I decided to do some searches regarding helmet safety, I found this interesting site that has information on both sides of the coin, here’s an example:
Evidence that helmets are effective
*Case-control studies generally support helmet use. The most widely-publicised studies claim that helmets reduce 90% of fatalities, 85% of head injuries and 88% of brain injuries.*Literature reviews of medical evidence. These are based almost exclusively on case-control studies, and generally on the same subset of such studies.
*”A helmet saved my life”. The experiences of helmeted cyclists who have hit their heads in a crash and believe that their helmet has saved them from injury.
Evidence that casts doubt upon helmet efficacy
*Casualty trends from countries and towns where helmet use has become significant show no reductions in serious or fatal injuries attributable to helmets. In many cases the number or severity of injuries has increased.*In USA, an increase in helmet-wearing from 18% to 50% of cyclists was accompanied by an increase in risk of head injury of 40%.
*Helmet laws in Australia and New Zealand have resulted in the great majority of cyclists wearing helmets, but there has been no reduction in rates of head injury relative to cycle use. Some data suggests these have increased.
*Detailed analysis of key case-control studies has highlighted serious flaws and methodological shortcomings.
Helmeted cyclists have been shown to be more likely to hit their heads if they crash and may be more likely to crash in the first place.*Senior neurosurgeons have given evidence to court that helmets are only effective in preventing minor scalp lacerations and not more serious injuries.
*A prominent helmet test expert says most helmets are incapable of sustaining impacts of the type associated with serious crashes; helmets provide protection only in low impact crashes under favourable circumstances.
Medical evidence suggests that most serious head injuries sustained in road crashes are due to rotational forces, which cycle helmets do not mitigate. There is some evidence that cycle helmets may increase the likelihood of this type of injury.Source: www.cyclehelmets.org
So now that everything is clear as mud, is a cheaper helmet as safe as an expensive helmet? It is assumed that the reason why a helmet is so expensive is because of the number of vents and its design, but are more vents safer?
Here’s an exerpt from www.helmets.org:
Vents are Hot!
A major theme in the helmet market since 1997 has been more and larger air vents. All major manufacturers now have hyper-ventilated models following in the footsteps of Giro’s 1997 Helios model (now discontinued). Manufacturers tout the number of vents in their helmets, a meaningless parameter. If all else were equal, more vents would be a Good Thing, but as usual, all else is not equal. Unfortunately opening up new vents usually requires harder, more dense foam and squaring off the edges of the remaining foam ribs to squeeze out the most impact protection possible from the narrower pieces still there. Since we believe that rounder shells and less dense foam are virtues in a crash, we don’t recommend hyper-vented helmets unless you can’t live without the added ventilation.
From a personal experience, I haven’t had the necessity to test my helmets while commuting or riding on the road (no, I will not test them unnecessarily) but and even though I had my spills while riding off road, I can’t really say that my helmets have saved me since I have never landed on my head. Does a helmet make me feel safer and therefore braver? I can’t say they do, all I know that if a helmet has a 1% better chance of saving my butt and getting me home to my family, its a damn good 1%.