New Bafang Crank-Drives

[samsavvas]

Hi folks,

I have a quick query about BBSxx installation practice. I recently installed my 2nd BBSxx - a 350w/36v - on a Surly LHT built up as a commuter/every-day transport hack. It's the first time I have had to deal with the potential interference with the under-the-BB route of the rear derailleur cable. How do people do it? I know you are supposed to have the motor casing butt up hard against the down tube to stabilise it and resolve any tendency for the drive unit to try to twist around it's BB mounting. But unfortunately on the LHT this pushes 8mm or so into the rear gear cable's route under the BB.

Do you just accept this and let the cable run against the casing? Or do you mount the motor off-set a bit, rotated down maybe 10mm and away from the down tube? It seems to hold ok in this position statically but I'm worried that under repeated torque loads it may work it's way loose. Maybe this position would be OK if I glued in a really solid plastic or rubber spacer between casing and d/tube?

What is established practice please or do the engineers on the list have a recommendation? Kepler - has this 'problem' vexed you at all?

Thanks,

Savvas.

 

[tahustvedt]

Hi folks,

I have a quick query about BBSxx installation practice. I recently installed my 2nd BBSxx - a 350w/36v - on a Surly LHT built up as a commuter/every-day transport hack. It's the first time I have had to deal with the potential interference with the under-the-BB route of the rear derailleur cable. How do people do it? I know you are supposed to have the motor casing butt up hard against the down tube to stabilise it and resolve any tendency for the drive unit to try to twist around it's BB mounting. But unfortunately on the LHT this pushes 8mm or so into the rear gear cable's route under the BB.

Do you just accept this and let the cable run against the casing? Or do you mount the motor off-set a bit, rotated down maybe 10mm and away from the down tube? It seems to hold ok in this position statically but I'm worried that under repeated torque loads it may work it's way loose. Maybe this position would be OK if I glued in a really solid plastic or rubber spacer between casing and d/tube?

What is established practice please or do the engineers on the list have a recommendation? Kepler - has this 'problem' vexed you at all?

Thanks,

Savvas.

Just put something between the downtube and motor. I used double sided tape and a piece of rubber on my Surly Cross Check.

 

[bissont]

I just wanted to say thanks for this thread and its wealth of information. I bit the bullet and bought this 500w motor and 48v 11ah battery from em3ev. Here's a pic of my new mistress.

 

[teslanv]

Looks good. I see the cycle analyst up there next to the Bafang Head unit. Is that just the CA-SA version with a shunt between the battery and drive, or did you do the throttle integration mod as well?

 

[idar]

I am looking for a battery for BBS01. Evernyone seems to sell this http://em3ev.com/store/index.php?route=product/product&path=35&product_id=160 battery.

I am planning on mounting this on a trike (Ice Sprint26). And would like to have a rackmounted battery. Anyone know of a shop that sells good rack mounted batteries.
Greenbikekit, has one 15ah but they said it was lipo and its a bit heavy 5kg. I would like some newer cells maby samsung 29E cells.

Mounting the battery on the rack i need around 2m battery cable to the motor. Is that a problem?
Would an extension cord with two plugs be a problem?

 

[arclarke]

Hi Arclarke,

I wanted the battery to be a good mix between capacity and weight. It seems that this 11.6 is exactly what I needed, I'm always keeping in mind battery conservation when riding, so I'm not hammering the throttle the whole time, and i'm also pushing quite hard on the pedals.
To give you an idea, after that big hour of riding at 40/45km/h the battery voltage is around 46.4V and everything is barely warm not to say fresh for the battery. Unfortunately I don't have any measurement device onboard for now.
I also went to a round trip in my hilly countryside and returned with a 112km trip, averaging nearly 35km/h and took me a bit more than 3h15min, the whole thing was with a 1500+ pos ascend in total, no stops. The battery was 44.2V at the end.
So it definitely depends on how hard you are on the throttle and how much you assist the motor. Err, wait a minute! Isn't the motor supposed to assist you?.. :lol:

Thanks for the feedback, sounds good. I guess you're putting a fair amount of power through the pedals, and riding in quite an aerodynamic position.
Alan

 

[tahustvedt]

I thought my Bafang has failed the other day. I was riding and suddenly it started making a terrible noise, and dragged a lot. I stoppped and checked it out and then I saw that it had pulled the rear wheel out of the horizontal dropouts. I had just installed lightweight quick releases which don't hold as well as the old.

