MAC vs Bafang

[Arbol]

Is this true? Is the Bafang BPM better than MAC/BMC for smallish wheels

It depends, some controllers have an electrical RPM limit. what voltage do you want to run, what turn-count of motor will you use (its kV), and what controller do you hope to use?

Here are links to teardowns of the MAC and Bafang-BPM, with lots of pics of the guts:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=51313

I am still learning, and I still do not know enough about turn-count to be able to answer your question.

I am doubting between a BPM/MAC/... style of motor, with 48V and say 30A (which would be linked to a LiFePO4 30A/60A; the controller would probably be a 9 FET IRFB 3077 one, capable of 30A), or a Direct Drive with probably a bit higher power (say 72V 65A, which is what I have read is the max a 9C will accept; this would require lipos, for example 3 packages of 6s 5000 mAh 20C; the controller would probably be a 18 FET IRFB 4110 one, capable of 60A).

I have read about the differences between the two, but I am still undecided.

Usage:

1. European city, quite hilly. About 15km to 20km per day (but half is downward, so I will rarely need the motor for half of the path). Lots of traffic lights, stop and go. Probably a 250w motor would do.
2. Trekking along the coast, non-pavement roads, but in relative good condition. Also probably a 250w would do (I do that without a motor right now)
3. Trekking through the hills / mountains. This is something I have not done so far without a motor, because it is "too much" for me without a motor (ideally, I would like to do 50km to 60km). Here, there would be the clear advantage of a motor (with a big battery, for sure, but I would pedal quite strongly, too)

The MAC has the advantage of being lighter and better suited for stop and go, which are strong pluses for the urban usage. But I have read the MAC may be unreliable (vs the 9C) for off-road usage. So the 9C appears to win in the reliability camp (in addition to the fact one can run higher power with the 9C rather than with the MAC). Also, the 9C seems better suited for light batteries (lipo), which also can provide a higher amperage. For urban usage, if I need to leave the bike parked in the street for a few minutes, there is an advantage of only having to carry with me a few lipos than a big LiFePO4 battery.

So, I am undecided.

Any opinions from people with a direct experience on these products? Thanks!

 

[d8veh]

Most people here seem to be comparing the Bafang BPM with the MAC. Greenspark's comments are very valid: things have moved on at Bafang, and we now have the 500w CST motor. It isn't just a BPM with a cassette spline. They completely re-engineered the motor. The build quality inside is, to me, a step-change from the BPM and Mac. I've not heard of a single problem reported with it yet, and most important of all, that cassette spline allows you to have proper quality gearing.

And if that's not enough, there's the Xofo clone of the CST. It's a slightly slower wind and a bit cheaper, but it seems to run equally well if not better. I had mine at 64v and 30 amps and it didn't complain. Good for 30mph like that. I don't know whether it's the same as the CST inside: Xofo claim that they improved it.

MXUS also make a clone of the Bafang CST, but I haven't tried it yet.

 

[Arbol]

Most people here seem to be comparing the Bafang BPM with the MAC. Greenspark's comments are very valid: things have moved on at Bafang, and we now have the 500w CST motor. It isn't just a BPM with a cassette spline. They completely re-engineered the motor. The build quality inside is, to me, a step-change from the BPM and Mac. I've not heard of a single problem reported with it yet, and most important of all, that cassette spline allows you to have proper quality gearing.

And if that's not enough, there's the Xofo clone of the CST. It's a slightly slower wind and a bit cheaper, but it seems to run equally well if not better. I had mine at 64v and 30 amps and it didn't complain. Good for 30mph like that. I don't know whether it's the same as the CST inside: Xofo claim that they improved it.

MXUS also make a clone of the Bafang CST, but I haven't tried it yet.

Interesting, thanks. It seems the CST is ideal: robust, light and it accepts high power.

I have been looking around, and I only can find a CST (36V) at BMSbattery. Is there another webpage to buy either the CST or the Xofo? I am based in Europe, but I could buy elsewhere.

