@amir: "Helmet compulsion can be quarrelled over elsewhere."
I expect most people worked out their position on Spokes' decision within the first couple of pages of this thread. The rest is an unframed debate on helmets. As the people this most affects we deserve better than to do this to ourselves. If we really want a helmet debate, let's break it down into the various issues - the research, the physics, the social pressures, the law, the threat of legislation etc. etc. and deal with them separately. I think the end result might be that we realise that there are no sides to the debate at all.