I subjected five reels to identical ambient-temperature changes and later to fast, 100-yard drag runs. Results were uniform for each reel, but varied markedly from one drag system to the next.
Changes per Ambient Temperature
All reels tested provided less drag as temperatures warmed. When checked at 40 then 65 degrees, all reels lost at least 1½ pounds of drag.
Changes in grease viscosity account for part of that change, says Chris Littau, who oversees development of saltwater Fin-Nor, Van Staal and Quantum reels. He also points to differences in expansion of aluminum, stainless and composite components as the temperature changes. "That's why spinning reels change so much. When that aluminum spool expands it changes pressure on the drag," he says.
Changes per Operating Stress
In lever- or star-drag reels after a 10-mile-per-hour 100-yard run, drag tension had typically increased ¼- to ½-pound three minutes after the run. Years ago, those numbers would have been higher, but Littau says great strides here in the past decade come from advances in drag material and grease, as well as reels designed to better dissipate heat.
Changes per Spool Diameter
Starting at 14 pounds of drag, the two lever-drag reels I checked increased drag by roughly half a pound for every 100 yards of 30-pound mono taken off the spool. This was a little less noticeable for the first 100 yards and more pronounced for the last 100 yards, since the fatter full spool shrinks relatively less for each yard of line pulled away than with the reduced usable diameter of a nearer-empty spool. (See drawing from Fin-Nor.)