"I don't think the kid would be putting forth any useful power, but learning to shift is good. and if they get bored they will have something to play with."
respectfully, i disagree with these comments-
useful power- you can easily feel the "power" from a small stoker. on a flat road the stoker can keep
you both moving along nicely.
learning to shift- should come at a later date when the child is fully coordinated to be effective at this.
bored- if you stoker child get bored, you should stop and let the bored person get off.
something to play with- better for the stoker to keep both hands on the handlebar, we had a couple
close calls where the stoker was one handed and started to loose his balance.
the stoker helped keep track of traffic, a mirror was very helpful, one for each of you. the stoker
likes to look into your mirror and see your face- it helps keep him/her connected and seemed to
help with stoker communication