You're taking that out of context. In the book "Ride hard Ride Smart Ultimate street strategies for advanced motorcyclists" by Pat Hahn, the statistics show that riders between the age of 16 and 24 are significantly overrepresented. Those were the buyers of those performance motorcycles and were not always ATGATT. Inexperience was more the root cause.
You're right about HD riders being overrepresented, but that has more to do with experience. First time buyers who are older and have the means typically are in this group. But on the whole, riders between 30 - 50 are significantly underrepresented in crash stats. As are large displacement motorcycles, the flip side of that is, when larger motorcyles are involved in a crash, they are associated with higher injury severity.
Other interesting stats from that book:
Riders with dirt bike experience are significantly underrepresented in accident data.
Helmeted riders are underrepresented in crash data.
(He quoted this from the Hurt study) 90 percent of all crashes happened within the first hour of riding and a whopping 50 percent happen within the first six minutes.
So much for being "safe" to just run an errand. Their conclusion was due to the rider's attention not being on riding but rather where they were going. The time it takes to put on gear, i.e. helmet, gloves, etc, often times made the difference in changing the riders mindset to focus on riding not the destination.
Ride Hard and Ride Smart, First of 4 books that Mr. Hahn has published, came out in May of 04. I got this info from Amazon, but I have copies of all of Mr. Hahn's books.
I can't be sure but I believe that you may be mis-quoting Mr. Hahn, and you are definately mis-quoting my data. First off... I was specific about the data that looked at type of motorcycle involved was limited to California and Oklahoma, not national. I know that Mr. Hahn's data was from NHTSA and this was national data and it was age specific on riders. Since Mr. Hahn's book came out in 04 and he was using NHTSA data, it is a safe presumption that his data was from 2000-2001 because this is the time span for NHTSA data from around the book release date.
California was the first state to actually look at motorcycle type specific data. They released the first report in 2011 and did and update in 2012. Oklahoma was the next state where this occurred. NHTSA data has never been type of motorcycle specific. So, if Mr. Hahn did say "the statistics show that riders between the age of 16 and 24 are significantly overrepresented. Those were the buyers of those performance motorcycles and were not always ATGATT. Inexperience was more the root cause." He was making the presumption that this age group was buyng performance motorcycles. Because the simple fact of the matter is that at the time the book was released there was no specific data about what age group was riding what bike.
One caveat to this, Mr. Hahn may have got some data from the Motorcycle Industry Council which is the group that represents motorcycle manufacturers and tracks motorcycle sales. At the time Mr. Hahn's book was released the MIC may have had some data about what age was buying what bike. However, if he used this data I am pretty sure he would have referenced it in the book and I don't remember that.
As for the following;
"You're right about HD riders being overrepresented, but that has more to do with experience. First time buyers who are older and have the means typically are in this group. But on the whole, riders between 30 - 50 are significantly underrepresented in crash stats. As are large displacement motorcycles, the flip side of that is, when larger motorcyles are involved in a crash, they are associated with higher injury severity."
I am a little confused on a few things in this statement. Up until about 2011 the age group of 34-55 was the fasting growing age group of riders involved in fatal crashes... according to NHTSA data from about 2001 through 2011. They may have been underrepresented at some point over this time span, but toward the end no. NHTSA's postion for this was kind of what I think you are trying to say, the new rider was the baby boomer coming back into the riding market. NHTSA was trying to say that this rider was not use to the larger displacement motorcycles and this was why they were crashing.
There were a few people at NHTSA, me being one of them, who did not buy this because we had no data showing how many motorcycles were being purchased by the age group. And, both the Hurt Report and the MAIDs report the Hurt Report for Europe, do show that more experienced riders are less likely to be involved in crashes.
As for higher displacement motorcycles being involved in higher injury crashes.... I would like to see a source for this because this is the first time I have heard of any data like this. I am particularly interested to see what is defined as a higher displacement motorcycle.
The only thing I have seen so far that are kind of close to this were two different helmet studies out of Japan that in essence said crash at 50 Kmh (37 mph????) and you will die no matter what.... not supported conclusions, but stated nonetheless. And these reports were not displacement specific.