To prevent all that ugly stuff from happening, we wear helmets. Modern, full-face helmets, if we have enough brains to protect, that is.(....)
First, about half of all serious motorcycle accidents happen when a car pulls in front of a bike in traffic. These accidents typically happen at very low speeds, with a typical impact velocity, after all the braking and skidding, below 25 mph.(...)
The next-biggest group of typical accidents happens at night, often on a weekend, at higher speeds. They are much more likely to involve alcohol, and often take place when a rider goes off the road alone. These two groups of accidents account for almost 75 percent of all serious crashes. So the accident we are most afraid of, and the one we tend to buy our helmets for?crashing at high speeds, out sport riding?is relatively rare.
Even though many motorcycles were capable of running the quarter-mile in 11 seconds (or less) and topping 140 mph back in '81, not one of the 900-odd accidents investigated in the Hurt study involved a speed over 100 mph. The "one in a thousand" speed seen in the Hurt Report was 86 mph, meaning only one of the accidents seen in the 900-crash study occurred at or above that speed. And the COST 327 study, done recently in the land of the autobahn, contained very few crashes over 120 kph, or 75 mph. The big lesson here is this: It's a mistake to assume that going really fast causes a significant number of accidents just because a motorcycle can go really fast.
Another eye-opener: In spite of what one might assume, the speed at which an accident starts does not necessarily correlate to the impact the head?or helmet?will have to absorb in a crash. That is, according to the Hurt Report and the similar Thailand study, going faster when you fall off does not typically result in your helmet taking a harder hit.