This piece is really a discussion point over the Sharps helmet testing issue, If you are interested in reading this sort of stuff, let me know (david@bike-gear.com) above, and I may write some more.
Now, the Sharps test was hailed as the saviour for the Motorcycle retail industry. I suppose as to providing the answer to the question that why is one helmet is more expensive than another. We, as retailers, could then say that, (apart from it having a few bells and whistles in liners, visor working and venting etc etc) it had passed a new test with better results than the cheaper variety.
Well that did not happen, the £49.99 Box helmet got 4 stars when the Shoei XR-1000 got 3 stars and the Arai Condor only 2 stars! Even the Caberg Trip, a helmet that a traffic Police officer in the accident investigation dept I had spoken to at the BMF said was a helmet he had seen in pieces as a result of an RTA had got 5 stars!
Now the point I would like to make here is that the government Sharp tests have not got it right, for example, the way that a thermoplastic helmet deforms (it bends in and pops back out like a car bumper) at low speeds means that although it gives poorer results for the first impact, it gives the same (ish), poor result in the next two test on the same spot.
The multifibre helmet whether it is glass fibre, carbon, Kevlar , or a mix, is designed to crack and split and so spread the force around the helmet. These multi fibre helmets perform much better at the initial impact, but the performance deteriorates as you carry on. I was also told a slide test is not performed. I have been told that thermoplastic helmets melt slightly when in contact with the ground at speed which makes them likely to dig in or snag causing twisting injuries to the neck, fibreglass style ones slip consistently on tarmac. After all this don't forget also that the Sharps test is done at low speeds also, here is an extract from the site:
Test Speeds
An enhanced high and low speed test method was specified, based upon head injury severity. The COST 327, 2001 report recommended that impact velocity be raised from the current UN ECE Regulation 22.05 value of 7.5m/s to 8.4m/s, but to ensure that helmet performance was not compromised in the lower velocity impacts a 6.0m/s test was added. Performance limits would be strengthened and a new enhanced baseline level of performance formed. SHARP will test between 6.0m/s and 8.5m/s. To be consistent with the oblique impact test speed 8.5m/s has been selected, rather than the 8.4m/s proposed by COST.
Research indicated a strong recommendation to use 9.5m/s as the upper impact velocity. This may be too severe for many current production helmets. To ensure that protection at this velocity does not reduce, the performance of helmets at this test speed is being monitored.
Well correct me if I am wrong but gravity is 9.8m/s so is that relevant to an accident? If you notice the current ECE Rule 22.05 is at 7.5m/s, I would like to do a test and see if a plastic bucket passes at that speed.
Just a reminder, all helmets for sale in the U.K must have passed this ECE 22.05 test (there is an e mark inside), this test replaced the old BSI type A and B standards which had the blue and green stickers on the back.
My conclusion is that if I was riding a scooter it seems the plastic helmets are better? But a sports bike? Maybe a lower scoring model may be the way forward.
The guys on the back row of the BSB races do not get paid (usually) to wear any model of helmet, I will have a look next time at what they are wearing.
|
