New Bafang Crank-Drives

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Tom L   1 kW

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Re: New Bafang Crank-drives

Post by Tom L » Jan 19 2014 1:57am

I was in 5th most of the way for the first half, then dropped back to 4th, 3rd and even 2nd for some of the steeper bits higher up. I was spinning about 80 RPM which I find comfortable. Yep this is the 750W kit from LC.

Edit: Regarding efficiency. I just calculated that it takes a theoretical 265Wh to raise my and my bike's combined weight that height (potential energy equation). I really dont think I was outputting more than 100W continuously, so for 27 minutes that's an extra 45Wh for a total of 295Wh used. Which works out at about 90% efficient. This drops to 80% if I was outputting 150W. Obviously with no way to measure my output this is only a very rough guess.

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Geebee   1 kW

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Re: New Bafang Crank-drives

Post by Geebee » Jan 19 2014 2:30am

That sounds promising for the 250w version then, the peak current should be similar to what you were drawing and I don't mind shifting down.
Thats a very good speed for riding up the mountain, I used to do it on a non assisted trike and bike and never averaged close to that, mind you the trike would hit triple digits on the way down :)

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full-throttle   10 MW

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Re: New Bafang Crank-drives

Post by full-throttle » Jan 19 2014 2:35am

Tom L wrote:I made it up the mountain no fuss. Started at about 450m and rode to 1271m over a distance of 11km. Trip time was 27 minutes.
Just so you know: the record (starting from 96m) is 59mins

So 27mins is impressive!

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Tom L   1 kW

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Re: New Bafang Crank-drives

Post by Tom L » Jan 19 2014 2:58am

Well I did have a bit of a power advantage.

Edit: Using the power calculation on that page and subtracting my motor's use, I was outputting 107W for the duration of the ride. This gives an overall efficiency (me and bike) of 87%.

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Re: New Bafang Crank-drives

Post by CdnE90 » Jan 20 2014 10:56am

Hi all,

I'm new to the ebike world, but after researching for a while now on ES, I think I'm going to go with the BBS02.

teslanv described almost exactly what I'm going to do in his thread here: http://endless-sphere.com/forums/viewto ... =6&t=56512. I'll start my own build thread once I start ordering the parts.

Question I have is: Can you put more than 48v to the motor? I'm thinking of going with a 16s lipo pack (4x 4s) for a nominal 60v.

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Re: New Bafang Crank-drives

Post by dbaker » Jan 20 2014 11:02am

There are 63 volt capacitors in the motor controller. 16s hot off the charger would be 4.2 x 16 = 67.2 volts. Controller goes poof :oops:

If you use 15s and limit max charge to 4.15 volts to increase battery life it would be 62.3 hot off the charger :mrgreen:

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spinningmagnets   100 GW

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Re: New Bafang Crank-drives

Post by spinningmagnets » Jan 20 2014 11:30am

Can you put more than 48v to the motor?
This drive has been run with an external controller by mwkeefer as an experiment, so I'm sure it's possible. Just be aware that you will be a pioneer at doing this, so as you begin raising the amount of power you apply, sooner or later, something will break. When that happens, please post it here so we will all learn what the next weakest part is.

When you go to a higher voltage, the motor will spin faster, so you can perhaps use a smaller chainring, or use larger sprockets at the rear wheel (or a little of both?) The classic method of getting more power is to up the volts and gear-down the rest of the drive to keep the same top-speed. The motor might not run much hotter if you limit the amps (Via a Cycle Analyst?). With no heat running through the stock controller, (which is inside the same housing as the motor), then I think the motor could take a few more amps than the stock set-up.

Either way, sounds like a fun experiment...
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teslanv   100 MW

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Re: New Bafang Crank-drives

Post by teslanv » Jan 20 2014 12:13pm

Dogman is a proponent of 14S - Which should work on the BBS02. - Your max Watts would be nearly twice the rated wattage of the motor/controller.

With my 12S, I have not wanted for power. As it is, I can still get the full 25A of current for a total of up to 1260W, when the 12S is hot off the charger (50.4V).

With the use of your rear gears, I don't see much need for 16S, unless you order it with the unlimited speed option and want to ride it up to 40 MPH. - I can easily get to my Max speed of 31 MPH with 12S. - And I just doubled the Capacity to 10AH for the better range. Also by riding at higher speeds, you will lose a lot of efficiency.

If you go with 12S have the supplier set the LVC to around 43-44V, or 3.6V/cell - (or 50.4V with a 14S pack) With 20C Lipo's you shouldn't see much voltage sag.
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CdnE90   10 mW

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Re: New Bafang Crank-drives

Post by CdnE90 » Jan 20 2014 1:49pm

teslanv wrote:And I just doubled the Capacity to 10AH for the better range.
Just curious, what is your range now?

