AM dual motor = bafang middrive + rear hub motor

[John Bozi]

pulled apart my "infront of the seat pack" which contained 3s batteries to pull one out and added in series to the 12s just for the mid drive.

charged both battery systems to 4v a cell to get a feeling for what I might get into.

15s1p 60v 25 amp mid drive
12s2p 48v hub 65 amps

on road

I only got the mid up to 31kmh thats just a few km more than at 12s hot off. I don't quite understand... expecting more but I guess they is more of 14s hot off the charge voltage.

Anyway it might be that I haven't lubed the drive train but once the motor winds out at topspeed in the fasted fear grinding phase kicks and then gets passed. Before I think I just fell under that phase. Maybe there's some weird timing of when the links are bending and just vibrating in their bend poorly in some weird frequency. weird.

At first I wasn't impressed. The delay for throttle off felt much worse, a poor gear change worse than before too and the torque needed getting used to...

a bit of sunlight left I need to test the granny gear off road straight up the mountain 30% slope...

57v mid

shifter cable played up gear wouldn't stay in granny, so I had to pull the twist shift hard to hold it in that gear but it fell off the granny under load and you guessed it!

BROKE THE CHAIN

it was on the steepest section too. Anyway stuck it in my pocket and could have taken the straight route home but said nope I got a hub and enjoyed a longer route home.

First experience of riding without a chain in my life. Takes getting used to because we balance the bike with the tension we put on the pedals. Also, gave me a good experience of how it felt to ride a motorbike, with only the throttle doing all the power stuff. I like it and felt kind of like throwing the bike around more.

So the questions now are:

- if the chain had been lubed
- if I had been at lower voltage
- if the shifting cable had been tightened

would this have happened? and what combination of these?

Should I just stay away from the higher voltage....

Anyway took the broken link out temporarily and will try the same section again today. Have ordered for $66 au of ebay

Wippermann 7E8

Based around the 7R8 which is renowned for its durability and strength. The 7E8 is the perfect upgrade for any narrow hub gear E-bike. Also works with 7,6 and 5 speed derailleur systems.

Reinforced design and high-grade coating for maximum wear resistance.
Ideal for high-torque E-bikes, heavy touring bikes and fixies.
1/2" x 3/32", pin length: 8.8mm
Weight 430g/110 links
112 links incl spring clip

no idea how the link works, if my chain tool will work with it.

 

[drew12345]

Good find John. I remember reading about this. Hopefully being more durable will last longer than standard bike chain.

 

[John Bozi]

just found this elevation tool

did a rough mapping of my main ride.

 

[John Bozi]

Started off on my ride and used bafang as usual to get started up my drive way up around the first road where I then engage the hub when can go faster.

But at first the throttle didn't work. Turned off and on and well it felt jerky, but I thought it is hot off charge and Im not used to the torque, but as I rode more I knew there was something wrong with the power slightly cutting out especially on WOT for longer periods and when turned softly.

I was keen to go up to continue recording my project of the downhill run
Part 1 of the project recorded a while ago.
[youtube]ydtLWH-eqBc[/youtube]

..... and thought well I have two motors if something goes bad I can always get home.

So I set up my camera on a tree at "rob's knob" a part which only he can ever climb as there is no run up and it is steep and its rough and loose.
this is video was recorded a long time ago when Rob was the first person to do it. It gives a different perspective of the ride.
[youtube]XoEgrzIsZqM[/youtube] he took a very different line to me.


edit.

the green hall is not switching according to http://www.ebikes.ca/documents/HallSensorTestingFinal.pdf


I rode down it and then turned around to ride back up to the camera but the bike flipped again on me and I couldn't get a foot hold and slid down and the bike did on its side and like last time my hand got jammed on the throttle WOT while the wheel was pretty stuck to not being able to turn out of place. I recall a branch between the spokes and swing arm, stopped the motor from spinning. If I had put more power through it may have broken spokes. It was freaky time and my adrenalin was rushing and I was worried I may have damaged something.

I parked the bike and went back up got the camera and set up at the base and felt nervous looking up what to me feels like trying to ride up a cliff. I thought why would anyone put themselves though something that makes them feel nervous. I imagined being stuck up there with a broken arm or something worse, unconscious or something like that.

