Motorcycle engines create vibrations that are transmitted through the handlebars,
footpegs, and seat into the body of the rider.   The human body doesn't prefer this;
in nature this kind of shaking doesn't exist.   The rider's body may be able to handle
the vibrating for a limited period of time, if the rider is in a good health.
At the same time, nobody's body is congruent (harmonious) with riding on a bike
for hours on end.   When the body is forced to do something it is not congruent
(harmonious) with, there are health consequences sooner or later.

The most reliable way to tell for how long, and how often, your body is
willing to put up with your motorcycle vibrations, is to visit a doctor
trained in NET (Neuro-Emotional Technique).   Through NET your body can tell you
reliably.   Even if it would be necessary to travel a long distance to such a doctor,
it is very worth it.   Good health is priceless.

You may think your bike doesn't vibrate much, but the mind gets accustomed to,
and filters out, what is obvious and unwelcome to the body.
Even small engines can produces strong (enough) vibrations.

To find an NET practitioner, you can follow this link to netmindbody.com,
and then click on the "Practitioner Finder" link.

Note:   A reasonably good sign of how your body is able to handle
bike-riding is how often you visit a chiropractor:   infrequent, or even
non-existent chiropractic adjustments almost certainly equals very little
to no tolerance for motorcycle riding.   Again, NET is the most reliable though.