A $5 rubber strap wrench from sears (or wherever) makes it easy to
turn the cap... if the cap is all-the-way loose, you can't see any of the
threads it turns on. As you crank it down, you start seeing more and more
of the threads it turns on. I call it good when it seems like the same amount
of threads are showing on each side. If you bottom out over every bridge
expansion joint, you need to crank it down more. If you never-ever-never
bottom out even on the most gnarly hit, you're not using all your travel.
Spending all day blasting over gnarly pot-holes searching for where it
bottoms out is probably ill-advised

...
-Mike