Alan B wrote:Construction helmets are not designed to protect the head in a fall, and they are not designed to stay on in a fall. They do not meet requirements for the purpose and other than provide shade and airspace for cooling have little value as they will provide little to no protection in a fall as they come right off and are devoid of the energy absorbing foam that a rated helmet is equipped with.
True, they don't come with foam, but the one I have is unlikely to come off - unless it took my head with it.
And how much protection do you need? Certainly, a construction helmet is better than no helmet, and they're cheap and light.
Personally, as I already noted, I have the additional problem of having a rather large circumference head. I can get a cheap construction helmet (with a minor modification) to fit. I have yet to find a bike helmet that will.
Now, on the subject of mirrors, I'm now using both a handlebar mount and a helmet mount. I suggest someone should use this arrangement to evaluate the relative merits of the two positions. (I am, however, using a bit larger [5cm] mirror on the helmet than most use. Plus, the distance of the mirror from the helmet is important.)
It's easier to find a object behind me with the helmet mirror than the handlebar mirror. I doubt anybody using the same arrangement I have would disagree.