Review of my Bafang BBS02 500W/36V kit

bgt

Finding my (electric) wheels
Jun 3, 2015
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74
The Netherlands
After using a 250W BBS01 kit I swapped to a 500W kit. Easy if all the parts except the motor stay the same.
I modified my Batavus Mamboo to an ebike and it took a lot of finetuning to get it the way I want. The pull and speed are awesome. I use an Italian 42T chainwheel for a perfect chainline, Chainglider chainguard, heavier rollerbrakes/chain, double batteries(36V) which I assemble myself(Dolphin=14.5Ah) using Panasonic 18650PF (50)cells(carrier battery is a Lifepo4/10Ah), small relay switchover box, Schwalbe ebike tyres, Suntour SP12-NCX seat suspension. Topspeed.....40-50km/h(depending on headwind, controller is set at max=60km/h). Tyre pressure 5.5 bar.
https://dl.dropboxusercontent.com/u/11003205/Batavus Mamboo3.jpg
Controller is set to "current" mode and 100% "speed". PAS mode is set at max. 56% support and thumbthrottle at max.100%.
Please feel free to ask me specifics!!
 
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bgt

Finding my (electric) wheels
Jun 3, 2015
11
0
74
The Netherlands
Nice build Bert de Groot.

The alcedoitalia.it 42t chainring is certainly one of the more useful mods available for the Bafang BBSxx's.
Thanx, yes the original Bafang chainwheel was awfull for the chainline and gave a lot of grinding noises and broken chainrings/chain. There is sooo much power here:)(900 Watts peak)
I am now looking at a Xofo MMT250/500W (with torque sensor)to built but the people at Xofo are a bit too vague about chainline issues. So I am still discussing this with them. If the Italian 42T chainring does not fit its useless.
http://www.xofomotor.com/ProductsAllZ3.asp?id=162&Str=CENTRAL-MOTOR
 
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Fordulike

Esteemed Pedelecer
Feb 26, 2010
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bgt

Finding my (electric) wheels
Jun 3, 2015
11
0
74
The Netherlands
If the fixing bolts do not align with the motor, then you may be able to drill new holes in the chainring to fit.It would take some fine measurements to get it right, but doable ;)
That Xofo does look suspiciously similar to the Bafang though.Copyright infringement perhaps? Not that the Chinese really care lol :p
The Xofo guy has been a former Bafang employe so yes, it looks very similar.
Taking the risk of not being able to fit the chainring is not a pleasant thing. Just a waist of money. Chainline alignment is too important with these powers.
 

chain

Pedelecer
Jul 14, 2011
56
4
I use an Italian 42T chainwheel for a perfect chainline,
I found that by inserting spacers between the drive side of the motor/bottom bracket unit and the end the end of the BB shell on my Utopia Kranich, I got a perfect 54mm Rohloff chainline. Then I fitted Bafang's 44T chainring, for which you can get a Rolloff-compatible Chainglider, and the Hebie Chainglider. The Chainglider is essential if you ride in street clothes, as I do. Before I fitted it, I twice got my trousers caught between the chain and the wretched chainguard Bafang supplies. It could have been nasty but in both instances I was moving very slowly and managed to stop everything in a quarter turn.
 

bgt

Finding my (electric) wheels
Jun 3, 2015
11
0
74
The Netherlands
I found that by inserting spacers between the drive side of the motor/bottom bracket unit and the end the end of the BB shell on my Utopia Kranich, I got a perfect 54mm Rohloff chainline. Then I fitted Bafang's 44T chainring, for which you can get a Rolloff-compatible Chainglider, and the Hebie Chainglider. The Chainglider is essential if you ride in street clothes, as I do. Before I fitted it, I twice got my trousers caught between the chain and the wretched chainguard Bafang supplies. It could have been nasty but in both instances I was moving very slowly and managed to stop everything in a quarter turn.
If I put spacers on the motor unit the chainline gets worse. The Original Bafang chainwheel sticks out too much, is more away from the frame then the rear chainwheel. The Italian chainwheel brings the chain more inward so fits better for my rear chainwheel. On the rear chainwheel there is no place to bring it more outward.
 

