Yep, DS1 always has to wear a helmet on his bike or scooter. We don't have a yard, but this applies whether he is riding on the balcony, in a park, or on the footpath. It's about instilling that habit and having a consistent rule.
I also don't see what the harm is in having him wear a helmet. It takes a few seconds to put it on. There are other "risky" things I let him do like climb trees, monkey bars etc but that's because I can see there is a benefit for his physical/cognitive development in doing those things. I can't see how having to wear his helmet when riding his bike is limiting his opportunities or development.
ETA: this was also the rule in our house growing up in the 80s
Edited by ekbaby, 09 December 2012 - 09:14 PM.