BBS02 report from Las Vegas Energie Cycles

Interesting read,
http://www.energiecycles.com/#!news/c12oa
Clearing Up The Facts About The BBS-02 Mid-Drive System
Product Development Team - April 2014

In our trip to Shanghai for the China Cycle show, we made a side trip to our strategic motor partner Bafang in Suzhou. There are few companies in this industry that have the facility size and capacity to produce and deliver more than 800,000 units annually.

We had a full agenda with the engineering team to get our staff fully prepared to sell, install, service and customize the Bafang BBS-02 mid-drive motor systems. With our own engineering team present, we wanted to address the various stories out there regarding the motors and the debate behind the two types of drives.

BBS-01 Overheating Issues - It was reported that the original motors in the 500 and 750 watt capacity were overheating and failing. FACT: the motor controllers did have an issue and yes the production stopped for a short period of time but there were two solutions. The immediate solution was to temporarily reduce the peak amp from 25 to 22 to keep the drives from shutting down. The more permanent solution (which is now in place) is that the controller has been upgraded to include 9 FETs over the previous 6 FETs (MOSFET). This will allow a greater amp output without overheating. This was actually a similar issue with the separate controllers and hub motors in the early days when the increased motor sizes where introduced.

The latest version of the larger drives known as BBS-02 for the 500 and 750 watt systems are in full production and shipping now.

Cancellation of the 500 watt 36volt system - In one blog, it was stated that Bafang was going to stop making this 500 watt model for 36volt systems. FACT: no this is not true. An updated controller is also being installed in this version for better and cooler performance and will be part of the BBS-02 program and it too is shipping right now.

Warranty And Overall Life Cycle Of Bafang Motors - Another motor manufacturer had lumped Bafang into a specific category that associated it with the typical domestic quality products often found in China. FACT: In our research of international users the quality seems to be holding up. To start with like our own warranty policies, Bafang offers a full 2-year warranty on the parts inside.

As for longevity, one example of life cycle is a company in Europe that has a fleet of hub powered bikes that deliver 2 large propane tanks on every run up and down hills. These bikes have been operating without motor issues for more than 4 years. In France the postal service has 20,000 hub powered electric bikes used daily for delivery and are now into 5 years on their systems without any reported warranty issues.

If there are any issues with the nylon/delrin gears, engineers demonstrated the easy replacement option that can be done by a typical e-bike mechanic.

The new mid-drive system gears are also replaceable but in the 2 years of development and evaluation there have been no reported warranty issues on the gear systems.

Torque Output - Other experts have claimed that the new mid-drives cannot deliver the published torque output. FACT: with our own engineers present in the lab, we took random motors from our current order and ran tests to show the measurement. Both our 500 and 750 units exceeded the printed amount. We saw 86Nm for the 500 and 94Nm for the 750 at peak outputs. When converted to Foot Pounds, the 500 watt delivers 63.43 ft lbs and the 750 equals 69.34 ft lbs!

For reference, our typical 500 watt brushless hub drive delivers around 20Nm which is equal to 14.75 ft lbs.

In further evidence that all mid-drives are creating increased torque for the benefit of both the higher weight of cargo bikes as well as the new trend in mountain bike configurations, Bosch reported chain failure early on, which has brought on the demand for higher tension chains. Energie Cycles has already announced that our new Bafang mid-drive solutions will come with the new e-bike chain that offers 10x the strength.

This sound like a desperate attempt from a chinese corporation to gain back market shares after a sudden drop in sales.
Maybe they are trying to liquidate the current model ?
I've been burned by chineses company before. Never again.

Am I the only the who refrained from ordering one after hearing about the potential issues ?
I'm in a "wait and see" mode. It's a shame, because summer is coming and all I have is a slow Bionx

Haha. It's called Chinese progression. Build first. Sell it to smithereens. Wait for the problems. Then fix the problems. Repeat. Sometimes insert "take another person's idea" as the first step.

But that's a little harsh on the Chinese, and I'm probably being stereotypical. I'm probably sure the good companies do R&D before the final product hit the shelves.