 

[greenspark]

I am a bit surprised about the price differential. Not because the absolute difference (do $100 to $200 matter in the overall picture here?) but the relative difference: one is almost double the price of the other. And OK, the MAC is lighter and better for stop an go, but the DD is more robust and accepts more power. So, at least from a theoretical point of view, without having tried any of them, it is not obvious which is best.

Price is determined by the manufacturer, not Cell Man. We have noticed that the Chinese appear to charge more for newer motors, and lower the price on older designs, thus a Bafang BPM kit is listed on another site as $170 while the newer Bafang CST kit is $306. It is not that the CST is twice as good, it is the recovery of the capital investment and the market willing to pay a premium for it, that drives the price.

"Best" depends on what you are trying to do... what use and what appearance. If you live on a 2nd floor walk-up apartment, like to have the ebike component of your bicycle looking "stealth" (i.e subtle and not noticed), like to run longer on a charge, and prefer to pedal on the flat and use the motor as an assist going up a hill, then the geared motor (MAC) is "best". If you park in a garage, never lift the bike, either don't have far to go on a charge or buy a larger battery, and you want your bicycle to be more moped-like, then the DD is "best". See http://e-bikekit.com/ebike-kits/electric-bike-motor for a useful explanation. BTW, from what we see, the issue of complexity no longer translates to longevity as MAC motors (and others) are well made.

I am still learning, and I still do not know enough about turn-count to be able to answer your question.

"Turn" has an engineering explanation and a functional one. It refers to the number of copper windings, where functionally the higher the turn number (12T vs 10T) means more torque and less top speed. If you live in a flat area and want a motor to carry you along at a speed comparable to a moped or motorbike, you want lower T count. In contrast if you are climbing hills you want a higher T count. Of course, this then also interacts with the diameter of the tyre/rim/wheel, which is another variable to consider, and it is further complicated by the voltage of the battery and the amount of current the controller allows the battery and the throttle to feed the motor. Finally, a rider (as opposed to an engineer) is not interested in the engineering calculations or numbers, but the experience: functionality vs cost.

On this forum there are a wide range of interests, thus advice will depend on how aligned your interest is with the member giving an answer. Consider some of the different rider/applications:

• flat land, weak knees, bikes into village to shop (a 180W Euro pedalec is fine with a standard controller and a small 36V battery)
• hilly land, weak knees, bikes into nearby village to shop (a 250W Euro higher-t pedalec should do it but with a thumb throttle as well, standard controller and small 36v battery)
• commuter decides to stop driving 20 km commute to work, bikes with some hills, wants to be able to ride at 50kph (30 mph) to keep up with city car traffic [if legal] (a big 52v battery 500W MAC 10T motor w. 9 fet 30A controller*)
• electronic enthusiast (ebike engineer or geek) wants the most powerful motor he can find, and intends to program the controller, shunt and generally push the envelope (no recommendations, they know what they want)
• off road hill climber wants the most powerful kit he can find (no recommendation, too much liability in giving advice) See http://www.youtube.com/watch?v=FJsMDsT8siU

*The commuter may also want an easily detachable battery so he can carry it into work and charge it under his desk for the ride home.

 

[Arbol]

I am a bit surprised about the price differential. Not because the absolute difference (do $100 to $200 matter in the overall picture here?) but the relative difference: one is almost double the price of the other. And OK, the MAC is lighter and better for stop an go, but the DD is more robust and accepts more power. So, at least from a theoretical point of view, without having tried any of them, it is not obvious which is best.

Price is determined by the manufacturer, not Cell Man. We have noticed that the Chinese appear to charge more for newer motors, and lower the price on older designs, thus a Bafang BPM kit is listed on another site as $170 while the newer Bafang CST kit is $306. It is not that the CST is twice as good, it is the recovery of the capital investment and the market willing to pay a premium for it, that drives the price.

"Best" depends on what you are trying to do... what use and what appearance. If you live on a 2nd floor walk-up apartment, like to have the ebike component of your bicycle looking "stealth" (i.e subtle and not noticed), like to run longer on a charge, and prefer to pedal on the flat and use the motor as an assist going up a hill, then the geared motor (MAC) is "best". If you park in a garage, never lift the bike, either don't have far to go on a charge or buy a larger battery, and you want your bicycle to be more moped-like, then the DD is "best". See http://e-bikekit.com/ebike-kits/electric-bike-motor for a useful explanation. BTW, from what we see, the issue of complexity no longer translates to longevity as MAC motors (and others) are well made.

