Feb 12, 2008

Helmet Visors: What's that stuff written on them?

AGVIf you look carefully at the shield on your AGV/KBC/Sparx/Shoei, you will see a small piece of text that reads "EXCEEDS VESC-8." The other day, after months of procrastination, I finally got around to figuring what that cryptic thing means. VESC was an American Vehicle Safety organisation, and the VESC-8 is a standard they created that sets the norm for protective eye gear. While the organisation itself is defunct now, its standard has been adopted more or less everywhere.

I am unable to source the document itself, but I chanced upon a study [pdf]that compares various helmet standards and therein I found that VESC-8 fires a 44.2 gm metal dart at the protective eye gear (visor) from a height of 4.27 metres. If the dart penetrates the shield, it fails the test. SNELL, meanwhile, fire 1 gram, 5mm dia led pellets at a shield at 500 kph (true!). The pellets are allowed to leave bumps in the visor but if one penetrates... failed. Similarly, the ECE 22.05 and DOT also have some sort of performance criteria for a helmet shield, which can lead to an entire helmet flunking certification if the shield alone fails.

Which brings me to the Indian visor standard. It irks me that IS 9973 is officially the 'Specification for Visor for Scooter Helmets" but that aside it does have all the right stuff in it. There are two performance tests and a bunch of optical tests. The first performance tests sees the shield mouted horizontally. A 50 gram 'steel sphericals ball' is dropped on the sheid from a metre hieght. The shield is supposed to neither shatter, nor come unhinged. The second test uses a sewing machine needle backed by a 50 gram weight. This too is dropped from a metre high, and again is expected to not penetrate the shield. Unlike the helmets, there is no heat/cold requirement. Also,the visor is expected to be visually perfect and come with a tag that tells you to keep it clean. Finally, it may carry an ISI mark (not to be confused with the IS 4151 for the helmet itself) on it.

In India, AGV, Sparx and KBC are the only helmets that come with VESC-8 spec shields.

5 comments:

subhash said...

These pins and balls are crazy stuff. Why cant they just throw the helmet at 200kmph – 100 for the helmet/vehicle and 100 for a vehicle in the opposite direction – and measure the impact on the shell and visor! This is more realistic measurement than some pins and balls. A biker ramming into an oncoming truck is more probable than ramming into a hardware store 

EvolutioN said...

and you are gone again!

pins and balls? what the!!!!

Anonymous said...

I would like to comment to the above two gentlemen that they do a little more research themselves before they make such absurd statements.

The component in question is visor.

From the article (for the benefit of those who think they are safety experts):
The VESC test employs a steel dart, 44.2g (1.56oz) in a free fall from
4.27m (14 ft) to contact the optically qualified eye covering without permanent intrusion. This
gives a minimum level of protection from small objects contacting the face shield at 9.15 m/s (30
fps). It is important to note that research has shown that the value of helmet faceshields lies
primarily in the preservation of vision, not impact protection.

And to Rearset:
Thanks. Very Informative, appreciate the hard work into educating us.

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Sashi said...

Hi man,

But I cant find a store in bangalore for SPARX helmets. Is there any website that would give the address where I can get these helmets??

Sashi