They were out today on the South side of London Bridge. I was waiting to turn right over the bridge at the end of Tooley St, and a plump Geordie copper says to me, "No helmet, like?" I told him I was the wrong person to be having that debate with. He claimed to have made the acquaintance of a number of brain surgeons who had shared their wisdom on the topic of cycle helmets. I suggested he make efforts to engage with accident researchers and statisticians.