EDIT: Don’t bother reporting people criticizing others for not wearing a helmet. It’s not victim blaming, just like criticizing someone for not wearing a seatbelt isn’t victim blaming.
Wear your helmets people: Of course nobody deserves to get hit by a car but the reality is people are getting hit by cars.
Speed does not – in and of itself – somehow create more collisions. What makes a collision is a difference of relative speed.
From my list earlier, absolute speed would tend to exacerbate scenarios 1, 2, 4, and 6. But would make little difference to scenario 3, and scenario 5 would depend on the speeds of other bicyclists. My analysis points out that if scenario 3 is what has been drastically increasing in the past decade – which is corroborated by the Oregon study linked earlier – then no, speed is pretty much irrelevant. Being struck by a motor vehicle driver making a turn is going to be bad, no matter what speed the bicycle, ebike, or motorcycle was going.
What I cannot show – nor can anyone show otherwise – is the prevalence of those scenarios in proportion to overall collisions. We simply have insufficient data, which should be a call to action for better information from collision investigations.
But again, just because helmets are not useful in one situation does not mean that they are worthless in all. They are very helpful in a subset of situations and should be worn for those situations.
Who was arguing that helmets are worthless? I don’t see that thread.
You might be missing practical experience of falling off a bike. Happened to me. Speed makes a difference in any situation where the bike falls over or the rider falls off the bike. why? because speed is a major source of kinetic energy when colliding with the ground (the other source is the difference in height). You listed 6 different possible causes for falling off a bike, and all of them result in more energetic falls if the bike is going fast.
Are we concerned about an initial impact, the probable falling-off that occurs afterwards, or both? I personally care mostly about the reasons for initial impacts because without colliding with anything, falling off a bike becomes much less frequent and less severe.
Even the circumstance of falling off a bike without a collision with anything else is improved for everyone by good infrastructure: grass-lined paths, telephone poles placed far away, a buffer between oncoming bike path lanes, full separatiom from cars, etc… All those infrastructure changes benefit everyone, irrespective of whether a particular rider falls while wearing a helmet or not.
This fixation on helmets is a case of missing the forest for the trees.
if you change the perspective like that, yeah, safer bike infrastructure is very important.