I am still learning, and I still do not know enough about turn-count to be able to answer your question.

"Turn" has an engineering explanation and a functional one. It refers to the number of copper windings, where functionally the higher the turn number (12T vs 10T) means more torque and less top speed. If you live in a flat area and want a motor to carry you along at a speed comparable to a moped or motorbike, you want lower T count. In contrast if you are climbing hills you want a higher T count. Of course, this then also interacts with the diameter of the tyre/rim/wheel, which is another variable to consider, and it is further complicated by the voltage of the battery and the amount of current the controller allows the battery and the throttle to feed the motor. Finally, a rider (as opposed to an engineer) is not interested in the engineering calculations or numbers, but the experience: functionality vs cost.

On this forum there are a wide range of interests, thus advice will depend on how aligned your interest is with the member giving an answer. Consider some of the different rider/applications:

• flat land, weak knees, bikes into village to shop (a 180W Euro pedalec is fine with a standard controller and a small 36V battery)
• hilly land, weak knees, bikes into nearby village to shop (a 250W Euro higher-t pedalec should do it but with a thumb throttle as well, standard controller and small 36v battery)
• commuter decides to stop driving 20 km commute to work, bikes with some hills, wants to be able to ride at 50kph (30 mph) to keep up with city car traffic [if legal] (a big 52v battery 500W MAC 10T motor w. 9 fet 30A controller*)
• electronic enthusiast (ebike engineer or geek) wants the most powerful motor he can find, and intends to program the controller, shunt and generally push the envelope (no recommendations, they know what they want)
• off road hill climber wants the most powerful kit he can find (no recommendation, too much liability in giving advice) See http://www.youtube.com/watch?v=FJsMDsT8siU

*The commuter may also want an easily detachable battery so he can carry it into work and charge it under his desk for the ride home.

Wow, this forum is great, thank you for the detailed explanation.

Regarding all your comments, it is clear to me I need a (reliable) geared motor, ie either a cell_man's MAC or (I believe you are also implying this) a BPM CST.

Clearly, I am on the

"[*]commuter decides to stop driving 20 km commute to work, bikes with some hills, wants to be able to ride at 50kph (30 mph) to keep up with city car traffic [if legal] (a big 52v battery 500W MAC 10T motor w. 9 fet 30A controller*)"

option (with a relatively high turn; I do not care much about speed, I care about acceleration and ability to go up hill).

May I ask your inputs on "*The commuter may also want an easily detachable battery so he can carry it into work and charge it under his desk for the ride home", please?

In fact, 30 seconds before reading your post, I have written another thread going on these lines:

http://endless-sphere.com/forums/viewtopic.php?f=3&t=52125

I am still deciding what to do, but now I am considering a 26'' foldable bike (eg Tern Joe C21 or P24), since I could trek with it (I do not really need a MTB / DH), it would be relatively comfortable, and I could fold it and take it with me indoors, instead of parking it in the street. However, from time to time I would need to park the bike say 30 minutes on the street, and I would like some kind of safety for the battery, so I am looking at batteries with a case and a lock (of course, the bike would be locked, too, with an Abus or something similar).

 

[greenspark]

Most people here seem to be comparing the Bafang BPM with the MAC. Greenspark's comments are very valid: things have moved on at Bafang, and we now have the 500w CST motor. It isn't just a BPM with a cassette spline. They completely re-engineered the motor. The build quality inside is, to me, a step-change from the BPM and Mac. I've not heard of a single problem reported with it yet, and most important of all, that cassette spline allows you to have proper quality gearing

Interesting, thanks. It seems the CST is ideal: robust, light and it accepts high power.

I have been looking around, and I only can find a CST (36V) at BMSbattery. Is there another webpage to buy either the CST or the Xofo? I am based in Europe, but I could buy elsewhere.

