Watt-Hours) should provide the same riding range (assuming both are feeding a motor that is properly matched to the voltage, and all other things being equal). I have not tested this personally.

Does this make sense - or do I have it all mixed up?

I want to understand this, too.

 

[gknowes]

ok I'm a newbie also all things are not equal. if 36v at 10a =360wh thin 48v at 7.5 a = 360wh wright ?

 

[bose]

Will it be possible to replace the chainring with a smaller one in respect to the drive axle coming out from the motor? On pictures it looks as if it could be tight with space for the chain if the chainring edge lines up with the motor drive axle.

 

[jerrypa]

I have looking around the 250W 36V newest system. How i can be sure that i am buying newest model?
Any links to sellers how ship it pretty fast to EU?

 

[Kepler]

they both will be drawing the same amps on the flat. If that's the case, the 48V motor will still consume more Watts out of the battery pack - the pack will deplete faster.

I'm just a newbie here and am probably wrong so I'm hoping someone can help me understand this better than I do at present. With respect to the Bafang 350, 500, and 750 watt options, It would seem to me if we compare two bikes that are identical other than having different voltage motors, and both are moving at the same speed over the same course, both would consume the amount of same power (watts) but not the same current (amps).

We know that Power (watts) = Volts x Amps. So if one bike with a 48V motor needed to burn 100 watts to maintain a given speed on a flat level course, it would have to consume a steady flow of current of 2.08 amps since 100W divided by 48V = 2.08A. And an identical bike with a 36v motor, would also need to burn 100 watts to maintain same speed on same course. But since watts= volts*amps, and the voltage is lower, it would need to consumer more current, specifically 2.77 amps.

A 48v 10AH battery would contain more power (480 Watt-Hours) than a 36V 10AH battery (360 Watt-Hours) and so it should have a greater range, all other things being equal. Two batteries of different voltages but having the same power, (for example a 48v 10AH battery vs. a 36v 13.3AH battery, both having 480 Watt-Hours) should provide the same riding range (assuming both are feeding a motor that is properly matched to the voltage, and all other things being equal). I have not tested this personally.

Does this make sense - or do I have it all mixed up?

Your assumption is correct. If both batteries have the same Whr capacity they will provide very similar range assuming the two setups are traveling at a similar speed and have a motor kv optimised for that speed.

In the case of this drive, I believe the BBS02 has a lower motor kv then BBS01 to keep the motor in its efficiency sweetspot at 48V. The BBS01 which is a 36V setup would be interesting overvolted to 48V providing you can get the speed limiter removed.

 

[Kepler]

I have looking around the 250W 36V newest system. How i can be sure that i am buying newest model?
Any links to sellers how ship it pretty fast to EU?

I think there are only 2 models. The BB01 and the BBS02. The BBS01 is for 36V and comes seems to be available in Wattages from to 250W to 350W. The BBS02 is for 48V and seems to be available for in Wattages from 500W to 750W.