Today I heard a bad noise again. This time the wqheel was in place. I couldn't find anything so I rode on, but the sound was still there. I stopped and looked around the wheel and drive train. There was a leaf stuck between the fender and the right rear cantilever brake. Phew.

The Bafang took me shopping today. So much more fun that driving.

 

[dbaker]

Beautiful scene

 

[Digital_Rider]

Hi guys,

I'm extremely interested in building up a drop bar commuter bike based on the Bafang BBS02 drive. I've been looking at the Trek Crossrip as it seems to be a perfect host for what I'm wanting to do. Long chainstays, 68mm BB shell, disc brakes with 135mm rear hub, full sets of rack and fender mount points front and rear, etc.

I'm concerned about the downtube / bottom bracket junction though, as it is kind of unique. Could some of the Bafang mid-drive experts in this thread take a look at the following pictures and let me know how well the BBS02 would fit on this bike? I'm worried that the cable exit area on the downtube comes straight out from the BB a bit and might not allow good rotation forward for the motor unit, but I also don't know if there might be something I am missing that wouldn't allow it the unit to fit at all!

Thanks for your help, and I love all of the cool builds!!







View attachment 1

 

[Warren]

tahustvedt,

"then I saw that it had pulled the rear wheel out of the horizontal dropouts. I had just installed lightweight quick releases which don't hold as well as the old."

Yes. This is what you want,

http://bicycletutor.com/images/bike/quick-release-skewer.jpg

or this if you are concerned about weight.

http://static.jensonusa.com/images/Default-Image/Zoom/852/HU249Z07.jpg

Any of the ones where the lever acts as the cam, running on a concave plastic piece are crap, as the cam sinks into the soft plastic!

http://static.jensonusa.com/images/Default-Image/Zoom/606/QR285A00.jpg

 

[Digital_Rider]

tahustvedt,

"then I saw that it had pulled the rear wheel out of the horizontal dropouts. I had just installed lightweight quick releases which don't hold as well as the old."

Yes. This is what you want,

http://bicycletutor.com/images/bike/quick-release-skewer.jpg

or this if you are concerned about weight.

http://static.jensonusa.com/images/Default-Image/Zoom/852/HU249Z07.jpg

Any of the ones where the lever acts as the cam, running on a concave plastic piece are crap, as the cam sinks into the soft plastic!

http://static.jensonusa.com/images/Default-Image/Zoom/606/QR285A00.jpg

Yep, internal cam skewers are what you want for sure!

http://www.universalcycles.com/shopping/product_details.php?id=16379
^^ Mountain 135mm rear dropouts

http://www.universalcycles.com/shopping/product_details.php?id=7251
^^ Road 130mm rear dropouts

 

[Kepler]

Hi guys,

I'm extremely interested in building up a drop bar commuter bike based on the Bafang BBS02 drive. I've been looking at the Trek Crossrip as it seems to be a perfect host for what I'm wanting to do. Long chainstays, 68mm BB shell, disc brakes with 135mm rear hub, full sets of rack and fender mount points front and rear, etc.

I'm concerned about the downtube / bottom bracket junction though, as it is kind of unique. Could some of the Bafang mid-drive experts in this thread take a look at the following pictures and let me know how well the BBS02 would fit on this bike? I'm worried that the cable exit area on the downtube comes straight out from the BB a bit and might not allow good rotation forward for the motor unit, but I also don't know if there might be something I am missing that wouldn't allow it the unit to fit at all!

Thanks for your help, and I love all of the cool builds!!

The drive looks like it will fit OK. You might need to take a little bit of material off those cable guides to get it clear though. Also check if the BB uses press fit cage or screw in type.

I love Trek bikes and this will make a superb commuter.

I took delivery of Trek Domane 5.9 a few days ago for use as my main fitness bike.