We have both the MAC and two CST units, one 12T one 14T 36V. The first difference is the cluster. MAC takes a spin on, CST takes the cassette type. MAC provides a good cluster that has a smaller small gear so you can keep pedalling at speed. If you want to change gear ratios, with a cassette you can do so, with the older spin-on type you don't. However, in real life most folks install the cluster and that is the end of it, so its more a matter of whatever your bike comes with, or if you buy from Cell Man, have him pop one in the box.

The CST is smoother and less powerful. The MAC is slightly beefier feeling, and has more grunt. Not sure what makes the difference, but again, it's subtle. For CST think Pierce Brosnan as James Bond; for MAC think Daniel Craig. I should note that the CST was hooked up to the Bafang Z01 controller after we found something in three K1200 controllers was conflicting with the BMS whereas the MAC runs on an Infineon controller that Paul set up. Bafang does not make it easy to program their controllers (you would need to hack them on your own); Paul sells a cable to hook the Infineon up to a laptop. Are you beginning to see the difference between MAC/Paul and Bafang yet?

If you are based in Europe, your first consideration (presuming you will use your motor on the public road) is to ask if being legal is important or not. MAC is for enthusiasts - 350 and 500W, CST offers a 250W Euro-legal version that gives decent power.

To find vendors for the CST Google Bafang cst motor and you will find most of the usual vendors, not just BMS battery. Most recently we used http://www.greenbikekit.com/index.php/electric-bike-kit-1/rear/8fun-cst-e-bike-kits-36v-250w-350watts.html and like them. However, your big question will have to do with shipping. We can't help wondering if the low-priced Chinese vendors are not earning their profit on the shipping charges. The costs range wildly and can be substantial; if you order the kit with a laced 700C or 26" wheel, the bulk increases the price. When we put an order in with BMSbattery and selected a shipper and paid, they then came back to say that option was not available, and we owed them more money. The same happened with ecitypower.com. The only one who seems to pay attention to shipping is Paul (Cell Man) who can offer surface shipping that takes longer but saves a bundle. However, he offers MAC not CST. His batteries by the way are excellent... more expensive but worth it.

Another option to consider: the mid-engine. When we were in Suzhou in January Bafang invited us to hop onto a test bike with their new BBS01 crank motor. In March, we took delivery of two to test, a 350W detuned to 300W (to be legal here) and a Euro 250W (except that it also had a thumb throttle, which is legal here). We installed them on standard bikes; first a Bella Ciao, and last week put the 250W on a 1951 Raleigh DL1. We think they are fantastic to the point that in NZ we are now recommending them over hub motors.

Installation is simple: one removes the cranks, BB and chain ring, and slips in the BBS01 kit motor that comes with its own 46 or 48 tooth chainring. The controller is built in to the unit. See http://szbaf.com/product.asp?id=22. Also Google will find a number of German videos showing them. Bafang pays a lot of attention to Europe.

Since the motor drives the chainring, it uses the bikes rear gears, so a lower-powered motor can torque you up a steep slope the same way a lower gear on a car or motorcycle does. It is smooth, quiet and uncluttered. It also is fairly subtle. It is ideal for a derailleur cluster that can be shifted while pedalling. On a Shimano Nexus (Bella Ciao) or a Sturmey Archer S3X (Raleigh) we have to stop the motor before shifting by lightly holding the ebrake handle, or we need to plan ahead so we are not needing to shift whilst under power.

It appears that it was inspired by a Japanese motor (almost identical looking), but it does appear that in 2013 Bafang is taking advantage of automation to put out some fairly good product. We read that they recently introduced a 750W version as well. Not sure who is offering them for sale, but here is one on eBay DE http://kleinanzeigen.ebay.de/anzeigen/s-anzeige/bafang-8fun-bbs01-kurbelantrieb-motor-pedelec/131662332-217-8599?ref=search

The good news is that in July 2013, there is more choice than there was a year ago. The bad news is that it requires more research to sort out what you want.

