However, not all my rides warrant helmet use ( subject to my risk assessment of the ride in question) and (shock horror) I do ride a lot of my trail rides / park rides / 'traffic free' routes etc. without a lid. I've never found a long road ride etc. to pass the 'should I wear a lid or not' part of the risk assessment. So I've never done these rides without a lid, since the time I didn't risk asses the ride, and found out the hard way, why that's not always a great idea. I use a fairly simple model for my assessments, and thus far, it seems to have worked well.