I'm no expert, and I certainly don't know the sales numbers, but is seems to me like the last 15-20 years saw a huge boom in motorcycling. I swear half the people I know bought a bike. People who have never ridden before. Yamaha, Polaris, Suzuki, Kawasaki, Honda, and HD came up with a host of new models. It was a period that saw the birth of Victory and the resurrection of Indian from the ashes. HD finally had to learn how to build a reliable bike. The Japanese bikes started building real American cruisers. It was difficult to keep up with all the new stuff!!! Then there's the crotch rocket. Sweet Jesus those things were everywhere. There were Motorcycle TV shows galore and racks full of motorcycle magazines. All kinds of bike groups were formed, even church riding groups in even the smallest towns. Then the craziness began to subside. Was it because of wimpy millennials, the economy, poor marketing or product development, iPhones? I don't know. I think a lot of people just got it out of their system and moved on. Now the market is returning back to pre-boom numbers, and some of the manufacturers are getting caught with their pants down after a couple decades of build-up. My wife and I rode for a number of years, but decided to give it up when we started having kids. We'll ride again someday, but for now, we are into things we can do as a family, like airplanes and boats...