Originally Posted by
nlerner
From a 1970s "Raleigh Bicycle Owner's Manual" on lubricating Sturmey-Archer hubs:
"The ideal rule for lubrication should be two or three drops of oil every month, which will maintain the hub in first class running order. USE ONLY STURMEY-ARCHER OIL (OR SAE 20 GRADE). DO NOT use thick oil or grease."
Neal
Gear oil is thick oil. Although, the big drawback is probabaly just some extra drag.