 

[greenspark]

am still deciding what to do, but now I am considering a 26'' foldable bike (eg Tern Joe C21 or P24), since I could trek with it (I do not really need a MTB / DH), it would be relatively comfortable, and I could fold it and take it with me indoors, instead of parking it in the street. However, from time to time I would need to park the bike say 30 minutes on the street, and I would like some kind of safety for the battery, so I am looking at batteries with a case and a lock (of course, the bike would be locked, too, with an Abus or something similar).

We had a battery made up by Cell Man that we keep in a Brooks Millbrook saddle bag. No one knows there is a battery in there and we keep a dirty rag on top of it. Camouflage is always better than temptation. A thief who knows a battery is valuable, will figure out how to steal it. Better to use stealth.

From what you are describing, I think you are better placing the whole order with Paul (Cell Man). He will work with you, provide the right setup and give you guidance.

You would be better off with having Paul design the battery to fit in something like a locking pannier or handlebar bag in which you hide the battery, or if you live in a high-risk area have him buy a military surplus ammo case (or send him one) and ask him to fit the his battery inside of it. Then have it bolted onto the frame with theft-proof bolts.
See picture:
Paul can very the configuration size of batteries as well as build you whatever size you need (more cells = more distance). If you want to be Euro legal, he will sell you a 500W or 350W motor but then set the controller to 250W to keep the EuroCops happy.

In regard to folding bikes, we installed the MAC on a Montague Crosstown which is a folding 700C bike, but find the wheels too big. If you are going folding, buy a Brompton. http://lovelybike.blogspot.co.nz/2012/06/brompton-owners-impression.html and http://lovelybike.blogspot.co.nz/2012/05/off-road-on-edge-of-world.html

 

[Arbol]

Paul can very the configuration size of batteries as well as build you whatever size you need (more cells = more distance).

Here there is something I do not understand:

From:

http://em3ev.com/store/index.php?route=product/product&path=35&product_id=106

Paul says:

"Our 16S 20Ah A123 Battery Pack uses the High Power and High Energy Density A123 AMP20, 3.3V, 20Ah Nanophosphate Lithium Ion Prismatic Pouch Cell"

So, cells are 20Ah. This is consistent with the battery being a 52.8V, with 3.3V cells: there are 16 cells in each battery.

So, it is not obvious I may have a smaller battery (always assuming 48V, approx.), since a smaller battery implies less voltage, not less "ability to run distance" (the Ah, if I understand correctly).

The ideal would be to have a 52V 20Ah battery divided into two parts: one with say one quarter of the capacity, another one with the remaining three quarters. The first one would be for city usage (not too many km, quite light to carry on), the other one would be added for weekend, longer trips.

In fact, I had thought about this just yesterday, looking the 8-piece Headway BMS of BMSbattery, but I realized the 8-piece BMS for say 38120 was not to do a 48V 4.5Ah (16 pieces give 48V 9Ah), but the opposite, 24V 9Ah.

Can this be done?

 

[spinningmagnets]

I have read of quite a few riders who purchased two of the 10-Ah battery packs, so that there was an even weight distribution in panniers. I do not like the combined weight of the motor and large battery pack both being in the rear. It works, but feels worrysome at higher speeds. The geared motors are not very heavy, and if you can put your main battery pack in the triangle, that seems to provide a fairly well-balanced "feel" when riding.

There have been several builders who mounted their pack in the front-basket position, and the reports of the bikes handling have reassured me that this mounting position would work well for a "long ride" add-on pack, but I have no experience yet with that.

edit:

The MAC is slightly beefier feeling, and has more grunt. Not sure what makes the difference

The magnets and stator teeth on the MAC are 25% wider than the BPM (22mm vs 17mm)

 

[Arbol]

I have read of quite a few riders who purchased two of the 10-Ah battery packs, so that there was an even weight distribution in panniers. I do not like the combined weight of the motor and large battery pack both being in the rear. It works, but feels worrysome at higher speeds. The geared motors are not very heavy, and if you can put your main battery pack in the triangle, that seems to provide a fairly well-balanced "feel" when riding.

There have been several builders who mounted their pack in the front-basket position, and the reports of the bikes handling have reassured me that this mounting position would work well for a "long ride" add-on pack, but I have no experience yet with that.

