bafang stuck in frame

[jpc6000]

I don't get it out of the frame the bafang bbs02
Place it a couple of months ago
when i remove the bolt I used more the 100 nm
I use penetrating oil
I used soft hammer, to get it out, but even that don't change anything
I hammer so much that even the thread of the motor is damaged
I use cowbar, little bit it goes down
That's the first time that I have this and nothing to find on google

 

[fechter]

That looks ugly! Probably rusted in.
If you can twist the motor a little, you may get it to break loose. Pry between the frame and the motor housing to get a little movement. A little heat might help too, but be careful not to heat too much.

 

[Wattman]

Couple of things...
Lay the bike over on the drive side. Remove the crank arm from the drive side.
Use PB Blaster and literally fill the crevice between BB shell and OD of Bafang mid drive spindle body.
Let soak over night and repeat for another day filling the crevice with PB Blaster. Place a large rag and plastic under the motor to catch the PB blaster which will run through.

Next time you try, get a buddy or two to help with the bike laid over on the drive side creating clearance between the motor and floor, apply heat...like MAP gas to the BB shell. Aluminum has a higher rate of thermal expansion compared to steel. Try to expand the BB shell ID.
Place a block of wood against the spindle and use a 3 lb sledge hammer. Don't wail on it. Start with love taps and increase loading. Stucatto force always works better than a dull press.

When you get it apart, clean up the ID of the shell with sandpaper or dremmel and create a semi polish and enough clearance so it goes together easily.
P.S. A slightly gentler approach...is find a block of wood that is deeper than the spindle protruding from the spindle body where you buggered the thread a bit. Drill a hole in the wood the same diameter as the square taper. Use the wood to press against the motor spindle body and not the spindle which is bad for the bearings which aren't designed to take much trust loading and held in with a circlip.
This is what I would do. Also if possible, implement what Fetcher said just above. If you have a real strong friend use him to rotate the motor if possible to break the galvanic corrosive bond.
Before getting aggressive, always best to start conservative.

 

[E-HP]

A couple of thoughts.

1. Might be able to get a gear puller on there to press it out.
2. The heat idea is good, but you can also use heat and cold. If you have the ability to throw the thing a the deep freeze, then heat the shell, that might do it. I've done that with parts there were press fit together, steel inserted into aluminum. If you don't have a deep freezer big enough, then you could use a freeze spray to cool down the spindle, then apply heat to the shell Amazon.com : freeze spray (or maybe the weather is cold enough to let it sit outside and cool down)

 

[jpc6000]

I removed the inside of the motor and with wooden hammer in the front
ge starts moving down, and after a while up and down he become looser and looser
after grinding the front, its already for the bin, and a lot of penetring oil, in and out and after a hour he was loose.

The motor housing is not repairable
and never seen to sell
maybe second hands

I have an old bafang, never used bbs01 and it seems to fit, with the 750 watt version, even its an old versions

To prevent that happen again?
I use 80nm for the bolt holding the motor, because of loosingen the motor, and then this happen
its also not because of this, maybe filt and water
I shalll clean the inside and 60nm force

 

[Wattman]

Nut torque has little to do with what happened here. Btw, best installations use anti rotation bracket which allow a much lower torque on the nut to keep the motor from rotating down due to gravity.
What matters from the beginning is fit of the motor spindle body to the ID of the BB shell. If a slip fit, it will generally come apart with penetrating oil and bit of heat.
You would be surprised what can be repaired but takes some craftsmanship. For example, some even change spindle length by re-pinning a new spindle body to a BBxxx motor.