This got me wondering about what would degrade over time and why. All I could think of is the EPS foam (most of the helmet), the outside shell (usually thermoformed PET or polyethylene terephthalate) and adhesive or tape that binds them together. I've seen the shell separate from taped helmets. PET is pretty durable but it is susceptible to UV. EPS is pretty inert and durable over time as well, usually susceptible to only UV and hydrocarbons (http://buildblock.com/asked-answered-what-is-the-expected-lifetime-of-the-expanded-polystyrene-eps-foam/). All that considered, I would assume that they would degrade slightly over time the more time it spends outside in the sun. Looking around for a video I once saw where they used a 5-axis CNC for milling out the vent holes on helmets I found this which I thought was mildly entertaining: https://www.youtube.com/watch?v=V7WSxzbNDiE It did get me wondering how they make those MIPS helmets, though
Now if I could just figure out how to clean those grungy straps! John On Monday, September 12, 2016 at 1:23:34 PM UTC-7, Daniel D. wrote: > > Only test I've seen on the subject of replacing your helmet due to age not > impact. > > http://www.helmets.org/helmetlineraging.htm > http://www.meaforensic.com/helmet-testing-research > > On Monday, September 12, 2016 at 8:19:15 AM UTC-7, Bill in Roswell GA > wrote: >> >> >> It is highly recommended by several safety organizations that your poly >> foam helmet be replaced every 5 years due to foam degradation. Previously >> they said 7 years. I split the difference and retire a helmet after 6 >> years. >> >> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