Something in me said give it another try. I went around and discovered granny gear wouldnt hold again and thought of giving up again but decided that granny is too slow to help the hub anyway so just said do it in the next gear. You've got a full face helmet and gloves and just do it.

No fucken shit, I got on the bike but this time lent so far forward my balls were almost on the steering tube lent right up there and ripped up what I am guessing is roughly 80% for about 20 metres. the granny gear would have not helped properly so it was good it didnt work. the hub would pull faster half of the time and then bog but the bafang would be ready to burst in those sections enough to give the hub a chance to go again. I was surprised the hub was 65 degrees celcius and bafang just a bit warm.

When I got the top I was yelling and yahooing like I have never done before in my ebiking days. Well maybe a few times...

So bloody happy..................

New Video recorded today unfortunately was recorded from far away when I flipped the bike and jammed the throttle.
[youtube]bebr-eU4ntg[/youtube]

After doing that I felt so high I couldnt be bothered recording anymore and just decided to ride the rest of the ride straight home.

The shifting was constantly poor - the chain constantly noisy not in gear properly, so much that I started pumping the hub more and more. until I broke the chain again.

Now I decided its mostly downhill to the suburbia and when I got to the base I hub started growlling I looked down through my vents and the halls are rubbing against the side covers.

growl

I got two fucken motors and pedals ... last time I went for a ride I put the chain tool in my pocket, forgot this time. I must remember from now on...

WALK HOME IN SHAME AFTER RIDING THE BEST I EVER HAVE

now to remember before I forget when pulling this apart.

1 washer on the outside of the dropouts on the drive side, 1 washer between dropout and rotor. all others are in the freewheel.

 

[drew12345]

Did I see another thread your selling this bike?

 

[John Bozi]

Did I see another thread your selling this bike?

everytime I have another fail I want to sell up.... just get so tired of breaking down. yes, but I doubt anyone would buy


I have pulled off the hub, controller, throttle etc

the bafang remains with 12s2p - have put the almost totally unused original rear wheel. However the 7 speed shifter wont work well with the 10 speed back and I I dont ordered that 7 speed chain....

anyway I want to ride it just bafang for a while, while I bring up the nerve to fix the hub.... I was tempted before the hall fail to go single speed with the bafang because that gear worked so well on the last climb, but now with a broken heart not sure to go all out and buy that rear sprocket and single speed tensioner or give up on running a hub.

the drag was really bad too wonder how often bearings need changing when the bike is so heavy.

 

[John Bozi]

Did I see another thread your selling this bike?

everytime I have another fail I want to sell up.... just get so tired of breaking down. yes, but I doubt anyone would buy


I have pulled off the hub, controller, throttle etc

the bafang remains with 12s2p - have put the almost totally unused original rear wheel. However the 7 speed shifter wont work well with the 10 speed back and I already ordered that 7 speed chain....

anyway I want to ride it just bafang for a while, while I bring up the nerve to fix the hub.... I was tempted before the hall fail to go single speed with the bafang because that gear worked so well on the last climb, but now with a broken heart not sure to go all out and buy that rear sprocket and single speed tensioner or give up on running a hub.

the drag was really bad too, wonder how often bearings need changing when the bike is so heavy.

EDIT
Went for a short spin around the jumps OMG this feels like a bicycle again!

 

[drew12345]

Yeah, I hate it when stuff breaks! it's fun when it's working but when broken, have to spend time fixing it instead of riding.

Hey, at one point you had these neoprene wraps around your batteries. Where did you get those from?

 

[John Bozi]

I went to a rubber shop in Australia its called clarks rubber.

I use hard neoprene sheets where they sit on the frame. The soft sponge tube that I bought was like a insulator and the batteries were hot as hell in there. I know it is dangerous but my batteries breathe from the sides now and they are always cool compared to before.

My main concern has always been branches. hardwood stuff has always kicked up and hit under the down tube or jammed inaround the bb or rear wheel. That and mud is why I delayed so long on building the under the downtube battery box. with so much more aluminium to protect them the bike would have been even heavier.

I need to look into getting a clean 10 speed shifter back on the bike for the rear cassette now.

I' love the no drag of the bafang. I wonder if I can find another small motor for the brake rotor...