I'm leaning towards either Conhis or BMS as my supplier for the BBS. Not sure if either of them can adjust top speed or LVC values...

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Re: New Bafang Crank-drives

Post by teslanv » Jan 20 2014 3:03pm

CdnE90 wrote:Just curious, what is your range now?
With my 12S 10AH Pack (6 each 4S-5AH Packs) The Pack is 444 WH's total.

I can get the following ranges:

PAS set to level 3 of 9: Approx. 32 miles, average of 19 MPH on the flat
PAS set to level 4 of 9: Approx. 20 Miles, average of 24 MPH on the flat
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CdnE90   10 mW

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Re: New Bafang Crank-drives

Post by CdnE90 » Jan 20 2014 5:22pm

That range sounds perfect. I've got about a 20 mile round-trip commute, so I can either take it easy on days I'm a little lazy, or sometimes take it down a notch on days I need to burn off some stress.

Where did you get your BBS02?

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Re: New Bafang Crank-drives

Post by eride » Jan 20 2014 5:56pm

I finally got my 5-hole 130 BCD chainring spiders for the BBS01/02. I got 10 pcs in 3mm alu (and one in 6mm)
I got 70T / 75T and 80T to test on the Sunrider2 velomobile
If any interest I can sell these 3mm 5-holes 130 BCD chainring spiders for BBS01/02 , price : 25€ + shipping
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teslanv   100 MW

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Re: New Bafang Crank-drives

Post by teslanv » Jan 20 2014 7:49pm

CdnE90 wrote:That range sounds perfect. I've got about a 20 mile round-trip commute, so I can either take it easy on days I'm a little lazy, or sometimes take it down a notch on days I need to burn off some stress.

Where did you get your BBS02?
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Re: New Bafang Crank-drives

Post by spinningmagnets » Jan 20 2014 8:06pm

Dank u voor het maken van deze te koop, eride! (Thank you for making these for sale, eride!)
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Kepler   1 GW

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Re: New Bafang Crank-drives

Post by Kepler » Jan 21 2014 4:05am

Had a day off today and managed to get the new bike running complete with button throttle and gearshift cutout. The gear shift cutout works perfectly and now allows me to shift any time I want without putting any stress on the gear system no matter what power setting is selected. Button throttle also works as predicted with the simple voltage divider circuit I posted up a few days ago.

I needed to add a some extra tension to the shifter using an O ring to ensure the cutout hall switch was always fully depressed when not shifting.
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Most of my bikes use a handlebar mounted battery bag. I have tried to improve on this theme on this build by attaching the bag on a second headstem below the main head stem. The advantage is that it gets the weight a bit lower and also clears all your control cables especially the stiff hydro brake lines.
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Light was not the best for pictures but here is a picture of the operational bike. I have a new wheel set to fit to bike but other then that, it is basically finished. We take some better pictures when the light is better.
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Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

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Re: New Bafang Crank-drives

Post by Kepler » Jan 21 2014 4:11am

A bit of extra action in the Kepler cave with 2 new frames awaiting mid drives. I think these two frames are the last in existence. real shame as they are IMO perfect mid drive ebike frames.
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Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

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Re: New Bafang Crank-drives

Post by deepfraught » Jan 21 2014 6:58am

Kepler wrote:A bit of extra action in the Kepler cave with 2 new frames awaiting mid drives. I think these two frames are the last in existence. real shame as they are IMO perfect mid drive ebike frames.
I was about to ask what the frame was, before I got the Thudbuster LT I was considering compact rear suspension like that with bottle mount on downtube to allow the triangle battery pack or bottle battery.

Since a new love for belt drive geared hub, my new frame hunt is for the banana swingarm without lower chainstay so no frame split for belt required.

I am a breath away from ordering one of these motors as per your info, down the slippery slope of another kit leading to another frame etc.
History: Front hub SS 200W, China E-mtb 200W, 3x A2B Metros, Commuter Booster beta, 2.4kW d/s w/DD kit, MAC 1.5kW road/flatbar 1250Wh EM3EV frame batt, BBS02 750W d/s MTB 1250Wh frame batt. All sold (except A2B Metros pending TLC from storage).

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Re: New Bafang Crank-drives

Post by Rusty123 » Jan 21 2014 11:43am

Nice work Kepler!

Could you please provide more detail about the thumb-button throttle? For example, what part(s) did you use, and how did you connect it to the Bafang wiring harness? And did it eliminate the "dead band" on the stock throttle (I wasn't sure if the dead band was a function of the throttle or the controller).

