DOT vs. ECE Helmet Safety Standards

OFF THE WIRE
http://www.webbikeworld.com/eicma-2010/nolan-helmets/dot-vs-ece-helmet-safety-standards.htm DOT vs. ECE Helmet Safety Standards.
Motorcycle Helmet Safety Standards
by Rick Korchak for webBikeWorld.com
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Background
In Part 1 of this article, I described my detailed tour of the Nolan Helmets factory in Brembate di Sopra, Italy.
I learned about the polycarbonate motorcycle helmet manufacturing process and all of the work that it takes to create a Nolan helmet.
During my tour, I also visited a separate Nolan facility used for manufacturing the composite shells of the Nolan Group X-Lite helmets.
The process is completely different, although the painting and decal work is similar.
Nolan has developed many trade secrets for manufacturing their composite helmets and I was sworn to secrecy at the front gate, so unfortunately I'm not at liberty to discuss it.
However, I also visited the helmet safety standards test labs at Nolan, where both the polycarbonate and the composite X-Lite helmets are developed and tested and the designs certified to meet the various worldwide standards in the over 70 countries where Nolan helmets are sold.
I'd like to again thank the Nolan staff for providing this most excellent and enlightening tour and for allowing me such free access to the entire facility. And don't forget lunch!
Introduction
A huge amount of information -- or should I say misinformation -- exists regarding the differences between worldwide motorcycle helmet safety standards.
Unfortunately, even with all that information, there isn't a consensus among motorcycle riders on which standard provides the most protective, or "safest" helmet. Even the experts don't agree (and apparently don't really know) which test and what type of forces will optimize protection for the rider's head.
Another facet of this controversy is that many of the tests have apparently been developed without solid scientific evidence or backing for their efficacy, which has resulted in differences among the standards, such as the maximum G force over time that are called out. This is the source of some of the confusion; surely the criteriae and testing procedures among the standards would be similar if the data and evidence was available (and everyone agreed)?
Thus, the subject of motorcycle helmet safety standards is highly complex, so it's no wonder the general riding public is confused.
I wish I could say that I have learned enough to give you some concrete answers and facts on the differences. But although I've either owned or worn over 200 helmets in the last 10 years and am deeply immersed in the subject for a living, I'm still far from an expert on these matters. I pity the beginning rider that walks into the local shop to buy a first helmet.
Knowledge is power, so they say, but where there is power, there is danger. Too much or too little or misunderstandings are rife when it comes to helmet standards. So at the risk of adding even more confusion to the discussions, I'll convey some of the information gleaned during my visit to the Nolan labs and I will describe some of the rather surprising (at least to me) findings.
Notes and Disclaimers
This article is absolutely not designed to provide any type of definitive answers on this topic. I am far from an expert on this. It is simply one rider's observations on some of the differences and issues surrounding this complex subject.
Although I have labored to ensure that all of my facts and information are correct, it is possible that more clarification may be required, so contributions from readers who have expertise in the area of motorcycle helmet safety standards are welcomed and in fact, encouraged. It would be nice to develop a dialogue about this topic that could be shared with our readers.
OK, let's begin!
The Metalheads
Nolan has complete testing laboratory facilities that include drop rigs and all of the other technology needed to test helmets to all worldwide applicable safety standards. The facilities are also used for research and development on new designs, new materials and helmets for the Nolan, X-Lite and Grex lines of helmets that the Nolan Group produces.
Attached to the testing lab is Nolan's internal quality control facility, with all sorts of custom-made devices and machinery to "torture test" helmets, visor and face shield operation, sun shades and everything else that makes up a modern helmet. They even have an environmental test chamber to provide accelerated testing on moisture and humidity, temperature extremes and more.
The largest testing structures in the standards testing lab are the helmet drop test rigs. These are used to drop the helmets from a specified distance on to various metal devices, or "anvils", to measure the amount of energy absorbed by the helmet and liner.
In the drop test, a helmet is placed on a headform, which is a standardized metal form that is more or less in the shape of a human head. The design and weight of each headform is very specific and is called out in each standard.
The Headform
Which brings us to the first real difference in the DOT and ECE (and Australian) standards: the headforms are not the same shape. I might even say they're completely different, although there are specific technical reasons behind each design.
As you can see from the following photos (and in the video below), the DOT headform, on the right in the photos, looks wider and flatter. The ECE headform (on the left in the photo directly below) bears more of a resemblance to a human head shape, while the Australian headform is sort of a hybrid of the DOT and ECE shapes.