 

[John Bozi]

yesterday went out for some single tracking pissed down rain on me out there lucky I had plastic bags to cover my lipo and throttle/display got drenched to home, but bats were dry...

was what I have said before hubs are better for technical stuff because of their power band. However the bafang is cool because it forces me to exercise.

today i went to use a cell checker and pulled out some balance plugs (that I had repaired a long time ago after shorting them) and the yank on them pulled all the shrink tube down and I had a sweet surprise of shorting plugs flame and crack.

so scary trying to grab them one by one away from each other without burning my fingers. Just e taped them carefully, untill they were clear and then shifted the shrink tube up again and re e taped them and taped them all together again... freaky

my 3p plugs arrived but don't see a use for them now. Im sure Ill find a use for them at some time.

realigned the rear cluster so that 11t would work since granny never wants to work with the 7s shifter. was cool to run around on the 26" wheel 11t top speed is around 38kmh vs before at 28.

I have to pedal like crazy in the wrong gear to get up on road hills around my suburb - but thats cool because i need exercise.

complex thoughts as usual. this is the time to order parts to get the whole set up going and have the bafang going till then. yet i dont know if I want to go back to the hub for now.

If go to the hub I could just order a sensorless controler or a dual one and if I were to run the hub with the mid I know i want the white industries single speed freewheel.


otherwise if I decided to stay just with bafang I should get either a 10 speed click shifter to make clean shifts or because i already ordered the 7speed chain get a 7 speed rear cluster....

so many thoughts again...

I think there's no rush and I should just run the bafang poorly for a while longer (always carrying my chain breaker in my pocket).....

Its fun but pretty low in torque when I need it but exercise!!!!!!!!!!!!

 

[pendragon8000]

Blanance lead shorting is some serious shit.
I'm looking into arduino BMS but its about $100 for 20s

There is a company doing good BMS but not retail

 

[drew12345]

I've shorted some balance plugs before. It's not fun at all. Every time I touch my lipos, in back of my mind I think they are going to explode. So when I see a little spark, it scares the crap out of me.

Anyway, get the dual sensor controller. I know you love the speed so get the hub working again :wink:

I just replaced my other bike (the one with hub) with new frame and 24 inch wheels. Smaller wheels makes a huge difference! I might go even smaller later. I have to see how it handles on the trail for me because I want to use for both street and offroad.

 

[John Bozi]

drew I think I will follow your advice.

I wanted to give the bafang a go, but I have never ending chain break problems. I know I could improve this by spending more money on clean shifting set up but why bother when it seems a bit too underpowered most the times.

Today, I went down the jumps because I couldn't go up the mountain because the granny isn't working properly and it's crucial in 26" wheel.

Basically there is not enough torque even on the jumps to get the height I was getting on my heavy bike set up....

[youtube]4yMsQBDJvGQ[/youtube]

started recording but too many kids turned up. I had to do long run ups to get speed enough...

 

[drew12345]

You still got some good air! I'm terrible at jumping.

I hate it when you are about to record something and bunch of people get in way and have to stop recording.

 

[John Bozi]

Drew you jump fine. Go up stairs better

So much dam rain. My city is getting dumped on by the end of a cyclone. Hardly ever get a chance to ride...

When I broke my chain the 4th time or second last time I said to myself if I ever use dual motor the mid drive has to go to single speed so it is always perfectly in gear.

I however said after conquering "rob's knob" I don't need granny as it is too slow to help the hub. which is true. but if I want to climb very long very steep stuff (quite rare but only because it gets avoided) then the 32t granny was still not enough.

So have ummed and ahhhhred for a long time to give up on the hub and just use bafang or get the

white industries 23t = maximum teeth which would work well with an ordinary derailleur or
get

Products Total
1 x HD Freewheel Removal Tool for HD freewheel $11.95
1 x Front Freewheel - Heavy Duty $79.95
1 x Chainring Hardware $4.49

As I just bought. Not cheap with the Aussie dollar at .75

The ultimate reason I went with the front freewheel is I hope if everything works out right. I can change my sprocket sizes. I can run I think anything from 24-52t quite easily and with offset teeth sprockets be able to dish stuff outwards a little.

Not too sure where to start but think I will order a 44t bafang front chainring and see if they fits at the back. I like the look of them because they are black and not solid metal.

