+1Steve Austin said:I don't think this thread should turn into 'is it worth wearing a helmet?' or 'will a helmet save my life?'
but i always reckon if you are going to wear something that 'might' help you in the event of an accident, then it is worth using a helmet that isn't knackered from old age
There are suggestions that newer designs are far from "better" and older helmet designs are safer!Steve Austin said:also, technology moves fast. the older the helmet, the older the technology.
Not to say that the newest helmets are better, but its worth adding that into the equation
During the last couple of years, the technical staff at HPRL has encountered an interesting-and possibly dangerous-problem with the aerodynamic-shaped or streamlined bicycle helmets. These popular helmets have a teardrop design which tapers to a wedge at the rear of the helmet, supposedly reducing aerodynamic drag along with increased ventilation through the many openings in the shell.
The adverse effect of this aerodynamic shape is that the wedge at the back of the helmet tends to deflect and rotate the helmet on the head when impact occurs there. Any impact at the front or sides of the streamlined helmet is no different from other helmet shapes, but any impact on the rear wedge tends to rotate the helmet on the head, probably deflecting the helmet to expose the bare head to impact, and at worst ejecting the helmet completely from the head. Actually, everybody who has tested these streamlined helmets over the past years has encountered the problem of these helmets being displaced during impact testing at the rear wedge. Usually additional tape was required to maintain the helmet in place during rear impact tests; usually the basic retention system alone could not keep the helmet in place during impact testing on the rear of the helmet.
Unfortunately, the implication of helmet displacement and possible ejection in an actual accident impact did not register as a real hazard in previous years of testing, but now there are accident cases appearing that show this to be a genuine hazard for bicycle riders wearing these streamlined helmets. Accident impacts at the rear of these streamlined helmets can cause the helmet to rotate away and expose the head to injury, or eject the helmet completely. The forces generated from the wedge effect can stretch the chinstraps very easily, and even break the [occipital--Prof. Hurt used a trademarked name] retention devices.
We request that F08.53 committee study this problem and develop advisory information for both manufacturers of these streamlined helmets and consumer bicyclists who now own and wear such helmets. There is a definite hazard for displacement or ejection from impact on the rear wedge of these helmets, and bicyclists should be warned of this danger by an authority such as ASTM.
s/Hugh H. Hurt, Jr
President, Head Protection Research Laboratory
s/Christopher B. Swanson
Laboratory Manager, Head Protection Research Laboratory
Abus:Helmet crash replacement Policy
If a helmet is damaged during a crash within 2 years after the purchase date, the Specialized dealer will replace this helmet for 50% of the original purchase price. Therefore, the dealer needs an original proof of purchase and the damaged helmet.
Giro:The ABUS Crash Replacement Scheme
If you ride an ABUS helmet and have a crash whilst wearing it, you can take advantage of the ABUS Crash Replacement Scheme if the helmet is less than 3 years old from the date of purchase (proof of purchase required). You are able to buy an equivalent replacement helmet at a reduced price or the equivalent replacement model, should your model no longer be available.
The Giro Crash Replacement Programme
The Giro Crash Replacement Programme is available only to customers that are resident in the UK and purchased their helmet from a UK dealer. A helmet up to three years old can be replaced at a reduced price, if it has been involved in an accident. The replacement will always be the same model as the original or the nearest current equivalent if the original is no longer available. When the same colour helmet is no longer available, the customer will be offered a choice from the current range.
The official reason is that the polystyrene hardens with time, so it no longer absorbs energy as it collapse on impact.jethro10 said:I read recently, but can't remember where, that a helmet should be replaced every 3 years even if undamaged.
Does anyone know why it becomes, unsafe I guess, after approx. 3 years?
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