This is what I term "a small subset of crashes".
Realistically, cyclists ride faster than this. And realistically, the types of collisions you want to protect against are not between you and the ground but rather you and a moving object, such as a car. Bike helmets are not rated for these kinds of crashes.
I would not use the Hovding either. The reason I presented it is because it represents a radically redesigned bike helmet.
Anyhow, as I said before, the only thing you can wear to really prevent bad bike accidents is a motorcycle helmet, which are in fact rated for high speed collisions.
I have never seen any reference to bike helmets being "rated" for a specific speed or type of impact. Bike helmets are approved based on a single test carried out by the CSPC which is not calibrated to correspond to any particular speed or type of impact. I don't consider the method of testing helmets particularly important to the well-supported fact that these helmets significantly reduce the risk of serious head injury and death.
There are no well-supported "facts" that helmets reduce serious head injury. In fact, among the cycling community, it is a very hot point of contention.
> A 2012 re-analysis of the 16 studies in the Attewell meta-analysis, by Elvik, found that, compared to helmeted cyclists, unhelmeted cyclists were 2.5 times more likely to sustain a brain injury; 2.3 times more likely to sustain a head injury; and 4.3 times more likely to sustain a fatal injury.
https://en.wikipedia.org/wiki/Bicycle_helmet#Science:_measur...
http://www.drianwalker.com/overtaking/
A Google search will reveal other similar studies as well. Wikipedia is not comprehensive.
Bike helmets reduce the risk of injury in virtually all crashes that an improved helmet would reduce it. They simply don't reduce it as much as an improved helmet would. I don't stress too much about biking with a conventional helmet. Mine is a few years old and I'd like to replace it with a MIPS helmet when they are available, but as it is with a conventional bike helmet, my concerns with biking are:
1. Getting run over by a bus, in which case the helmet is quite moot.
2. Crashing and hurting myself, which with a helmet is unlikely to kill me, but may result in trying to stuff my bike in the back of my wife's car while dripping blood.
The Hovding is something I would never in a million years wear. I want protection from tree branches and similar, and I don't want to worry about throwing out a $300 single use item after a minor spill.