chain

Pedelecer
Jul 14, 2011
56
4
If I put spacers on the motor unit the chainline gets worse. The Original Bafang chainwheel sticks out too much, is more away from the frame then the rear chainwheel. The Italian chainwheel brings the chain more inward so fits better for my rear chainwheel. On the rear chainwheel there is no place to bring it more outward.
The correct chainline on hub gearbox is a line parallel to the centreline of the bikr. It's distance from the centreline is determined by what's on the rear axle. The centre of the Rohloff 15, 16, & 17 tooth sprockets is 54cm from the centreline, so you want the centreline of the chainring to be within half a millimetre of that. The centreline of the Bafang chainring is at about 50mm, so on the inside of the desired Rohloff chainline, hence the spacers.

If you can find that perfectly flat chainring drilled to fit the BBS motor, that you can bolt without an adaptor or a spacer directly to the motor, like the Bafang chainring is bolted on but without the dishing, it would be a spot-on Rohloff chainline. Unfortunately no such chainring exists yet.
 

bgt

Finding my (electric) wheels
Jun 3, 2015
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The Netherlands
Rear chainring is 46 mm from the centreline of the bike.........as is the Italian front chainring. Thats why the Bafang chainring was too far out.
PS what a big/wide wheel you must have??? 54mm is quite a lot.
 
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chain

Pedelecer
Jul 14, 2011
56
4
Rear chainring is 46 mm from the centreline of the bike.........as is the Italian front chainring. Thats why the Bafang chainring was too far out.
PS what a big/wide wheel you must have??? 54mm is quite a lot.
I don't know about that 46mm. The chainline spec for the Bafang BBS is generally reported as 50 or 51mm. You may like to know that chainline is measured to the middle of the thickness of the ring.

54mm is the standard chainline for the Rohloff Speed 14 hub gearbox. It's fixed by the sprocket position.

The OLD (over locknut distance) of the Rohloff is 135mm. It doesn't determine anything about wheel and tire size.

But yes, the tyres on my bike are huge, 60mm Big Apple Liteskins on 622mm rims, with a rolling diameter of 745mm. Here's a photo essay of my bike, a Utopia Kranich, on the day it was delivered:
http://coolmainpress.com/AndreJute'sUtopiaKranich.pdf
 

chain

Pedelecer
Jul 14, 2011
56
4
No. The centreline measured to the centre of the sprocket is the chainline you want, 46mm. The chainline you have is measured from the centreline of the bike to the centreline of the chainring. With the Bafang BBS you should measure 50mm. It is most desirable, and for some hub gearboxes essential, to have a straight chainline, meaning front and rear measurements the same.
 

robwalley

Pedelecer
Apr 17, 2012
175
30
Gloucester
Currently finishing a KTM Rohloff / BBS02 36v 500w build. More by luck than judgement, this model is bang on 54mm with the standard dished 46t sprocket on a 68mm BB which matches the Rohloff 16t chainline exactly. I have ordered a 52mm sprocket from HK which gives a final ratio of 0.91 to 4.77 and the level 3 throttle I measured at 125rpm giving a top wack of 61kph (no load on the stand), interesting if the high torque on this model will get anywhere this theoretical speed.

This BBS02 kit's chainline is rather high for Alfine's and derraileurs though. I have a couple of Alfine 11 and 8's - they are about 43 and 48 respectively. I have converted a Haibike to a Alfine 11, the chainline on this is 45 and OK. I've been informed 5 or 6mm is OK, but extra wear and noise.
 
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bgt

Finding my (electric) wheels
Jun 3, 2015
11
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74
The Netherlands
No. The centreline measured to the centre of the sprocket is the chainline you want, 46mm. The chainline you have is measured from the centreline of the bike to the centreline of the chainring.
Can you draw this on the picture so I can understand what you mean!!
 

robwalley

Pedelecer
Apr 17, 2012
175
30
Gloucester
The Rohloff is definitely 54mm which matches my BBS02 500w 36v with the standard 46t chainring, this is dished already and if the italian 42t chainring matches you nexus at 46mm, then it must come in another 8mm which must be very close to the chainstay. Can't tell from the pics.