Anyone have much experience using a KiddyBack backrest type of attachment. I am looking at this as an option for my 5/6 year old if I put him on the back of a tandem this coming summer.

Wondering how safe they might be?

How much weight can they support?

This past season he cycled all the time on a WeeHoo. The setup worked great, he was very safe and comfortable! He went on regular trips in the 15-20 mile range to the park or for ice cream. He also did several 50-75 mile trips through out the year, usually charity rides. I know he will want to continue doing these rides so I need to make bike adjustments to allow him to ride with me, so the tandem comes into the picture.

My big concerns on the back of the tandem are fatigue on longer trips and his strength/ability coming home from the park or at the end of a long day!

Any experience/advice?