I have a 4 year old and a 9 month old. I am attempting to get the 4 year old a little more involved in his riding. I was wondering if getting him out of the trailer and on a trail a bike was a good option. I've never used or known anyone who has used one. Are they an exercise in futility or will he get something from it?? I know the trailer has to stay for the little one to ride with but maybe the larger could help with a little peddling? ? Not sure any ideas out there??