It’s a tricky one. I don’t know what the laws are in the UK any more, but I suppose helmets should be mandatory for under 16/18 year olds, as they aren’t ‘responsible’, and should have protection regardless of what their parents think, but for adults - well, it’s your head. I always wear one, and it gets stupidly hot out here, but I like descending fast and that’s my choice. I suppose the argument for mandatory helmets is the cost of treatment for those in accidents without one? Any other reason? To stop a driver feeling bad if they kill a cyclist without a helmet lol?