What does the mount angle setting do?

[FixThatBike]

I use Stunlocker. I've seen various discussion of the motor mount angle setting, but I haven't seen a description of what it actually does. Does anybody know?

It seems like the motor should be applying consistent power (relative to your pedaling) around the axis. I can't figure out how the mount angle would change anything.

 

[Gary]

it just increases assistance of the utterly pointless "walk" mode feature. slightly.

RTFM

 

[FixThatBike]

I did RTFM. The FM makes no sense to me.

Why would the amount of power the motor needs to put out depend on the mount angle at all? It's spinning the cranks. Even if the motor was upside down, the power around the BB axis would be the same.

 

[Gary]

Page 21. apendix IX

https://www.stunlocker.com/doc/ST_Manual.pdf

maybe ask a friend to help

 

[Gary]

Why would the amount of power the motor needs to put out depend on the mount angle at all? It's spinning the cranks. Even if the motor was upside down, the power around the BB axis would be the same.

Do you want time to think about that in relation to "walk" mode?
Or do I have to state the obvious?

 

[FixThatBike]

Gary - If you don't know the answer, you can just say you don't know. If you do know, please enlighten the rest of us that weren't lucky enough to have been bestowed the amazing brain that you got.

 

[Gary]

FFS

Basic physics
as gradient increases any wheeled vehicle will require a greater force to continue moving forwards at the same speed.
The motor angle setting is just there so the motor's operating software can calibrate a starting point (ie. when the bike is on level ground).
in reality the setting will make little difference. Especially if you struggle to grasp this basic principle.

The only amazing thing about my brain is that it even works at all after sustaining so many head injuries.

 

[FixThatBike]

Huh, you think the motor attempts to vary the power in walk mode based on the grade it thinks the bike is on. I am skeptical of this, but I at least understand the theory. Thanks for the explanation.

 

[steve_sordy]

...............
The only amazing thing about my brain is that it even works at all after sustaining so many head injuries.

That explains a lot.

 

[Spiff]

The theories about the motor angle and "walk mode" are good, but the motor angle is also important for the motor normal assistance, the motor needs to know the angle at which the rider starts pushing the pedals and providing "human torque" so the motor modulates its power each revolution according the rider's torque input.

Also, if motor angle is not set correctly, motor does not provide assistance at all, not only in "walk mode"

 

[jimbob]

The theories about the motor angle and "walk mode" are good, but the motor angle is also important for the motor normal assistance, the motor needs to know the angle at which the rider starts pushing the pedals and providing "human torque" so the motor modulates its power each revolution according the rider's torque input.

Also, if motor angle is not set correctly, motor does not provide assistance at all, not only in "walk mode"

I was told by my LBS who is a shimano service center it affects the torque sensor, so if not set correctly will give either too much or too little power under normal mode.

Not convinced it alters the walk mode power based on gradient, but could well be wrong! That's just based on them not being able to make a motor or battery which lasts, so why would they get something that complicated right..?