Jacques Moser wrote:

For someone who has wants to commute with a combination of bike and
public transportation, I wonder if it would be an option to have two
inexpensive bikes, one at each end of the trip ?

How would that help? If you can't comfortably get one bike on a train, having
a second in another place isn't going to change anything. If you go one way by
train and walking and then return by bike, you just have two bikes in one
place. Moreover, I already have two bikes. What I want is a third with special
qualities - lightness, transportability, 20" wheels, a wide gear range - that
neither of the others have.

EFR
Ile de France