Question: When did helmets become mandatory in the tour de france?
Answer: October 2003
Disambiguated annotations:
qaPairs: question: When did yellow helmets for the leading team become mandatory in the tour de france?
answer: 2012
question: What year did helmets become mandatory in the tour de france?
answer: 2003
question: After what event did helmets become mandatory in the tour de france?
answer: Kivilev's death