When my child falls asleep in the child seat, his head falls forward.
How can I keep his head back?
The child seat is a modern type with a back that can be tilted back to prevent that. It works, but only as long as the bike isn't moving. But at speed, the seat's movements from an uneven road surface and from simply pedalling will slowly but surely make his head fall forward. Short of replacing the child seat with one whose back can be angled even further back, what options do I have?
I thought of the whiplash protectors used in Formula 1 cars: somehow strap the child's helmet to the seat back. But that would be neither safe nor effective, as such a strap would only tug at the helmet (not the head) with the risk of slow suffocation or at least a helmet that slides into the neck and would no longer protect the head in case of an accident.
Let me add a fun photo: here, a cloth bag is hung from the helmet in an attempt to keep the child's head from falling forward. We did NOT actually do that, but it shows the idea.