a few years ago i was at LBS to pick up a bike post tune up, my 5 yr old son adam was along.
the LBS had an adams trailer bike hanging in the used bike rack. he thought that was his new
bike, between the LBS and Adam; felt like i was set up. so the adams trailer came home and
we mounted it on my mud bike. i don't think the gearing really mattered for the 5 yr old,
being able to ride a "big bike" with mom and dad was more important. he would pedal when he
wanted and coast when ever. sometimes on a level smooth surface, dad would say adam
"pedal for us", adam would pedal and dad wouldn't- adam got a great charge out of being the
"power". things to watch out for- make sure you have a mirror on your bike so you can watch
the rear stoker. also put a mirror on the trailer bike so the rear stoker can look around more.
adam was always cranking his head around to look at something along the road or mom, this would
shift his weight slightly, the front bike feels that a lot. we never rode very long, 1/2 hr at most,
as the stoker would get tired and lose interest. make sure the stoker has some eye protection,
dust and stones seemed to target the back. our stoker will be 8 in a couple weeks, he has his
own bike, is excited about biking and seems to enjoy riding (during the past couple months
he has asked to "get his bike out of the shed?, so he can ride in the snow)- i think the adams trailer was a great contribution to this.