I'm suspicious of this gadget myself, for just this reason. When fitting a bike helmet one must take pains to adjust it so that it won't slip backwards off the

I'm suspicious of this gadget myself, for just this reason. When fitting a bike helmet one must take pains to adjust it so that it won't slip backwards off the forehead when pushed. See e.g. http://www.consumersearch.com/bicycle-helmet-reviews/how-to-buy-a-bike-helmet http://www.consumersearch.com/bicycle-helmet-reviews/how-to-... In most crashes, the forehead and top front of the head strike first. Experts recommend buying a helmet that sits low on the forehead, about one finger-width above the brow.