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Re: New Bafang Crank-drives

Post by footloose » Jan 21 2014 1:03pm

Rusty123 wrote:
deepfraught wrote:Does the installation use the bottom bracket threads, or does it thread one side of itself into the other, floating in the BB and clamping itself to the faces?
The latter is basically the case -- the axle assemble is inserted into the BB shell, with a threaded retaining ring (and a locking ring, depending on BB width) compressing the unit against the BB faces. The internal threads on the BB shell do not come into play.

Incidentally, in some other threads, people were worrying that this would damage the BB shell internal threads, such that a normal BB couldn't be re-installed. I don't think this would be the case, because the threads are cut into the the shell, rather the shell being cut away from the threads.
I’ve had BBS02 on a Raleigh 20 for about 300 miles of riding.
Like the kit a lot, but decided it was overkill on a bike with 20” wheels, and I would move it to a bike with larger wheels.
So I dis-assembled the Raleigh 20 / BBS02 build yesterday, and rebuilt the Raleigh 20 to its original configuration… eg, reinstalled original bottom bracket, etc.

Did have one problem.

The BBS mounting plate has small ‘protrusions’ that dig into the steel of BB shell and serve to fix the motor assembly in place relative to the bike frame.

Turns out those protrusions did deform the outermost BB shell threads slightly. I fixed the problem by filing down the BB shell very slightly (~1mm) to remove the deformed section of thread. Was then able to reinstall original bottom bracket.

Maybe more concerning: there was some evidence that the torque of motor had in fact been rotating the entire assembly slightly within the BB shell. I expected to find a single, sharp, V-shaped indentation in the steel of BB shell from each of the mounting plate ‘protrusions’. In fact, I found that each of the indentations was a bit wider than expected. Instead of a perfect V shape… each indentation was shaped more like \_/ That is, each of the indentations was slightly wider than expected.

Retaining ring and locking ring were torqued down tight when originally installed, the BBS02 was not movable by hand force, and the retaining ring and locking ring showed no signs of having loosened since the original installation. My best guess is that the power of the motor was resulting in very slight rotation of the entire assembly within the BB shell over time... eg, the mounting bracket 'protrusions' weren't sufficient keep it perfectly static, and the steel of BB was deforming slightly over time. If so, that is kind of worrisome.

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Re: New Bafang Crank-drives

Post by deffx » Jan 21 2014 2:56pm

It may be worth fixing the motor to the down tube to prevent this then? Seems reasonable

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Re: New Bafang Crank-drives

Post by eride » Jan 21 2014 4:13pm

Here a few pic's so you can judge for yourself how the chainline changes a few mm out compared with original chainline with if the chainwheel is mounted 'outside' this 3mm alu-plate ø130mm BCD 5-arm spider.

If you mount the chainwheel 'inside' the spider you will need washers under the spider if you want to run the spider free from the motor but then you can, in my opinion, almost have the same chainline as with the original BBS chainwheel. I hope I make myself clear :)
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Re: New Bafang Crank-drives

Post by speedmd » Jan 21 2014 4:30pm

The BBS mounting plate has small ‘protrusions’ that dig into the steel of BB shell and serve to fix the motor assembly in place relative to the bike frame.
You mounted it backwards! Bumps go against the nuts not the bb shell. I guess you don't read chinese :lol: Seriously this should have some picture instructions to tell how to do it.

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Re: New Bafang Crank-drives

Post by Rusty123 » Jan 21 2014 4:46pm

speedmd wrote:
The BBS mounting plate has small ‘protrusions’ that dig into the steel of BB shell and serve to fix the motor assembly in place relative to the bike frame.
You mounted it backwards! Bumps go against the nuts not the bb shell. I guess you don't read chinese :lol: Seriously this should have some picture instructions to tell how to do it.
There are picture instructions here: http://www.ebike-discount.com/online/te ... 182013.pdf

According to this, Footloose had it right! (This also makes sense -- the teeth should prevent the unit from rotating in the shell. I think it's really important to torque the transmission tight against the downtube when tightening the fixing nuts, since the the motor torque will do this under power).
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Re: New Bafang Crank-drives

Post by teslanv » Jan 21 2014 4:48pm

speedmd wrote:
The BBS mounting plate has small ‘protrusions’ that dig into the steel of BB shell and serve to fix the motor assembly in place relative to the bike frame.
You mounted it backwards! Bumps go against the nuts not the bb shell. I guess you don't read chinese :lol: Seriously this should have some picture instructions to tell how to do it.
Actually, the Chinglish Manual says to "The surface with teeth of fixing plate towards inside, then fix the plate on drive unit with 2pcs M6*10."

I would interpret that as "Install the teeth towards the bottom bracket."
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Re: New Bafang Crank-drives

Post by speedmd » Jan 21 2014 4:54pm

I did read this before installing but knew better and did the opposite as I like my bike and would not care what their reason was. IMO you are fool to think this would not trash your shell. I will strap the motor up against the down tube if it moves down in use.

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