I will probably still hook up my 10 speed shifter on the bike with the bafang for another month or more to just enjoy light riding (might fall in love) but have a feeling I might need my mountain goat back.....

This the new controller I plan to buy for the hub:
http://www.aliexpress.com/item/24FET-IRFB4110-s-3000W-48-84V-80Amax-BLDC-motor-controller-EV-brushless-speed-controller-sensor-sensorless/522263950.html

dunno if its because of Chinese new year but can't get any contact with them about specifics
a sensorless 24fet 80amp - it should be bullet proof... big and long and will have to take up the downtube position.

 

[drew12345]

Get a big block and mount on swing arm. Run to single big sprocket in back. Is that what you are trying to do? Yeah, single speed would be great. Can still have chain drop if tension and alignment is not correct.

 

[John Bozi]

motor on the swing arm is another possible project. What I wrote above is just using the bafang still.

I have been researching but can't find my way around many things in the direct chain project.
Most motors that go on the left and cant work in reverse or not as well, so wont work with pedal drive system if they take up the chain space on the right.
Many of the big block projects use foot pegs.
high power through front chainrings is what I want to avoid (cyclone style)/lightning rods

long custom swing arm on what bike?

too many questions still.

I knind of wish I bought a headline motor instead of the bafang now, I would have been able to custom the chain line better if mounted (and if it fit) on the swing arm or on the down seat tube....

Anyway they look too wide to get the right chain line. That's why if I could custom cut off the axle on a big hub motor and if I could find a way to fit it on the swing arm this would be my first choice or big block but then I go into new motors that I dont understand.

 

[Gab]

I knind of wish I bought a headline motor instead of the bafang now, I would have been able to custom the chain line better if mounted (and if it fit) on the swing arm or on the down seat tube....

Yeah the chainline on the BBS02 is probably one of the worst things about it, it only has 1 gear and this is way too far out.


Other kits like the cyclone and AFT have 2 chainrings up front and they both have a lot better chain line than the BBs02 cause it has that big hump of a gear in the same spot as where the gears should be to get a good chainline, Fail design.

 

[John Bozi]

I agree Gab.

Temporarily my bike is looking good for a while thanks to http://www.madmanebikes.com

I did think we would just do a quick shifter change but ended up customising the cassette moving three cluster of grannies outwards and pulling apart another used cassette for parts and spacers. Problem was then my zee arm that holds the shifter cable would hit the granny so then went and trialled about 4 deraileurs until finding 7 speed one that would allow the granny to work.

so I now have a much better probably about 2 cm better granny chain line click push and pull shifter that has 4 gears working perfectly. 11t 36t and a few in the middle.

I think one of my big problems was that everytime I broke the chain it got shorter.... I have a new 10sp shimano on now and so far on road test rides it all works perfectly.

Also Zack, did one of the quickest hall sensor replacements, tightened up some wires on the old hub.

The old hub isn't looking that flash though, I spotted a darker spot on the copper.... I need new bearings as well.... I got lots of stuff to do still to get the hub back online and while I wait I now have my single track light rider to play with



EDIT:
I ordered this for my rear sprocket

48t

I will be going to a single speed for the bafang after off roading again and having another poor shift experience. The bafang alone was overheating" at the point of to hot to hold..... and their were parts I had to get off and walk....

Edit 2:

Just noticed cassette wobbles in and out a lot. does that under each shift or with a little force with a finger on granny sprocket...
anyway hopefully will hold up till hub is back on line...
did some single track but had to walk a bit because it was on fire almost up a steep mountain.... and still had a slip...

Anyway waiting till the 5th of march for the chinese doods to get of chinese new year to get a new controller.

Edit 3:

Everything has arrived apart from the sprocket that I need and still no replies from greentime about the controller I want.

Now I have a HD chain connex, HD freewheel that fits, bafang stock 44t front chainring that I might never use as it doesnt fit the hd freewheel. I have put new bearings on the hub and had issues with spacing as usual with the stator touching the halls again. I flipped everything 180* and yes the screws don't fit perfectly but have gained about 1mm clearance.

I do love my bafang only as a street commuter, but this bike needs to get back to what it was, the ultimate mountain climber. I will run sensored until I get a bloody reply from green time about their controllers.

 

[John Bozi]

Anyone who tells you running an ebike will save you money is simplifying things too much.

