bandaidman,

Our 6 yo daughter was nervous on the trailer bike at first, but after a couple of rides she loved it. Our 4 yo son didn't have second thoughts and took right to it. You may want to either get a mirror to watch them (our boy does stuff like puts his feet on the handlebars, hops off before we stop, etc..) or alternate taking turns at the front so you can observe the kids behavior. Also, we bought cheap bike computers and mounted these to each trailer bike to give them something to do and talk about.

pucci,

Some will say you get what you pay for, but regardless I have been very pleased with our Trek Mtn Trains (we have two). We bought these a little over a year ago and use them about once a month on average and they are holding up fine.