success
Tried it this morning for the three mile ride and it seemed to work just fine. I made sure to attach the trail-a-bike so it was roughly the same height from the ground as when its on my 26in wheeled mtn bike and this solved any problem of the pedals not clearing the ground. I also don't take many sharp or fast turns with my 5 year old on the bakc. In terms of the seat post bending, Dahon Helios comes with a very sturdy seatpost of substantially greater diameter than the standard. don't see it bending. clamping a thin piece of rubber underneath the mounting mechanism, keeps it from slipping down the post.