JB got me looking into Suomy helmets. Just to get this in the record, this is the FAQ section from the Suomy site . . . it relates to the BSI standard to which Suomy builds their helmets:
https://www.suomyusa.com/ssafetya.htm. I have no dog in this fight, just passing it along . . .
A couple of snips
1. What is BSI?
a. BSI is one of the largest and most prestigious standards, quality assurance, inspection, testing and certification organizations in the world. Similar to the familiar UL Listing, the BSI offers testing and rating services for major manufactures with worldwide distribution interests. The BSI Inspectorate is a leading provider of inspection, analysis and testing services across the globe. A vital business within the BSI Group, BSI Inspectorate delivers confidence for buyers and sellers alike, as well as banks and governments involved in international trade the world over.
9. Is it true that Suomy BSI certified helmets are over 300 grams lighter than the Suomy helmet certified to the Snell standard and if so, why?
a. Yes! A BSI certified Suomy helmet might be as much as 300 grams lighter than it.s Snell counterpart (we manufacture OEM helmets for Ducati and Aprilia to the Snell standard). The difference is merited out of the variances between the two standards protocols. These testing protocols may vary in such ways as head form weight, falling mass, measurements such as the distance velocity is measured above the impact site, velocity at point of impact and drop heights. The significant deviation between Snell and the BSI Type A is in the second drop height, with Snell.s second drop being higher than BSI.s second drop (most experts will agree that the second impact drop height for Snell is not relevant to motorcycling but reflects the particular demands of auto racing where the driver.s head may impact a roll cage several times during a crash). This differentiation results in a lighter, less rigid outer shell requirement to pass the demanding BSI 6658 Type A test. This decrease in shell rigidity allows the helmet to work in concert with the EPS system (expanded polystyrene) to better mitigate energies experienced at speeds where the rigid shell of the Snell configuration can fall short, without compromising the fundamental energy management of much higher energy loads. A helmet that performs to the standard at the lightest possible weight reduces total pivoting mass, head deceleration and will tire rider less, thus increasing safety. In addition, lighter helmets are more likely to be worn and wearing one is the single critical factor in the prevention of and reduction in head injury. (Source . The HURT Report Summary, Line #45 - www.cs.wisc.edu/~john/vfr/hurt.html University Of Wisconsin).
10. If the BSI standard is so good, why not simply build the helmet to meet both the BSI 6658 Type A and Snell 2000 standard as well, and avoid any confusion?
a. As mentioned above, the major deviation between the two standards in found in the second drop height. This requirement forces the manufacturer to build a much stiffer outer shell to perform well in the Snell 2000 second drop impact tests. This stiffer shell requirement may also prevent the helmet from passing the BSI 6658 Type A standard, by not allowing the helmet to start absorbing energy until a much higher threshold. By not allowing the helmet to begin managing energy at the typical speeds and energies a rider is most likely to experience, the Snell 2000 is counter intuitive to the BSI 6658 Type A.
11. What is the essential difference between the mandatory DOT standard and the voluntary standards such as Snell and BSI 6658 Type A?
a. While there are several significant differences between the DOT standard and other voluntary standards, the key difference has to do with something called .Dwell Time.. Dwell Time is best expressed as the duration in time above a pre-determined deceleration that the head, or brain is experiencing during impact. The DOT specification calls out a maximum allowable deceleration of 400g from a drop height of 1.8 meters with sustained energies above 200g to not exceed 2 milliseconds and 4 milliseconds above 150g. This energy duration, or dwell time, is an important consideration in preventing brain injuries at the anticipated energies a rider might experience in a fall. Both BSI 6658 Type A and Snell 2000 require a maximum deceleration of 300g, (a 100 G force reduction) but have no .dwell time. component built into the standard. However, it is important to note that while neither BSI Type A, nor Snell 2000 have a dwell time component, each standard MUST pass the DOT 218 dwell time requirement to be considered legal for street use in the USA.
12. How well do Snell and BSI Type A helmets comply with this Dwell Time requirement?
a. Suomy helmets built to the BSI 6658 Type A standard perform extremely well in the Dwell Time test, while helmets built to Snell 2000 may not perform as well due to the stiffer outer shell the standard mandates. Due to Snell.s post public release testing and for reasons previously mentioned above, some helmets manufactured to the Snell standard may not pass the DOT compliance test (Reference . National Highway Traffic Safety Administration .
DOT Performance Compliance Test results:
https://www.nhtsa.dot.gov/cars/testing/comp...218/index.html). However, with the BSI pre factory release batch testing, helping to ensure compliance, a DOT failure is highly unlikely.
13. I understand that BSI 6658 Type A and Snell M2000 are the only nationally recognized racing standards in the USA. But I don.t race. Is a Snell or BSI Type A certified helmet safer than a DOT certified helmet for my street riding?
a. While the Snell standard is recognized by the general public as superior to DOT for the racing community, many experts believe that a helmet manufactured to the DOT standard is actually safer for street riding than a helmet manufactured specifically to the Snell standard. At first Glance this might seem illogical, after all if Snell is good enough for racers than it must be better for street riders, right? This is not always the case! With the Median motorcycle street accident being just 29.8 MPH prior to impact, (Source . The HURT Report Summary, Line #15 -
https://www.cs.wisc.edu/~john/vfr/hurt.html University Of Wisconsin), and many impacts being a glancing blow to the side of the head, a typical Snell certified helmet might not experience ENOUGH energy to properly dissipate the energy being transmitted to the head (this is a result of the heavier and stiffer outer shell that the higher Snell second drop on a hemi anvil requires). This may result in unnecessary concussion or head injury. Suomy helmets built to the demanding BSI Type A standard have built in features that provide for extremely favorable DOT test performance as well as the more demanding requirements of the BSI Type A standard, and each Suomy BSI certified helmet is batch tested for performance compliance prior to public release to help ensure that your Suomy BSI 6658 Type A approved helmet passes both the BSI test as well as the mandatory DOT tests.
1. You mention that many helmet impacts are a .glancing blow. to the side of the head. How do BSI and Snell test for this important and common type of impact?
a. The BSI 6658 Type A utilizes two unique impact energy management tests to ensure the helmet will perform when asked to. In the first test the helmet is impacted against a bar anvil to assess projections from the general shape of the shell and in the second test the helmet is impacted against an abrasive pad. These tests are utilized to ensure that the helmet will not have any design features that could catch and twist the rider.s neck. Interestingly, Snell does not test for either of these Oblique Impacts.
See also the following references:
BSI - .
https://www.bsi-global.com/index.xalter
Snell Memorial Foundation -
https://www.smf.org/
National Highway Traffic Safety Administration . DOT Performance Compliance Test results:
https://www.nhtsa.dot.gov/cars/testing/comp...s218/index.html
The HURT Report Summary - www.cs.wisc.edu/~john/vfr/hurt.html
Head Protection Research laboratory -
https://www.hprl.org
Re: "A New Helmet Standard" CYCLE WORLD MAGAZINE October 2002 page 34