New Bafang Crank-Drives
- Thread starter d8veh
- Start date
crossbreak
1 MW
--freeride-- said:
nope, wont fit. Derailleur cage is too short. Even the 36T dont fit all derailleurs.
"nope, wont fit. Derailleur cage is too short. Even the 36T dont fit all derailleurs."
I have not kept up with derailleur developments, but several years ago there were rear derailleurs that had cages long enough to wrap 45 teeth worth of chain. Is that no longer the case? With a single front chainring, most long cage derailleurs designed for multiple front chainrings should be able to handle 11-44. Of course, the jockey pulley needs to be low enough, with the tension pulley all the way forward, to clear the biggest rear cog. This might be the problem.
I have not kept up with derailleur developments, but several years ago there were rear derailleurs that had cages long enough to wrap 45 teeth worth of chain. Is that no longer the case? With a single front chainring, most long cage derailleurs designed for multiple front chainrings should be able to handle 11-44. Of course, the jockey pulley needs to be low enough, with the tension pulley all the way forward, to clear the biggest rear cog. This might be the problem.
crossbreak
1 MW
"cage" was the wrong term.... "jockey pulley" i did not know that word 
that one sits too close to the wheel center.
that one sits too close to the wheel center.--freeride--
100 W
- Joined
- Jul 5, 2011
- Messages
- 237
crossbreak said:"cage" was the wrong term.... "jockey pulley" i did not know that word
There are still several detaileur (shimano and Sram) that fitt a 42T or could be modded with a longer scew. So no rocketscience to do that mod.
crossbreak
1 MW
interesting. can't find this 42T custom sprocket, do you have a link for us?
--freeride--
100 W
- Joined
- Jul 5, 2011
- Messages
- 237
I only got this link to a very long thread in the german mtb-news Forum that discusses custom XX1 Mods:
http://www.mtb-news.de/forum/showthread.php?t=601751&page=70
The 42T Chainwheels for the rear are produced by a guy in the forum. So you might better look for a solution in your local forum.
There are although aftermarket solutions available:
http://www.i-mtb.com/general-lee-40t-cassette-adaptor-shimano/
http://www.mtb-news.de/forum/showthread.php?t=601751&page=70
The 42T Chainwheels for the rear are produced by a guy in the forum. So you might better look for a solution in your local forum.
There are although aftermarket solutions available:
http://www.i-mtb.com/general-lee-40t-cassette-adaptor-shimano/
crossbreak
1 MW
General Lee Kassettenadapter 25-40z is at 120€
seems like forum member "mirfe" sells a single 42T cheaper. http://www.mtb-news.de/forum/member.php?u=114430
seems like forum member "mirfe" sells a single 42T cheaper. http://www.mtb-news.de/forum/member.php?u=114430
http://www.ebay.com/itm/41-Tooth-Cog-for-Mountain-Bike-Cassette-41t-Sprocket/251324151982?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D1588027615987621723%26pid%3D100011%26prg%3D1005%26rk%3D5%26rkt%3D5%26sd%3D251243702528%26
crossbreak
1 MW
nice find for people who are in the US.
I'll order the 42t from the MTB forum member, my cassette consists of a 9-speed HG61 12-36+42T sprocket but without the 12t, so 14-16-18-21-24-28-32-36-42
Hope this will be durable with the 2000W continuous output power my motor has. With this large cassette and Hammerschmidt overdrive gearbox I can have chain tensions below 2500N. Sadly the hammerschmidt does not work with the 750W bafang units. Still, this cassette is also worth thinking about with this 750W unit IMO, since it will eat the smaller gears/chain in frequent use. The HG61 12-36T cassette really deserves an "e-bike capable". With 300% spread almost any hill can be climbed even without pedaling.
The HG 50 13-34T 7-speed cassette is also a cost effective solution, much more durable than the 11-32T cassettes that are commonly used, especially with the cheap 804 connex chain. It's the best off-the shelf 7-speed cassette for middrives IMO. The 260% is more than enough for people who dont need to climb 20% hills every day. Stay away from the 14-34 "Megarange" 7-speed cassettes. They have nasty gear steps.
