There's a chapter in Lean on Me that includes riding motorcycles. I won't go into any more detail.
In the story, instruction is very abbreviated. That's for the sake of the story. In truth, much more time was spent on learning and practicing. There are 5 factors that contribute to the majority of accidents or deaths.
Drivers turning left in front of motorcycles
Alcohol consumption
Poor weather
Night
Riding beyond your experience or capability
In the story, none of those conditions existed. It was a perfect day. I just wanted to put this out so people won't think I'm encouraging anyone to hop on a motorcycle and go for it.
Riding motorcycles is inherently dangerous. However horseback riding is, statistically, more dangerous. Proper gear reduces the danger level for both. For bikers, the crazy drivers in the other lane are a huge factor. For equestrians, the temperament of the horse is a huge factor.
I haven't ridden a motorcycle in 5 years but I continue to ride horses. Either way, I'm always careful.