Seriously? You're either living in bubbles or you've never owned a range of cars, scooters, bicycles, or even toasters. Recalls are not limited to Chinese products. I got lucky and think I got the second generation BBS01. But early adopters of many things mechanical suffer the same issues. My $6000 Vespa scooter had a leaky exhaust gasket that burned brake lines. My sisters Ford burst into flames for some owners who were rear ended. The list is massive. Your experience is limited. Then there's all the American companies that are peddling "American made". Any idea just what that means? It means someone in the USA put the pieces together regardless of where the bits were manufactured. Last season I bought a cast iron lawn furniture set and payed a premium for "made in the USA". It was expensive. When it arrived the boxes referenced the number of boxes per case and number of cases per container. When I confronted the company the said, oops!, we usually put them together and sell them, in which case we meet the guidelines. Of course I won that battle and kept the table AND a full refund. IMO it may all comes down to who you bought your unit from. My next will come from lactic cycles. The extra $150 over EM3ev is worth having support. The addition $100 to EM3ev is a better bet than any other China based reseller. (The frustration of 3-4 days for support finally broke my back.) I'm convinced Bafang is a straight up company, but buying from the grey market in China may well be a buyer beware situation. I'm willing to bet lowballs are going to sell out old stock. People will continue to get 6fet controller rather than the updated 9fet. 25 years of working for bookmakers and gamblers makes those odds very attractive from my perspective. So, again from my n00b perspective, go ahead and buy an American made E Bike. Oh wait, they're made from unobtanium! Kinda reminds me of the guys driving the little Ford trucks of years ago. One guy I knew had a bumper sticker on his the said something about buying foreign cars and putting ten Americans out of work. Clueless that his Ford was entirely Japanese, built in Japan. It's a global market and we're on the bleeding edge.

tomjasz said:

Interesting read,
http://www.energiecycles.com/#!news/c12oa
Clearing Up The Facts About The BBS-02 Mid-Drive System

BBS-01 Overheating Issues - It was reported that the original motors in the 500 and 750 watt capacity were overheating and failing. FACT: the motor controllers did have an issue and yes the production stopped for a short period of time but there were two solutions. The immediate solution was to temporarily reduce the peak amp from 25 to 22 to keep the drives from shutting down. The more permanent solution (which is now in place) is that the controller has been upgraded to include 9 FETs over the previous 6 FETs (MOSFET). This will allow a greater amp output without overheating. This was actually a similar issue with the separate controllers and hub motors in the early days when the increased motor sizes where introduced.

Click to expand...

Yes - interesting read. Thanks for posting. I'd like to see some more detail on the mid/hub comparisons in particular.

Just for the record, I did find the initial statement about 'BBB-01' overheating a bit confusing. I'd thought it was the larger 500 & 750 watt motors on 48v that were reported as getting hot and needing a temp cutout which I understand was eventually fitted.

I also have never heard of a BBS01 36v 750w model mentioned above! Maybe this is how the controllers for the earliest versions of the BBS01 were configured before they went to a larger stator for the higher power/voltage model?

eM3ev also had quite a clear summery of what Bafang were up to in his news page on April 11th.

savvas

tomjasz, Nice report, thank you for the info. Wish you luck in your ventures.

This is good news, and I will add it to the electricbike.com article. In the interests of full disclosure, I have not owned a BBS02. However, when I first read about them, I felt they were a much-needed milestone in an often ignored user-profile...and I felt they needed a wider exposure. I would like to now express a few thoughts about this new information:

All of the optional controllers (6-FET: 15A, 18A, 20A, 25A) will "bolt up" to any BBS-series housing. Wholesalers in various countries can specify any combination of voltage or amperage that suits their local customers and laws.

The BBS01 labeled housings have the narrower stator and the Kv of the motor (its turn count) is adjusted to provide the same RPMs at the lower voltage, this is so the mechanical part can be the same for both variations.

The BBS02 labeled housings have a stator that is 10mm wider (with the accompanying extra copper mass). Not much of a difference, but every bit helps in a motor this small. The Kv is as stated before...adjusted so that at 48V, the BBS02 motor spins at the same RPMs as the BBS01/36V.

Upgrading the 6-FETs in the controllers to 9 FETs will allow the controllers to run cooler, but will not affect the heat in the motor stators. The symptom of the drive overheating would be that the heat-protection circuits would cut power until the drive had cooled off. Any damage that occurs would be a warranty item, because the heat protection should be adequate to prevent any heat damage.

The controller FETs and the motor stators (the hot parts) are adequately bonded to the stock aluminum housing, and in fact...the bike frame itself will absorb some of the housing heat. The 500W version of the 36V BBS01...and the 750W version of the 48V BBS02...both use the 25A controller. Per the stated posts above, if any rider has the older 6-FET controller, they would be wise to use the bikes controller to limit the power to 22A.