Maybe some forum member can make larger 52T chainrings or adapters for this bafang unit. It deserves a more durable drivetrain, lower chain tension/higher chainspeed is always a good thing.
BTW I had problems with some 7-speed front chainrings with the 9-speed shimano chains. Seems they dont really fit. The SRAM 9-speed works flawlessly since 1000km+ now. The Connex/Wippermann 9-speed 908 seem to work as well on 7speed/2.00mm wide chainrings.
I'll order the 42t from the MTB forum member, my cassette consists of a 9-speed HG61 12-36+42T sprocket but without the 12t, so 14-16-18-21-24-28-32-36-42
Hope this will be durable with the 2000W continuous output power my motor has. With this large cassette and Hammerschmidt overdrive gearbox I can have chain tensions below 2500N. Sadly the hammerschmidt does not work with the 750W bafang units. Still, this cassette is also worth thinking about with this 750W unit IMO, since it will eat the smaller gears/chain in frequent use. The HG61 12-36T cassette really deserves an "e-bike capable". With 300% spread almost any hill can be climbed even without pedaling.
The HG 50 13-34T 7-speed cassette is also a cost effective solution, much more durable than the 11-32T cassettes that are commonly used, especially with the cheap 804 connex chain. It's the best off-the shelf 7-speed cassette for middrives IMO. The 260% is more than enough for people who dont need to climb 20% hills every day. Stay away from the 14-34 "Megarange" 7-speed cassettes. They have nasty gear steps.
Maybe some forum member can make larger 52T chainrings or adapters for this bafang unit. It deserves a more durable drivetrain, lower chain tension/higher chainspeed is always a good thing.
BTW I had problems with some 7-speed front chainrings with the 9-speed shimano chains. Seems they dont really fit. The SRAM 9-speed works flawlessly since 1000km+ now. The Connex/Wippermann 9-speed 908 seem to work as well on 7speed/2.00mm wide chainrings.
Easy-peasy!
http://mrbill.homeip.net/albums/stokemonkey_and_ping_battery/pages/page_1.html
This LHT doesn't have one because more than one chainring is pretty pointless, unless you are talking about a cargo bike. But it would still fit, and a triple chainnring too.
http://mrbill.homeip.net/albums/stokemonkey_and_ping_battery/pages/page_1.html
This LHT doesn't have one because more than one chainring is pretty pointless, unless you are talking about a cargo bike. But it would still fit, and a triple chainnring too.
http://gebattery.en.alibaba.com/pro...e_motor_eletric_bike_kit_conversion_kits.html
p.s. sorta off track, but i am seeing here that this baby has a sine wave controller... that explains it's quietude
p.s. sorta off track, but i am seeing here that this baby has a sine wave controller... that explains it's quietude
nukezero
10 kW
Hi Everyone. This weekend, I successfully converted my girlfriend's Electra Townie 21 speed with the Bafang BBS-01 Mid drive kit 36V 350watt 18A from GBK.
Introduction
It took me about 4-5 hours to do it, since I wanted to take the time and had to watch youtube videos on how to remove crank, bottom bracket, and spent some good time cleaning up the wiring as best I could.
Initial Impressions
I'm going to use my production e-bike Motiv 48V Bafang BPM as a comparison. But put it simply, the power delivery is SIMPLY amazing. If I could say the Bafang BPM is like having a Mustang GT's grunt, then the BBS-01 is more like having an Inline-6 cylinder power delivery. Extremely quiet, almost too quiet! Very stealthy and amazing ride quality. Unlike the Bafang BPM where it has a surge off the line, the BBS-01 feels like it delivers an even torque band. I was able to achieve 35km/h or ~21mph (14T).
We rode today for 4 hours at Huntington Beach, CA and had zero issues. Funny to see her chain and chain-ring moving while her feet weren't pedaling.
