Originally Posted by Eddie
I think that when people refer to "start up drag" or "start up inertia" they are really talking about stiction. That is, the slight increase in drag friction as the spool begins to turn. I can feel it in some very fine reels, but in practice, a reel would have to really suck for this to be an issue since we usually fish with drags that are light compaired to the breaking strength of the tippets. I think it is mostly an issue in the shop. For instance, all my Islanders (and every one that I have seen) have had slightly more stiction than my Abels or Tibors (draw bar/cork drags). I've never noticed a problem while fishing.
Yes. Static friction (stiction is not a word despite what you'll find on the web that may be changing though as it is used more) is what people are incorrectly calling "startup inertia".
You have it backwards about the friction on the drag surface for the moving versdus stationary spool though. There is a decrease
in friction when the spool begines to turn -not an increase. Static friction always exceeds dynamic friction. If you look up a table of coefficients of friction for various material in contact with other materials, you'll see that the dynamic friction coefficients are less. With a good drag, the static friction will be close to the dynamic friction and as a result the lines comes out smoothly.
With a bad or poorly-maintained drag, the static friction is so great that a relatively large amount of torque (leading to friction on the drag surface) is required to cause the spool to begin turning which is followed by the spool spinning rapidly and then stopping and restarting again. You'll see the rod actually throb as the spool starts then stops then starts, etc, repeatedly.