unless it was meant for two and has a seat and foot rest for a passenger its illegal to ride double. its more a safety concern than anything! I remember when I was 5 and the neighbor girl decicded to put me on the bicycle rack for a ride and got my foot ate up by the spokes. ouch that hurt, I looked down and saw blood. the other neighbor saw this and ran over and scooped me up from the road and ran me home. my foot and especially my big toe was skinned up real good and have a scar to show to this day.