Since the stock controller and motor are inside the same housing, the act of bypassing the stock controller to use an external controller would allow the entire heat-sinking ability of the aluminum housing to be used exclusively by the motor. The Lyen 6-FET with authentic, efficient, and cool-running 3077 FETs can easily supply 30A. If you try this, please closely monitor the motor temps, and apply the throttle with moderation...at least until there is more data, and the next weakest internal part is identified (from being broken by an ES member).

tomjasz said:

Torque Output - Other experts have claimed that the new mid-drives cannot deliver the published torque output. FACT: with our own engineers present in the lab, we took random motors from our current order and ran tests to show the measurement. Both our 500 and 750 units exceeded the printed amount. We saw 86Nm for the 500 and 94Nm for the 750 at peak outputs. When converted to Foot Pounds, the 500 watt delivers 63.43 ft lbs and the 750 equals 69.34 ft lbs!

For reference, our typical 500 watt brushless hub drive delivers around 20Nm which is equal to 14.75 ft lbs.

Click to expand...

Sounds like this is a measurement of crank output power, not what hits the wheel. This is leaving out a critical factor. The bicycle's gears will reduce this figure from 1.5:1 - 4:1.

With a 4:1 gear reduction from the crank to the wheel ( 40T on the crank, 10T on the wheel ), this drive would be producing 17.25 ft-lbs.

Just a FYI unless nobody else caught that one

Anyway, this is very useful info otherwise, thanks a bunch for posting it !

tomjasz said:

Then there's all the American companies that are peddling "American made". Any idea just what that means? It means someone in the USA put the pieces together regardless of where the bits were manufactured.

Click to expand...

http://www.endless-sphere.com/forums/viewtopic.php?f=7&t=42806

a 6 FET overheating at 500 to 750W ? seriously ?

Lebowski said:

a 6 FET overheating at 500 to 750W ? seriously ?

Click to expand...

Remember that 750W is the rated wattage. Max watts would be voltage x 25A. For my 12S battery @ 50V HOC, that's 1200W. And the controller is nested right in with the motor, so there's that.

One also has to consider that a mid drive is far more likely to be used continuously close to it's power rating than a hub, where you will typically only see peak loads during acceleration or hill climbing, but time is allowed to cool off while cruising.

neptronix said:

One also has to consider that a mid drive is far more likely to be used continuously close to it's power rating than a hub, where you will typically only see peak loads during acceleration or hill climbing, but time is allowed to cool off while cruising.

Click to expand...

Only thing is the Mid drive will be much more efficient for the hills, especially the steepest of hills and the slow hilly trails.

The Bosch can climb mental hills and still be hardly warm to the touch, I'm sure inside is warm but it never trips the temp cut off.

On level ground a dd or geared hub will most likely be more efficient, to be honest there won't be much in it.

The Bosch is very efficient for a 500 watt motor, it can climb @ 500 watts (and a lot of hard pedalling) what a high torque magic pie can at 3kw and pedalling) the difference the pie will cook, I dare not take the 8T mac even at 500 watts up 20-23% grades. Perhaps a 12 T would be a much different story.

I will admit for normal use the 8T mac is a great motor and will climb decent hills very fast and much faster than the Bosch if you want not to pedal and go fast, the Mac is a great motor and will climb @2kw 10-12% no problem.

If I were to go the hub motor route again I'd probably opt for the mac 12T, as long as I could get 25 mph I'd be happy, I'm not interested in speed any more, been there done that got to 40 mph, Now I'm more interesting in just using the motor for assistance and the Bosch sure suits me well.

neptronix said:

tomjasz said:

Torque Output - Other experts have claimed that the new mid-drives cannot deliver the published torque output. FACT: with our own engineers present in the lab, we took random motors from our current order and ran tests to show the measurement. Both our 500 and 750 units exceeded the printed amount. We saw 86Nm for the 500 and 94Nm for the 750 at peak outputs. When converted to Foot Pounds, the 500 watt delivers 63.43 ft lbs and the 750 equals 69.34 ft lbs!

For reference, our typical 500 watt brushless hub drive delivers around 20Nm which is equal to 14.75 ft lbs.

Click to expand...

Sounds like this is a measurement of crank output power, not what hits the wheel. This is leaving out a critical factor. The bicycle's gears will reduce this figure from 1.5:1 - 4:1.

With a 4:1 gear reduction from the crank to the wheel ( 40T on the crank, 10T on the wheel ), this drive would be producing 17.25 ft-lbs.

Just a FYI unless nobody else caught that one

Anyway, this is very useful info otherwise, thanks a bunch for posting it !

Click to expand...

True, but if you're using those gears, you want pure speed so you don't need the torque. I think the point is you can still get very high torque using low gear reduction, which is beneficial for the hills. I mean, that's the biggest reason to get a mid-drive anyway versus a hub motor.