Anyway the passage tells you a simple way to check to see if your suspension preload is in the right spot...
If your cruiser or tourer has limited leanover clearance, you'll need to be a little
more clever about turns. The giveaway is that your machine makes grinding sounds
and leaves trails of sparks in every sharp curve.
First off, when you get back from a sparkly
ride, check your suspension. Ideally, your suspension
should be in the middle of its travel with
the bike loaded as you normally ride. The best
way to check suspension travel is to sit on the
loaded bike and have someone else do some
measurements. If you normally carry a passenger,
get the passenger on board, too.
If you discover that your machine sits too low
when loaded, first jack up the shock springs to
maxinuum preload, and if that doesn't do it, figure
on replacing the springs with stronger ones.
Sagging front fork springs may be acceptable with
spacers to increase the preload. If your suspension
has air, carefully add a bit of pressure. Adjusting
suspension toward the middle of its travel not
only increases leanover clearance but also helps
keep the tires in contact with the pavement.