I am using 40 pcs of Samsung 18650 3.6V 2600mAh ICR18650-26F SDI cells with a BMS. The battery is 36V 10.4Ah. The total battery weight is an amazing 4.5lbs. We did about 12 miles and drained from 43V to 38V. The Bafang LCD interprets this as 3/4 bars (75%).
Issues
There are some issues I wanted to mention however:
1. The kit initially came with PAS always enabled. There didn't seem to be a way to disable this feature. My girlfriend doesn't really like PAS and only wants power on demand via throttle. So after reading someone post that the BBS-01 is nothing more than just a hub motor with PAS technology, I figured that there is probably a sensor in there to disable. SO I opened the motor up and turns out that the PAS is connected to the controller via a 4-wire connector. Once I pulled off this connector, PAS was fully disabled!! The throttle still works and the LCD doesn't generated any errors! Yay!
2. The LCD initally kept saying ERR21 on the bench. I thought I got a dud. Error 21 is not mentioned in the manual. Turns out ERR 21 is caused by the LCD computer not detecting the speed sensor. So I guess you must have it hooked up with the magnet. Although the throttle will work, but the LCD will stop responding (except power off) when an error occurs.
2.5 The speed sensor mount is not adequate. It is too small and too far and I had to add a bracket to get it closer to the spokes.
3. I did not have any issue with some people mentioning that the bottom bracket will have play and destroy the bb threads. Once the motor was mounted with just the bracket, it was pretty sturdy. After tightening the lock-rings very tightly, I didn't see how it would be possble for the motor shaft to have any play at all inside the bottom bracket. It was locked and seem extremely well designed.
4. There isn't much drivetrain shock at all. Probably because this is 36V and I had disabled the PAS. With the PAS, it is a big problem because the motor will kick on and you can't control the speed. it is like PAS going full throttle to the designated max/speed setting in the LCD. So all in all, it seemed safe to change gears while throttling 50% but maybe best not do it at full throttle max speed setting.
5. Left hand e-brake is broken. Not sure what to do. These cheap Wuxing brake levers are disappointing, even my girlfriend noticed that they seemed a bit low quality.
6. I'm using Anderson power poles to connect the motor and battery together. This is the only part where it isn't water proof. The manual showed that it came with cylindrically sealed connectors for the battery, but I did not see this harness at all. The motor came with butt connectors which I cut off and soldered Andersons on it. I don't know how long or how well Andersons can last in environments of humidity, beach weather, etc.
Overall, I'm extremely happy with this conversion. I did use her as a guinea pig and I'm quite jealous now. I think I will be riding her bike around town for fun. It is amazing when shifting gears results in increasing speed. Feels like a motorcycle. I am now considering buying a quality road bike with a high gear and cassette count (10 speed, 11T) and putting on a 48V mid drive kit. I'm am seriously sold on this piece of technology. No more hub motors for me. Crank drives are heck of a lot more fun.
Introduction
It took me about 4-5 hours to do it, since I wanted to take the time and had to watch youtube videos on how to remove crank, bottom bracket, and spent some good time cleaning up the wiring as best I could.
Initial Impressions
I'm going to use my production e-bike Motiv 48V Bafang BPM as a comparison. But put it simply, the power delivery is SIMPLY amazing. If I could say the Bafang BPM is like having a Mustang GT's grunt, then the BBS-01 is more like having an Inline-6 cylinder power delivery. Extremely quiet, almost too quiet! Very stealthy and amazing ride quality. Unlike the Bafang BPM where it has a surge off the line, the BBS-01 feels like it delivers an even torque band. I was able to achieve 35km/h or ~21mph (14T).
We rode today for 4 hours at Huntington Beach, CA and had zero issues. Funny to see her chain and chain-ring moving while her feet weren't pedaling.
I am using 40 pcs of Samsung 18650 3.6V 2600mAh ICR18650-26F SDI cells with a BMS. The battery is 36V 10.4Ah. The total battery weight is an amazing 4.5lbs. We did about 12 miles and drained from 43V to 38V. The Bafang LCD interprets this as 3/4 bars (75%).