Headform Shapes, Rear View: DOT (left); Australian (Center); ECE (Right).
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Headform Sizes and Shapes
The DOT headform comes in three different sizes: S, M and L (reference the 571.218 standard information in the next section). Size small weighs 7.8 lbs. (3.5 kg); size medium weighs 11.0 lbs.(5.0 kg); and size large weighs 13.4 lbs. (6.1 kg). This range is designed to cover the estimated range of human head weights, which is said to range from about 3.5 kg to 5.0 kg.
Surprisingly, there doesn't seem to be a consensus on exact head weights or head dimensions vs. head size (but we all know that some human heads are much lighter than others, right?). In any case, for purposes of motorcycle helmet protection, I'd guess that a few grams here or there isn't going to make much of a difference. But what about those shapes?
The ECE headform comes in 8 different head sizes, ranging from size 50 to 62 with a mass of 3.1 kg for the size 50 to 6.1 kg for the size 62 (reference the ECE Standard No. 22 in the next section).
To summarize the headform differences, DOT uses three headforms and ECE uses eight. Their weight ranges are about the same. In theory, the ECE headform weights, spread across a larger range of headform sizes, might allow the helmet manufacturer to calibrate the EPS (expanded polystyrene) liner for the particular helmet size.
So which headform more accurately represents your head? Like most of the other issues surrounding motorcycle helmet protection standards, there really isn't an answer. I know of no studies that have compared the relative protection capabilities of the headforms (although such studies may exist), so it's difficult to say whether one approach is more valid than the other.
Headform Shape vs. Helmet Fit?
One other noticeable difference is in the shape of the headforms. The DOT, ECE and other helmet standards go into great detail on the size, weight, shape and construction of the headforms. Each headform has a large matrix of dimensions that are used to program the computer-controlled machine tools that make the headforms. This ensures the accuracy of the standard headform size and weight.
Looking at the headforms, the ECE shape appears to be narrower than the DOT shape. The DOT headform runs from 4.784 in. for the size small to 5.350 in. for the size medium to 5.720 in. for size large, while the ECE headforms range from 88.1 mm (3.4685 in.) for the size A to 108.7 mm (4.2795 in.) for size O -- quite a difference.
Again, I'm not sure what inferences can be drawn from these differences other than perhaps the narrower range of sizes for the ECE headforms may be in some way responsible for the differences we experience in the internal shape of ECE-only helmets? If the helmet is optimized for a specific headform shape, then it's possible that shape will carry over into the fit that the rider experiences.
DOT headform specifications (size M).
Standards and More Standards...
Monitoring changes to worldwide standards can be difficult, but motorcycle helmet safety standards are relatively stable, which is both good and bad news.
For example, the U.S. Department of Transportation, Federal Motor Carrier Safety Administration, Part 571, which contains the 571.218: Standard No. 218; Motorcycle Helmets that is colloquially known as the "DOT helmet safety standard", was first published under section 103 of the National Traffic and Motor Vehicle Safety Act of 1966 (reference).
Standard No. 218 was amended several times since then, with the last revision having been published way back in 1988 -- April 15th, to be exact.
Much has changed in the world since then, with technology, traffic and vehicle differences and in motorcycling and motorcycle helmets, so I'll leave it up to you to decide the merits of using a safety standard that hasn't changed in 22 years. Although I suppose we can look at the bright side and imagine that the standard is so good that it doesn't need to be changed, right?
Nevertheless, comparing the DOT and ECE standards is difficult at best and much like comparing apples and oranges. Depending on how you interpret the information, there are good points and not-so-good points about both standards.
And don't forget that DOT and ECE aren't the only helmet safety standards in the world. There is the Australian/New Zealand AS/NZS 1698:2006 standard; the Japanese JIS T 8133:2000 standard; the UK SHARP testing regime (info), which may or may not be a "standard" per se and more standards from Indonesia, India, Brazil and others.
By the way, the standard commonly referred to as "ECE 22.05" should probably more accurately be called "Regulation No. 22" because over 2 hours of searching while researching this article came up empty on any search results for "ECE 22.05".
This is discussed on the webBikeWorld ECE 22.05 information page, but to repeat, here is the page with .pdf downloads of the European motorcycle helmet safety standards.
And here is the direct link for the .pdf file of Regulation No. 22 "Protective Helmets and their visors for drivers and passengers of motor cycles and mopeds", which actually doesn't use the phrase "ECE 22.05", so I wonder where the term came from?