Thank you for your recommendations!
It is wise for peoples who drive a lot.
I am not that person.
For me it's a project, the different one from others.
I like idea to make "projects".
My friends do the same.
One makes boat, other electric car, drones, e.t.c.
It is our "men's world".
This version of friction bike is interesting. My calculations tell to me, I can drive 60 km on one charge, because motor help me go fast and that is reason why battery last long. Without motor my speed drop to 20km/h and it is much harder to do the ride. With motor activated I can drive with "feelings". Very nice.
And yes, my "projects" are "cheep" in the base.
Sometimes they are successfull, sometimes not!