I think that 30 weight NON-Detergent motor oil is the absolute best thing to use in a Sturmey-Archer hub...it does not have detergents and additives in it that most motor oils do that will cause the parts to gum up over a period of years. It is a little difficult to find in some places, but I find it locally at Ace Hardware stores and Auto Zone. While those detergents and additives are a must for high rpm engines, they can really cause small gears and pawls to gum up in a three speed hub.