I have run lipo for a bit over a year and my power supply (not some elcheapo psu mod) has progressively given me less power. It finally is now only not shutting down on about 3 amps. Thats bs when I run 21s2p and 12s1p amount of cells.

I hate that I went back to the same company but just couldnt find anything out there with the same specs. I'm not into seriesing computer psus all over the place either.

$300 au delivered from australia (will keep my warranty papers safely this time)

just ordered this

http://www.ebay.com.au/itm/161550145578

I am now also scratching to get more chargers but can't decide if I get an 8s one or not.

 

[drew12345]

I have same power supply. Very nice.

 

[John Bozi]

thanks drew for the reassuring words.

My last research is how to tension the chain with 48t rear... Not too many bicycles run single speed full suspension that large... the yess systems usually are for ss fs with small sprocket

Anyway might have to start a new thread for this, as I don't seem to be able to find anything that will work off the shelf.

 

[John Bozi]

surprised I got my power supply so quickly.

But not happy that the problem is still with me....

NO idea http://endless-sphere.com/forums/viewtopic.php?f=14&t=67612#p1019302

Drew can you confirm how many amps can you get on the 10amp switch outputs? when y ou draw 10amps on the ps display how many amps are you getting on your charger display, or when you draw 10 amps on your charger how many does it say on the ps?

 

[John Bozi]

she's heavy and big!

will try something moto to get around the size

 

[John Bozi]

No need to PM, so will share here.

I run two motors on the same bike. One BBS02 mid drive and then a hub. And in the pic there is a large hub behind the big sprocket. The large size sprocket is to be able to crawl the steepest hills with the BBS02 motor. I have run a 7 speed cluster, but found I still wanted more teeth even with my 20" wheel! Of course having more gears to choose from is better, but it doesn't quite work that way. It is very very hard to get clean shifts with 7 speed twist shifter or any other shifter I tried. A few poor under load shifts a ride means the chain could snap at any time.
I did think for ages whether to get a 23t freewheel or this hd adapter... I may in the future go to the 23t but for now I can "easily" (no hub motor is really easy) just change what ever sprocket I want on the back.

I tried bafang alone in 26" wheel and it is way too underpowered to climb and overheated in notime. I could try it in 20" wheel in future without the hub. but in my opinion if you are going to have something at the bottom of your bike that is low to the ground that means there is some terrain you have to be very carefull. so for me it is not in the ideal place to dedicate a bike to.

Both motors can run the same voltage from the same battery pack, that's up to me if I want everything to run at 12s or if I want massive speed to run them seperate. I will most probably run 1 pack at 14s eventually. that's the highest the bafang can handle. The reason for having all the batteries together is for a higher amp draw possible, and higher amounts of healthy regen and easier charging in 3p. However I lose my choice of top speed. I like 60kmh as my top speed to keep cars behind me at times, can't do that on 14s.

My hub can accelerate like flip on your back. It flies from a stop. But nobody needs that. I start with bafang and then kick in the hub. Yes you save power if you aren't in a rush.

Now, I still burn blow things so I will eventually go sensorless. For that the bafang will become completely essential, since they say you need to pedal first with sensorless.
So in that way I would not choose an rc motor which I think is the same deal?

If you had a 30t granny (would work easy with bicycle derailuer), you'd use it from 0-10kmh probably depending on your wheel size.

sperate throttles are way better for me, I have no problem running a twist shift on my right and a thumb throttle on my left. It becomes and second nature as looking for the regen button before ever using your brakes. Regen is a massive advantage to this set up. I feel so much more in control descending massive steep mountains.

There are disadvantages.

weight - I added about 5 kg
wiring clutter

The only reason I would ever suggest dual motor route is if you are having over heating issues after doing all the other mods you can do.

I have vented and gone a small wheel.

The other option would be to start with a big block mid drive motor vented and see if you ever need anything else. I started from hub side.

People say: you just find the right motor (not two).

But as I mentioned I don't have much luck with gears and making them all shift perfectly. One day I want a clean big motor on the swing arm only so no reduction chains and tensioners. that's my future. So I can just pull of the wheels throw the bike in the car. with a hand full of sprockets and chains to choose from. If I am going out to some flat destination small sprocket..... etc.