Mmm your comment has suggested me an idea. When you are talking about a the battery being in the front-basket position, are you thinking about a Wald 137 type of front basket? That could be stealthy.

 

[docnjoj]

Where can the Bafang "middle motor" be purchased? It seems like a great idea if it is relatively easy to install.
otherDoc

 

[spinningmagnets]

I have read good reports about the Bafang BBS01 BB-drive, but it is listed as a 350W. My new favorite commuter is the GNG-Gen2 with LightningRods new bracket, using 36V X 25A = 900W. I haven't had the opportunity to pull apart a Gen2, but it clearly has more copper mass than the Bafang BBS01, which is designed for Europe and Asia, and their markets have much lower power limits.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=45740&start=200#p772781

 

[docnjoj]

I have read good reports about the Bafang BBS01 BB-drive, but it is listed as a 350W. My new favorite commuter is the GNG-Gen2 with LightningRods new bracket, using 36V X 25A = 900W. I haven't had the opportunity to pull apart a Gen2, but it clearly has more copper mass than the Bafang BBS01, whic is designed for Europe and Asia, and their markets have much lower power limits.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=45740&start=200#p772781

Thanks for the info S/M. We run a max of 20 mph and mostly a bit less on our bike paths. They are MUT and have dog walkers and runnersand also gardeners and lawn care folks parking on th path so speed ain't such a good idea. The paths are parallel and adjacent to a 50mph road with 2 waytraffic, so occasionally we need to go out into it to get around "obstacles". My only requirement is quiet motors, so we run 9C's now. The Bafang looks a lot better engineered than the GNG.
otherDoc

 

[greenspark]

I have read good reports about the Bafang BBS01 BB-drive, but it is listed as a 350W.

We are running both a 250W Euro-spec and a 350W that we asked be detuned to 300W to comply with our law. I can assure you both 250W and 350W exist. I expect that the difference is in the controller settings built in to the motor. I need to set aside some time and try them both out one after the other, so I can see what the real-life difference feels like.

 

[greenspark]

Where can the Bafang "middle motor" be purchased? It seems like a great idea if it is relatively easy to install.
otherDoc

At this point, my contact with the factory is exceptionally busy. However, I expect that sources will come on line soon.

 

[Architectonic]

Any opinions from people with a direct experience on these products? Thanks!

MAC feels more like a bike as it freewheels, but is not up to hard off-roading IMO. The problem is not the gears either, those are actually very reliable now. The problem is the clutch and the keyway, which I suspect wears quickly when riding off road.

I would actually recommend a 9c/crystallyte and set it up either pedelec style or with a torque sensor (Cycle Analyst v3 is a must either way), instead of a throttle - if you want it to feel like a bike that is.

 

[Arbol]

Any opinions from people with a direct experience on these products? Thanks!

MAC feels more like a bike as it freewheels, but is not up to hard off-roading IMO. The problem is not the gears either, those are actually very reliable now. The problem is the clutch and the keyway, which I suspect wears quickly when riding off road.

I would actually recommend a 9c/crystallyte and set it up either pedelec style or with a torque sensor (Cycle Analyst v3 is a must either way), instead of a throttle - if you want it to feel like a bike that is.

Thanks. I only have tried gearless motors (q100, for example) so I do not really understand what do you mean by a 9c "not feeling like a bike". I see many people say something similar, so that must be true. Why are gearless motors working more like a bike, rather than the direct drives (9c / crystallyte / ...)? I have read there is some friction with the DD even when off, is it that?

 

[d8veh]

The CST is smoother and less powerful. The MAC is slightly beefier feeling, and has more grunt. Not sure what makes the difference, but again, it's subtle. For CST think Pierce Brosnan as James Bond; for MAC think Daniel Craig. I should note that the CST was hooked up to the Bafang Z01 controller after we found something in three K1200 controllers was conflicting with the BMS whereas the MAC runs on an Infineon controller that Paul set up. Bafang does not make it easy to program their controllers (you would need to hack them on your own); Paul sells a cable to hook the Infineon up to a laptop. Are you beginning to see the difference between MAC/Paul and Bafang yet?