 

[samsavvas]

I'm concerned about the downtube / bottom bracket junction though, as it is kind of unique. Could some of the Bafang - in this thread take a look at the following pictures and let me know how well the BBS02 would fit on this bike? I'm worried that the cable exit area on the downtube comes straight out from the BB a bit and might not allow good rotation forward for the motor unit, but I also don't know if there might be something I am missing that wouldn't allow it the unit to fit at all]

I haven't measured it exactly myself but I understand from previous posts that the BBSxx requires 12mm clearance around the outside of the BB shell. When installed the motor is supposed to be mounted so that it is rotated up to press firmly against the down tube. If you trace a profile of the side outline of the shell and end of the down tube and then draw a circle 80mm radius from the centre of the shell outline you should start to get some idea of how it will mount. Your main issue seems likely to be a lower positioned motor unit than it would be on a bike with a smaller diam d/t. This may not really be an issue - I doubt it will be lower than your chain ring and on a CX bike you'll probably have a higher BB anyway. I think somewhere on this thread in a previous post someone has actually posted a side-elevation diagram of the BBSxx that might be useful.
Savvas

 

[tomjasz]

I am looking for a battery for BBS01. Evernyone seems to sell this http://em3ev.com/store/index.php?route=product/product&path=35&product_id=160 battery.

I am planning on mounting this on a trike (Ice Sprint26). And would like to have a rackmounted battery. Anyone know of a shop that sells good rack mounted batteries.
Greenbikekit, has one 15ah but they said it was lipo and its a bit heavy 5kg. I would like some newer cells maby samsung 29E cells.

Mounting the battery on the rack i need around 2m battery cable to the motor. Is that a problem?
Would an extension cord with two plugs be a problem?

Everyone sells the CASE, not all batteries are created equal. Check the length of the battery from EM3ev and your rack. I have two and they would fit very nicely on my bikes rack rather than the down tube, and look very nice at that. I would stick with EM3ev. I've tried ordering from other, both foreign and domestic. Paul AKA cell_man at EM3ev cannot be beat for value, service, and price. Period.

 

[idar]

I am looking for a battery for BBS01. Evernyone seems to sell this http://em3ev.com/store/index.php?route=product/product&path=35&product_id=160 battery.

I am planning on mounting this on a trike (Ice Sprint26). And would like to have a rackmounted battery. Anyone know of a shop that sells good rack mounted batteries.
Greenbikekit, has one 15ah but they said it was lipo and its a bit heavy 5kg. I would like some newer cells maby samsung 29E cells.

Mounting the battery on the rack i need around 2m battery cable to the motor. Is that a problem?
Would an extension cord with two plugs be a problem?

Everyone sells the CASE, not all batteries are created equal. Check the length of the battery from EM3ev and your rack. I have two and they would fit very nicely on my bikes rack rather than the down tube, and look very nice at that. I would stick with EM3ev. I've tried ordering from other, both foreign and domestic. Paul AKA cell_man at EM3ev cannot be beat for value, service, and price. Period.

Thanks, i will probably go for em3ev. and mount the battery on the rack. He can probably fit me with a longer cable.

 

[teslanv]

I've been running my BBS02 25A 750W drive on 12S LiPo since I bought it. (50.4V Max.)

I Just ran it on 60V. (16S configuration, ran down to 3.83V/cell.)

Wow, that made a lot of difference!

I may have to get a couple 2S or 3S packs to add in Series with my 12S. That was FUN!

 

[ScooterMan101]

Has anyone here researched, or have put the Befang BBS02 750 watt mid drive on a Bicycle like a Road/Cyclocross/Modern Mountain Bike
with
The BB30 Bottom Bracket ?
or
The BB86 Bottom Bracket ?

Many lower priced bikes are spec'd with the BB30 or BB86 for the last few years.

 

[tahustvedt]

Has anyone here researched, or have put the Befang BBS02 750 watt mid drive on a Bicycle like a Road/Cyclocross/Modern Mountain Bike
with
The BB30 Bottom Bracket ?
or
The BB86 Bottom Bracket ?

Many lower priced bikes are spec'd with the BB30 or BB86 for the last few years.

BB86 can't be done without milling down the sides of the bottom bracket as the bottom bracket is way too wide. BB30 would require adapters, but would probably be pretty easy to do if the bottom bracket wall isn't too thick for the Bafang to fit.The space between the Bafang shaft tube and motor housing is approximately 12 mm, maybe a little more.

 

[ScooterMan101]

Does that mean the center of the crank ( same as the center of what would be the center of the Bottom Bracket Shaft ) to the outside of the Frame where the Bottom Bracket is housed, has a maximum distance of 12mm ?
If that is so then,
Not even my Cro-Molly 68 English BB , shell on my old Mountain Bike would not even work ! nor any BB Area

Did you mean a different number than 12mm ?

