Originally Posted by
yugo campione
A question still remains unanswered in what you put forth. Maybe you can add insight, how do the number of people killed, or with severe head trauma, compare with say, auto accidents, or shower falls, or just walking and tripping? All those, as well as countless other activities, I'm sure offer significant potential for head injuries, yet it is not common at all for anyone to wear a helmet during those activities. Do you wear a helmet when you drive? Why not? I am willing to wager that there are far more head traumas due to auto accidents than bicycling every year. Am I wrong? If I am not wrong, why do you, specifically, not wear a helmet everytime you get behind the wheel of your car?
Well if you're looking at it from an activity standpoint you need to look at it from a per participant per hour aspect. I think driving or riding in an automobile actually turns out to be safer statistically.
If you're looking at it from a commuting standpoint you'll need to assess head injuries per participant per mile.
From what I've seen there is just no really good data for cycling. Data is usually collected from hospital admissions. All kinds of cyclists end up in the hospital and everyone from BMX kids doing stunts at the skatepark to DH MTBers to MUPers who ride 20 miles per year on poorly maintained rigs really skew the stats.
You really have to go with your gut and your perceived risk. When in doubt, wear a helmet.