moshe_levy Posted September 5, 2017 Share Posted September 5, 2017 All- I'm going to get a bit more scientific than usual in this new video, as we delve into the subject of Ultraviolet Radiation's effect on our riding gear and on our health. It's a subject that doesn't get nearly as much attention as it should! Tune in for objective Ultraviolet Protection Factor and Accelerated UV Aging tests on leading products from Aerostich, BMW, and Scorpion. -MKL Link to comment
Green RT Posted September 5, 2017 Share Posted September 5, 2017 I would also be interested in knowing what UV exposure does to helmets. Do they degrade over time. Probably yes, but how much. When to they need to be replaced. There is a fair amount of discussion of this on Motorcycle forums, but I found little hard data. In particular, I am curious about the effect of UV on the shell, rather than the effect of sweat and time on the lining. Damage to the padding seems more obvious. It compacts and can get crumbly. But damage to the shell from UV would be less visible. Link to comment
fastlarry Posted September 5, 2017 Share Posted September 5, 2017 will helmet visors pass UVA radiation? Link to comment
moshe_levy Posted September 5, 2017 Author Share Posted September 5, 2017 My helmets (currently Shoei and Arai) both say that the visors block 99.9% of UV. So I take that to mean that they basically block UV like a good set of sunglasses do. -MKL Link to comment
Joe Frickin' Friday Posted September 13, 2017 Share Posted September 13, 2017 will helmet visors pass UVA radiation? These are usually polycarbonate, which means two things: 1) Polycarbonate itself does not transmit UV. 2) Polycarbonate is damaged by UV, so polycarbonate items designed for outdoor use typically comes with a UV-protective coating (I'm now wondering whether the yellowing/frosting on the outer surface of plastic headlight lenses happens over time as the protective coating is eroded by tens of thousands of miles of sandblasting, leaving bare polycarbonate to be attacked by UV). So your eyeballs are very well-protected behind UV-proof polycarbonate and a layer of UV-proof coating on top of that polycarbonate. I would also be interested in knowing what UV exposure does to helmets. Do they degrade over time. Probably yes, but how much. When to they need to be replaced. There is a fair amount of discussion of this on Motorcycle forums, but I found little hard data. In particular, I am curious about the effect of UV on the shell, rather than the effect of sweat and time on the lining. Damage to the padding seems more obvious. It compacts and can get crumbly. But damage to the shell from UV would be less visible. I will speculate that a motorcycle helmet's structural integrity is not significantly affected by ambient UV exposure. Shoei's shell construction process, for example, starts with a molded fiberglass shell, which is then covered with paint and/or graphics. It seems to me you'd have to remove all of that paint/graphics before UV could even begin to attack the structural shell. Link to comment
Green RT Posted September 14, 2017 Share Posted September 14, 2017 So I can stop worrying about whether my 20 year old helmet still works. Thanks. Link to comment
Joe Frickin' Friday Posted September 14, 2017 Share Posted September 14, 2017 So I can stop worrying about whether my 20 year old helmet still works. Thanks. At least as regards the shell and UV damage; I doubt that a helmet that racks up 100,000 miles of use over five years in sunny southern California sustains more UV damage than one with just 10,000 miles of use over the same time period in, say, Scotland. But in my experience, helmets inevitably get dropped and bumped, which can damage the shell and compromise the Styrofoam liner's ability to protect against future impacts. The chin strap and its anchor points and at the buckle also may wear/fret, and exposure to skin secretions and atmospheric oxygen may compromise its overall material strength. The standard "replace after five years no matter what" guideline may be overkill (I'm at 9 years on my current helmet), but it seems to me that 20 years is probably pushing it. If nothing else, I would think that safety technology has probably improved significantly during in the past two decades, and by replacing your 20YO helmet, you might provide yourself with an increased margin of safety. Link to comment
beemerman2k Posted September 15, 2017 Share Posted September 15, 2017 Excellent presentation, Moshe! Thanks! Link to comment
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