Takk

 

[tahustvedt]

No, the shaft housing is 33,5 mm, and the space between the shaft housing and the motor is ~12 mm. Some frames have very thick material around the bottom bracket and won't let the Bafang unit slide in without the motor housing hitting the frame. I actually found a drawing of the Bafang which shows the dimension I'm talking about. The Bafangs we use in this thread are not 100% equal to the one in this drawing, but the 12.8 mm dimension is the one I'm talking about.

 

[ScooterMan101]

No, the shaft housing is 33,5 mm, and the space between the shaft housing and the motor is ~12 mm. Some frames have very thick material around the bottom bracket and won't let the Bafang unit slide in without the motor housing hitting the frame. I actually found a drawing of the Bafang which shows the dimension I'm talking about. The Bafangs we use in this thread are not 100% equal to the one in this drawing, but the 12.8 mm dimension is the one I'm talking about.

By the picture, I can see that if the inner ( ID ) of the BB is 33.5 mm ( Mine is ) and the body of the Befang BBS02 needs to clear the bottom bracket area , then the measurement to the outside of the Bottom Bracket Area ( Aluminum/Steel/Ti/Carbon Fiber should be no more than 28 to 29 mm .

So for me , and anyone else following this thread, a good way see if the bicycle you want to use this BBS02 drive on, will work, is to measure the middle of the BB Spindle ( Half of 33.5 mm = 16.75 mm then add 12 to 12.7 mm which equals 28.75mm to 29.55 mm.

So , I would go with 28mm to 29mm to be on the safe side. any Carbon bike or Suspension Bike with more than that would, not work.
Takk tanustveat

Now off the bike store in a couple of days .

 

[Kepler]

That is a fair method of checking to see if the drive will fit. However, there is one more consideration to take into account and can be a trap for young players.

Make sure the crank side face of the BB will fit into the recessed face on the drive. If you carried the 29mm radius radius rule of thumb all the way across, The BB will not sit on this face and subsequently push out your chain line by up to 5mm.

Maximum radius at the crank side BB face is 24mm.

The following picture might help better articulate what i am trying to say The first picture has a 12mm rod in the BB clearance gap.

 

[Fishy1]

Installled a new 48 volt 500 watt BBS02 model on my daughters bike. Kit is from EM3EV including frame battery. Initial turn on of the battery got a dead display, no response from throttle. Brought the bike back home and bought a multimeter. Confirm battery is fully charged. Tomorrow I will double check the battery frame mount to ensure battery continuity. I have disconnect all connections leaving only display and throttle connected but still no luck. I have pulled all connections apart to ensure no bent pins etc. :?

I have emailed Paul at EM3EV for advice but it is too early to expect a reply. Any thoughts from the forum?

 

[Kepler]

Silly question, but did you push and hold the display on button for a few seconds? Battery Polarity correct?

 

[Aushiker]

I am looking for a battery for BBS01. Evernyone seems to sell this http://em3ev.com/store/index.php?route=product/product&path=35&product_id=160 battery.

I have the actual EM3EV battery and can support Tom's comments on dealing with Paul.

I am planning on mounting this on a trike (Ice Sprint26). And would like to have a rackmounted battery.

I have racked mounted this battery on my Bacchetta Giro 20 ATT. You can see it mounted in the photo below which was an early attempt using a Topeak rack which turned out to be to tall as you can see. I have now replaced the rack with a much lower profile one I had (sorry no photos as yet) and the fit is pretty much spot on.

The slider can be easily bolted to the rack without interfering with the battery.

If you are ordering from Paul, I would with hindsight talk to him about making up a suitable length lead from the motor back to the battery. If doing this I would have the connection at the battery end to make removal of the battery easy. In my case I didn't so I simply cut off the connectors that came with the battery and motor and replaced them with Anderson Power Pole connectors (45 amp) and made up my own made-up power wire to the motor using 12 AWG wire.

I am still fine tuning my setup but have started writing the conversion here [very much work in progress]. Still need to get a whole new set of decent photos but it should give you some ideas from the perspective of a recumbent build.

Would an extension cord with two plugs be a problem?

No (see my comment above) but good luck on getting the Bafang connectors ... Paul didn't have them when I asked him about them.

Regards
Andrew