Bafang Ultra Fatbike build

[weetard]

Some Ultra motors have the white connectors for PAS/Torque.
How to determine which wire is which?




+5V and GND is easy.
You can see it on the backside of the controller board.



I still have a picture of my plug that will make it easier.


orange | purple | white
black | brown | green

These colors correspond with :

+5V | Pasphase | PAS
Gnd | Torque | Speed/Dir



You can check with a multimeter

Between Gnd and PAS : gives you a pulse signal when rotating the crank FWD and REV 0V | 5V | 0V | 5V etc...

Between Gnd and PASphase : gives you a pulse signal when rotating the crank FWD and REV 0V | 5V | 0V | 5V etc...

Between Gnd and Speed/Dir : gives you a pulse signal (0V or 5V) when rotating the crank FWD and 5V constant when pedaling backwards

Between Gnd and Torque : gives around 1V and a bit more when you put torque on the pedals.

yup, too much for me! thanks for posting tho!


i got the bbshd coming this week...ill just run it with the stock settings!

[Daxxie]

Some Ultra motors have the white connectors for PAS/Torque.
How to determine which wire is which?




+5V and GND is easy.
You can see it on the backside of the controller board.



I still have a picture of my plug that will make it easier.


orange | purple | white
black | brown | green

These colors correspond with :

+5V | Pasphase | PAS
Gnd | Torque | Speed/Dir



You can check with a multimeter

Between Gnd and PAS : gives you a pulse signal when rotating the crank FWD and REV 0V | 5V | 0V | 5V etc...

Between Gnd and PASphase : gives you a pulse signal when rotating the crank FWD and REV 0V | 5V | 0V | 5V etc...

Between Gnd and Speed/Dir : gives you a pulse signal (0V or 5V) when rotating the crank FWD and 5V constant when pedaling backwards

Between Gnd and Torque : gives around 1V and a bit more when you put torque on the pedals.

[Daxxie]

How I wired it:


Phase
Phase wires go to Phase wires on Phaserunner


Hall
Hall Connector has 6 wires.
5V and Ground + 3 Hall sensors and a white cable that is a NTC thermistor that I connected to the CA to monitor the temperature.


PAS
It took some time before I figured this one out.

The Ultra's PAS needs 5V, you can steal 5V and ground from the CA or from the Phaserunner. (There is 5V and ground at the PR throttle connector.)
The CA didn't pick up the PAS signal from my Ultra. I had to add a 20K pull-down resistor between Pas signal and ground to make this work.
The Green Dir cable is not used
The Purple Pas Phaseshift is connected to the dir tab on the CA
Brown Torque goes to the Trq on the CA.

My Ultra had a Higo6 connector for the PAS with the right colours, which made it a bit easier.




This is a diagram I made:



I used the standard Bafang Speed sensor.
Gearsensor and 1X Magura MT5e rear brake.

[Daxxie]

The reason for installing a Phaserunner was:

- I had another Ultra drive at home with a broken controller. And spare parts are impossible to find.
- I wanted more power.

The plan was to remove the Controller and replace it with the Phaserunner.
But would a phaserunner fit inside an Ultra drive?

Only one way to find out.
I ordered a CA3 and a Phaserunner and took some measurements.

First I hooked it all up and did some tests.



The Ultra runs quite well with the PR.

The Phaserunner is about 1cm to big to fit inside the Bafang drive.
With a little modification (hacksaw!) it might fit.

The PR can be shortened a bit.



And the motorcasing needed some milling.

[Daxxie]

amazing build. is installing the phaserunner something a newb could do?

what are your speeds and battery life with this setup?

thanks

It wasn't so hard to install. But you have to be comfortable with cutting wires and soldering on new connectors.
I modified the Cycle analyst from JST to Higo connectors.

Mounting the Phaserunner inside the Ultra is not for the faint harted. (There is a hacksaw involved!)
Making the Ultra's torque sensor work was the hardest part.

I will put some instructions for people who would like to do the same.


About speed and battery life. I still have to build the battery for it.
I ordered 120X 30Q's to make a 72V 20S6P battery.

With the "old" battery of my other fatbike (52V 14S5P 40A max)
it reaches a top speed of 59km/h. @2200W

[weetard]

Wanted more power!!!
Installed a phaserunner in the drive.

amazing build. is installing the phaserunner something a newb could do?

what are your speeds and battery life with this setup?

thanks

[Daxxie]

[Daxxie]

Wanted more power!!!
Installed a phaserunner in the drive.

[Daxxie]

Forgot to ask - is the motor mount cast titanium - did the frame builder make that too? If so, wow, they're well equipped ...

Sure, full titanium.

[ncmired]

Forgot to ask - is the motor mount cast titanium - did the frame builder make that too? If so, wow, they're well equipped ...

[Riderofbike]

Nice bike.

[Daxxie]

Some updated pics.

[Daxxie]

fantastic!
Daxxie what happens if you were to NOT drill those holes?
Did you replace the cabling with Higos to allow for those small holes? Looks like the stock connectors are JST based on what I am seeing at Luna.

Yes they are JST's. There is only 1 electric cable with JST that goes to a drilled hole (the speed sensor)
I cut it and resoldered it.

2 Power cables go straight up to the battery. I drilled those in the motor mount. Downtube could have been possible also but that would weaken the frame too much.

The main harness goes up the downtube and comes out in the provided holes.

Only tricky part is the derailleur cable. Goes in on the top of the downtube, connects to the gear sensor hidden in the downtube, runs over the motor and exits the motor mount at the drilled hole at the back straight to the derailleur. Hope that will work without to much friction on the cable.

[Daxxie]

Nice build. How much will it have cost when it is complete?

Oohh, didn't calculate yet.

Roughly:

Frame, handle bar, seatpost, headset + shipping 1200usd
Bafang Ultra Ludicrous + Thumb Throttle and some other stuff + shipping 1200usd
Secondhand wheelset 300€
Magura brakes 160€
Other small stuff 200€
Bluto fork I took from my other bike
Battery: I will use the shark of my other bike for now.

[MoneyPit]

fantastic!
Daxxie what happens if you were to NOT drill those holes? I'm looking at the pics on the Luna site and it appears that there is a drive-side plastic motor covering that hides the rats nest of connectors... the wires would ordinarily run out thru some kind of hole in that? Maybe in the back? And then route out as needed to their destination?

The holes allow you to route cabling in different directions under the mount and fwd out to their individual destinations? Did you replace the cabling with Higos to allow for those small holes? Looks like the stock connectors are JST based on what I am seeing at Luna.