The Bafang Z01 controller is 15 amps max according to their website, so i'm not surprised that you notice a power difference from Paul's 25 amp controllers with the MAC. We run our 500w CSTs with 30 amp controllers, Which makes them a lot more powerful than what you experienced, and IIRC from a previous thread, you had the 250-350w version of the CST, not the 500w one. The lower powered version doesn't respond well to more amps for whatever reason, so even if you used a 25 amp controller, it's still not very powerful. You have to compare like with like to get a true comparison, which means the same controller and battery, and the 500w version of the CST.

I think you missed the advantages of the cassette spline too. It's not about changing clusters, it's about which clusters you can fit. You need 11T top gear on an electric bike if you want to pedal. You can get free-wheel clusters with 11T top gear but they're poor quality and hard to find. With a cassette spline, 11T top-gears are readily available, and you can get whatever quality of gears you want.

 

[Arbol]

The CST is smoother and less powerful. The MAC is slightly beefier feeling, and has more grunt. Not sure what makes the difference, but again, it's subtle. For CST think Pierce Brosnan as James Bond; for MAC think Daniel Craig. I should note that the CST was hooked up to the Bafang Z01 controller after we found something in three K1200 controllers was conflicting with the BMS whereas the MAC runs on an Infineon controller that Paul set up. Bafang does not make it easy to program their controllers (you would need to hack them on your own); Paul sells a cable to hook the Infineon up to a laptop. Are you beginning to see the difference between MAC/Paul and Bafang yet?

The Bafang Z01 controller is 15 amps max according to their website, so i'm not surprised that you notice a power difference from Paul's 25 amp controllers with the MAC. We run our 500w CSTs with 30 amp controllers, Which makes them a lot more powerful than what you experienced, and IIRC from a previous thread, you had the 250-350w version of the CST, not the 500w one. The lower powered version doesn't respond well to more amps for whatever reason, so even if you used a 25 amp controller, it's still not very powerful. You have to compare like with like to get a true comparison, which means the same controller and battery, and the 500w version of the CST.

I think you missed the advantages of the cassette spline too. It's not about changing clusters, it's about which clusters you can fit. You need 11T top gear on an electric bike if you want to pedal. You can get free-wheel clusters with 11T top gear but they're poor quality and hard to find. With a cassette spline, 11T top-gears are readily available, and you can get whatever quality of gears you want.

When you use the 500W CST with a 30A controller, I believe you are getting 1.08kW (36V * 30A). What is the best type of battery providing these 30A? I see quite a few LiFePO4 batteries providing 15A of continuous amperage, and 30A of max (supposedly available only for short periods of time). With an added option, one may get 30A / 60A BMS for those batteries. Which of the two type of BMS would be best for a 500W CST and a 30A controller? Or you are using another type of battery (eg lipo)? Thanks.

 

[greenspark]

Or you are using another type of battery (eg lipo)? Thanks.

On that one, I bought the complete kit from Paul (Cell Man). He made a triangle A123 Battery that fit into a bag in the frame. He first discussed via email my options, and then he set everything up for me. Given your interest, it seems that is the best combination of advice and custom design at an affordable price. Best to correspond with him through his web site.

In the end, we sold that kit and the Gary Fisher hardtail on which it was installed because it clearly was too much bike for our requirements. The buyer had a 20 K commute into the city and wanted a 50kph ride on a strong frame. He intended to charge the battery whilst at work, although it probably was big enough to get him home without recharging if he did some pedalling. It had the rear gear cluster that Paul supplied with an 11 tooth gear so at 50kph, pedalling still worked. With the original 14 tooth cluster at 50 kph one could not keep up with the pedalling, and a police officer would know it was an illegal moped. At least when the rider is pedalling, it looks less strange.

 

[d8veh]

When you use the 500W CST with a 30A controller, I believe you are getting 1.08kW (36V * 30A). What is the best type of battery providing these 30A? I see quite a few LiFePO4 batteries providing 15A of continuous amperage, and 30A of max (supposedly available only for short periods of time). With an added option, one may get 30A / 60A BMS for those batteries. Which of the two type of BMS would be best for a 500W CST and a 30A controller? Or you are using another type of battery (eg lipo)? Thanks.

