Road safety charity Brake has called for helmets to be included in the Cycle Hire scheme, describing it as “imperative” that users wear them. They don’t, however, say how helmets would be factored in. And that’s the problem. The scheme as it is works because the bikes themselves are nigh on indestructible, and have no removable parts. Stick a helmet on each bike, and they’ll be missing within days. Despite the mayor’s words about the “terrifying things” committed by Boris bikers, TfL are adamant that it is up to the user whether s/he wears a helmet, as they’re not legally required. And were they made obligatory, the scheme might not work: Melbourne’s Bike Share has proved unpopular partly because state laws require riders to wear helmets.