continued from above
****Warning gross paragraph to ensue, but informative****
"The Wayne State Tolerance Curve is the result of a pretty gruesome series of experiments back in the '50s and '60s in which dogs' brains were blasted with bursts of compressed air, monkeys were bashed on the skull, and the heads of dead people were dropped to see just how hard they could be hit before big-time injury set in...The two tolerance curves agree on how many Gs you can apply to a human head for how long before a concussion or other more serious brain injury occurs. And the Wayne State Tolerance Curve was instrumental in creating the DOT helmet standard, with its relatively low G-force allowance.
According to both these curves, exposing a human head to a force over 200 Gs for more than 2 milliseconds is what medical experts refer to as "bad.""
and now on to DOT...
"In the other corner of the U.S. helmet cage-fighting octagon is the DOT standard. It mandates a testing regimen of moderate-energy impacts, which happen in 90 percent or more of actual accidents, according to the Hurt Report and other, more recent studies.
...
Where the Snell standard limits peak linear acceleration to 300 G, the DOT effectively limits peak Gs to 250. Softer impacts, lower G tolerance. In short, a kinder, gentler standard.
The DOT standard has acquired something of a low-rent reputation for a number of reasons. First, it comes from the Gubmint, and the Gubmint, as we know, can't do anything right.
The DOT standard, like laws against, say, murder, also relies on the honor system; that is, there's only a penalty involved if you break it and sell a non-complying helmet and get caught. Manufacturers are required to do their own testing and then certify that their helmets meet the standards"
info on types of crashes and what should be protected speeds for impacts etc.
"First, about half of all serious motorcycle accidents happen when a car pulls in front of a bike in traffic. These accidents typically happen at very low speeds, with a typical impact velocity, after all the braking and skidding, below 25 mph.
...Actual crash speeds are slow, but the damage isn't. These are serious, often fatal crashes
...The next-biggest group of typical accidents happens at night, often on a weekend, at higher speeds. They are much more likely to involve alcohol, and often take place when a rider goes off the road alone. These two groups of accidents account for almost 75 percent of all serious crashes.
...Another eye-opener: In spite of what one might assume, the speed at which an accident starts does not necessarily correlate to the impact the head—or helmet—will have to absorb in a crash
...How can this be? Because the vast majority of head impacts occur when the rider falls off his bike and simply hits his head on the flat road surface. The biggest impact in a given crash will typically happen on that first contact, and the energy is proportional to the height from which the rider falls—not his forward speed at the time. A big highside may give a rider some extra altitude, but rarely higher than 8 feet.
...In fact, the vast majority of crashed helmets examined in the Hurt Report showed that they had absorbed about the same impact you'd receive if you simply tipped over while standing, like a bowling pin, and hit your head on the pavement. Ninety-plus percent of the head impacts surveyed, in fact, were equal to or less than the force involved in a 7-foot drop. And 99 percent of the impacts were at or below the energy of a 10-foot drop"
Sorry soooo long, but tryign to condense like 10 pages into one message here, in a manner that might cause others to research this VERY critical issue themselves...
I have made the decision, and I am a safety freak!!!!
Here are the parting comments in summary of the article
"How many people were saved because their helmet was designed to a "higher" or "higher energy" standard than the DOT standard? As far as the Hurt researchers could ascertain, none. "
"The COST 327 results showed that some very serious and potentially fatal head injuries can occur at impact levels that stiffer current helmet standards—such as Snell M2000 and M2005—allow helmets to exceed."
And here is the one that pushed me to a non snell helmet...The scientist who studies this, or Joe wrencher who plays with your clutch...
"If you ask most head-impact scientists or the representatives of the European helmet manufacturers how they like the Snell M2000/M2005 standard, they will generally tell you it's unrealistic, based more on supposition than on science, and forces manufacturers to make helmets that are stiffer than they should be.
If you ask the representatives of many of the top Snell-approved helmet companies, they'll say the Snell standard is a wonderful thing, and they'll imply helmets certified to lower-energy standards—that would be any other standard in the world—are suspicious objects, like smoked clams from the 99 Cents Only store. And not as good at protecting you in an extremely high-energy mega-crash as a Snell-approved helmet is. "
So, here is the finale... the standard that the bike helmets, specifically the one I bought comply with two primary standards...
ASTM f2040 and CE EN 1077...the ASTM f2040 does the same drop testing but from a few feet less than the MX style...it creates 96.1% of the force that Snell tests too...
"In our new results, no helmet exceeded 250 Gs in the 10-foot drop, and the vast majority of the 7-foot drops stayed well below 200 Gs. So falling at a 10-foot energy level today—a 99th-percentile crash—is like falling at a 7-foot energy level was back in '91"
safety is all percentages...and if I can be just as safe for 99.987% of the situations I will be in with a significantly lighter gourd cover, I am all for it!!!
but as I said, this is just me, and this is some of the detail I have studied, advise all study for themselves, and read for themselves on this critical subject...
All I do is boondocking and mountain riding and I always considered my helmet as a head warmer. That was until my sled came over on top of me!! I was going down a steep decline and the skis caught and the sled came right on top of me. Track and tunnel landed squarely on my head. Gave me a black eye, and scraped up face. Completely tore up the helmet. You can see the stress fractures on the face mask and where the paint came off. I was only going 15 to 20 miles and hour. 