Issues
There are some issues I wanted to mention however:
1. The kit initially came with PAS always enabled. There didn't seem to be a way to disable this feature. My girlfriend doesn't really like PAS and only wants power on demand via throttle. So after reading someone post that the BBS-01 is nothing more than just a hub motor with PAS technology, I figured that there is probably a sensor in there to disable. SO I opened the motor up and turns out that the PAS is connected to the controller via a 4-wire connector. Once I pulled off this connector, PAS was fully disabled!! The throttle still works and the LCD doesn't generated any errors! Yay!
2. The LCD initally kept saying ERR21 on the bench. I thought I got a dud. Error 21 is not mentioned in the manual. Turns out ERR 21 is caused by the LCD computer not detecting the speed sensor. So I guess you must have it hooked up with the magnet. Although the throttle will work, but the LCD will stop responding (except power off) when an error occurs.
2.5 The speed sensor mount is not adequate. It is too small and too far and I had to add a bracket to get it closer to the spokes.
3. I did not have any issue with some people mentioning that the bottom bracket will have play and destroy the bb threads. Once the motor was mounted with just the bracket, it was pretty sturdy. After tightening the lock-rings very tightly, I didn't see how it would be possble for the motor shaft to have any play at all inside the bottom bracket. It was locked and seem extremely well designed.
4. There isn't much drivetrain shock at all. Probably because this is 36V and I had disabled the PAS. With the PAS, it is a big problem because the motor will kick on and you can't control the speed. it is like PAS going full throttle to the designated max/speed setting in the LCD. So all in all, it seemed safe to change gears while throttling 50% but maybe best not do it at full throttle max speed setting.
5. Left hand e-brake is broken. Not sure what to do. These cheap Wuxing brake levers are disappointing, even my girlfriend noticed that they seemed a bit low quality.
6. I'm using Anderson power poles to connect the motor and battery together. This is the only part where it isn't water proof. The manual showed that it came with cylindrically sealed connectors for the battery, but I did not see this harness at all. The motor came with butt connectors which I cut off and soldered Andersons on it. I don't know how long or how well Andersons can last in environments of humidity, beach weather, etc.
Overall, I'm extremely happy with this conversion. I did use her as a guinea pig and I'm quite jealous now. I think I will be riding her bike around town for fun. It is amazing when shifting gears results in increasing speed. Feels like a motorcycle. I am now considering buying a quality road bike with a high gear and cassette count (10 speed, 11T) and putting on a 48V mid drive kit. I'm am seriously sold on this piece of technology. No more hub motors for me. Crank drives are heck of a lot more fun.
Attachments
crossbreak
1 MW
Looks like this is a 26" bike, so wheel speed should be around 290rpm.. . The stock chainring is 46T? SO I guess you use the 46/14 = 3.28 overdrive... that is a reasonable crank cadence of 88rpm. This all sound really well designed to me. With a 46/11 reduction you could have better top speed (around 40kph) but also a lot chain wear. Maybe the the CS-HG 13-34T 7speed cassette is something for your girlfriend
Thanks for sharing your experience
wojtek
100 kW
how did this motor cope in terms of temperature? any overheating issues?
nukezero
10 kW
Melbourne said:Nice review... nukezero.
I am suprise you only got 35km/h... BBS-01 reseller is claiming 40-45km/h for 350w36v.
Is you chainring 46T...so 48T will get closer to 40km/h
ps... is the lcd removable?
The Electra Townie comes with 3 chain rings. 28T, 38T, and 48T. My gf always bikes in 38T typically. The BBS-01 uses 44T I think. My girlfriend did notice and complain she had to use more effort to bike now. I did not feel it was that bad, but I did notice her rear brakes were rubbing a bit. That could explain the extra load maybe. I was not pedaling at all! The top speed it reached, no pedaling is 35km/h.