We use this one which seems to cope quite well. I've had this combination for a year now on my main bike. It's only when going up steep hills that you'll see maximum current (30 amps). At speed, the back EMF from the motor cuts the current down to about 15 to 20 amps depending on how fast you're going. I'm not sure that the rating given by BMSBattery is correct. A 20aH battery can easily give 20 amps continuous, unless it's a rating for the BMS. We have some very long steep hills, and the BMS has never cut-off.
http://www.bmsbattery.com/36v/445-36v-15ah-lithium-ion-electric-bicycle-battery-pack.html

 

[Architectonic]

Why are gearless motors working more like a bike, rather than the direct drives (9c / crystallyte / ...)? I have read there is some friction with the DD even when off, is it that?

A geared/clutched motor will freewheel, whereas a direct drive motor will have drag which is caused by the back emf generated by the motor. This means it can be used for regen braking though, whereas that isn't possible with a freewheeling motor.

 

[greenspark]

A geared/clutched motor will freewheel, whereas a direct drive motor will have drag which is caused by the back emf generated by the motor. This means it can be used for regen braking though, whereas that isn't possible with a freewheeling motor.

Before seeing regen as a feature, best to read this excellent analysis and discussion: http://www.endless-sphere.com/forums/viewtopic.php?f=16&t=9045. Regen extends range only by 5-10% because bikes and riders are so light; there is not a lot of energy to capture when slowing them down (this is why you can stop with some rubber clamping pressing on rims as opposed to the much larger brakes required to stop a car, or a Harley). The tradeoff is that pedalling without the motor helping adds a molasses feeling to the pedalling.

So once again, it comes down to the desired experience. If you want to enjoy classic bicycling, where pedalling moves you about four times walking speed, but going up hills you want some help rather than being so low geared that you feel like you are down to walking speed, then you want a geared motor or you want a direct drive that has a clutch to disengage it when pedalling. If you plan to have the motor assist all the time, then a direct drive can serve the purpose... although I predict in time that the direct drive will be eclipsed by more sophisticated and durable-designed geared motors.

 

[Arbol]

I have read good reports about the Bafang BBS01 BB-drive, but it is listed as a 350W.

We are running both a 250W Euro-spec and a 350W that we asked be detuned to 300W to comply with our law. I can assure you both 250W and 350W exist. I expect that the difference is in the controller settings built in to the motor. I need to set aside some time and try them both out one after the other, so I can see what the real-life difference feels like.

You said "I expect that the difference is in the controller settings built in to the motor". Have you been able to check this info? Is the 250W the same as the 350W, just with different controller settings? If so, could these settings be changed from the 250W to the 350W? Thanks.

 

[greenspark]

I have read good reports about the Bafang BBS01 BB-drive, but it is listed as a 350W.

We are running both a 250W Euro-spec and a 350W that we asked be detuned to 300W to comply with our law. I can assure you both 250W and 350W exist. I expect that the difference is in the controller settings built in to the motor. I need to set aside some time and try them both out one after the other, so I can see what the real-life difference feels like.

You said "I expect that the difference is in the controller settings built in to the motor". Have you been able to check this info? Is the 250W the same as the 350W, just with different controller settings? If so, could these settings be changed from the 250W to the 350W? Thanks.

I have not checked the info, and to get into the controller, I would need access. Bafang is most reluctant to provide instructions on how to do this, unlike Cell Man (Paul) who provides a cable specifically to enable owners to program his Infineon controllers. As I am not an electrician, I would not know how to proceed. It would be good if someone else who was technically proficient could get one of the units and try it out. Hackers needed.

Having said that, now that the 250W is running on the 1951 Raleigh DL1 and the detuned 300W on the Bella Ciao, we really can't tell much difference. Remember that both drive the 3-speed internal hub (one a Shimano Nexus, the other a SA S3X), thus going up hills, we use the lower gears, and then on the flats use the higher gears. Like a car, this allows a broader range of power assist than if we used a hub motor that does not take advantage of the gearing. It is a completely different experience.