Wearing a helmet is a must!
Ah, but the mitzvah of wearing a hat (a yehoraig v’al ya’avor, certainly) is doche the silly helmet rule (which is only dina d’malchusa dina anyway). 🙂
Kidding aside, you’re absolutely right. Helmets are a must. My kids don’t go biking without them. I’m glad to see your R”Y enforcing the point.
The Wolf