The LCD is not removable at all. It has a philips screw to hold it in. This was a concern for my girlfriend and I and we both thought that it could be stolen, especially if biking in LA or Venice Beach (bike theft capital of southern california). I will think of an alternative way to resolve this. The plus is that the connector is short so it can be quickly detached if the LCD was easily removable. The problem is that without the LCD, it is game over until a LCD replacement is found.
crossbreak said:Looks like this is a 26" bike, so wheel speed should be around 290rpm.. . The stock chainring is 46T? SO I guess you use the 46/14 = 3.28 overdrive... that is a reasonable crank cadence of 88rpm. This all sound really well designed to me. With a 46/11 reduction you could have better top speed (around 40kph) but also a lot chain wear. Maybe the the CS-HG 13-34T 7speed cassette is something for your girlfriend
Thanks for sharing your experience
Warren said:
This is a 26" bike, originally 21 speed. It uses a rear freewheel Shimano MF-TZ31 Tourney 14-34T. I am 155lbs. When using the tallest gear, 14T, the display was telling me 35km/h on flat road. So I convert that to 21.74 MPH. It wasn't as fast as my Motiv BPM which does 26mph, but I do know it certainly hit at least 20mph. I was not pedaling!
The motor did get considerably warmer during my rash and dash around town myself. Unlike the Bafang BPM where it generally remains cool, it was strange that the bbs-01 did warm up. But while my girlfriend was riding it at the beach, it was cold.wojtek said:
Warren said:
Your guess is correct. It is a freewheel MF-TZ31 freewheel 14-34T. Yes, if I upgrade to the MF-HG37 freewheel, then I might gain an extra 1 mph or so top speed. But my gf is not a speed monster, she barely went 23 km/h that day and gets freaked out. But now I'm happy that she can keep up with me more, especially on some inclines. She totally loves it!
I saw the video of the GNG chain driven and that thing is so loud. The bbs-01 is no where near that loud. At the beach, nobody noticed that it was electric much. The battery bag looked too small for most people and the motor is hard to see on her drive-side. So the only give-away is when people see the wire-looms I had.
BTW, someone mentioned that the 48V 750w is not that impressive than just the 48V 350watt or something. But if the 36V/350w can do 21mph (14T), then I reckon that the 48V/750w should bring you up close to 30mph easily, especially with a 11T in the back. My only gripe is that hopefully Bafang will come with various sized chainrings because I think the 44T is maybe a tad too large. 38T may be the sweet spot for my girlfriend. It also doesn't seem that hard to fabricate a custom chainring for this.
Here are some more pictures.
Attachments
wojtek
100 kW
thanks! i was wondering if this would be good enough for light off road? thinking about the 48v 750w
I suspect the reason you could tell the motor was warm is because you could actually put you hand on it. With the geared hub motor, you a feeling the outer aluminum hub shell, not the motor.
Part of the problem for a manufacturer offering different chainring options is that people would need to know what they are doing. As it is, if you ride around in high gear without pedaling, all the time, you will cook the motor on big hills, unless they have thermal protection.
If you ran a high enough gear, you could be pulling the full 18 amps at very low motor speeds...basically turning it into a toaster oven.
Part of the problem for a manufacturer offering different chainring options is that people would need to know what they are doing. As it is, if you ride around in high gear without pedaling, all the time, you will cook the motor on big hills, unless they have thermal protection.
If you ran a high enough gear, you could be pulling the full 18 amps at very low motor speeds...basically turning it into a toaster oven.
wojtek
100 kW
there must be a way to force cool this motor... maybe add air cooling using powerful 120mm fans or something
maybe add air cooling using powerful 120mm fans or somethingThe 48 volt, 25 amp, "750" can already pull over 1200 watts out of a battery, and possibly 1000 watts through the chain. A one kWh pack won't even get you 30 miles at that rate, and unless you run a BMX chain to a IGH, you will be replacing chains at a ridiculous rate. But over-stressing/breaking stuff seems to be a hobby for many on this site.
This is a really nice e-assist setup. Wanting to deliberately screw it up is lost on me.
This is a really nice e-assist setup. Wanting to deliberately screw it up is lost on me.
