by Robert Sanborn on Thu, Oct 18, 2007, who was a member of the STLE Society of Tribologists and Lubrication Engineers for 15 years.
Chain maintenance whether on a bicycle or motorbike is one of the most controversial subjects between mechanics. The major cause of chain “stretch” is wearing away of the metal where the rivet rotates inside of the bushing (or the “bushing part of the inside plate) as the chain links flex and straighten as the chain goes onto and off of the sprockets. Premature chain fatigue can be a real problem and effect gear shifting and performance.
Three Points of Chain Lubricaton
First one must be aware of the three points where a chain needs lubrication
The rivets need to be lubricated where they move inside the inner links as the chain bends and straightens.
The insides of the rollers need lubrication to let them revolve freely around the bushings as they engage and disengage in the sprocket teeth, which can cause accelerated sprocket wear.
The surface where the outer side plates overlap the inner side plates can benefit from lubrication as well, although this contact surface is much more lightly loaded than the first two.
Thick or Thin?
The problem with lubricating conventional chains is that thick lubricants cannot penetrate into the inaccessible parts where they are really needed, but thin lubricants do not last long enough in most cases. Due to the speed of the chain grease or oils fortified with tackifiers should not be used as they will attract dust and dirt and will only add to the problem of premature wear. Light oils will be thrown off due to the speed of the chain and spalling will take place on the rollers. For high-speed chains there is only one type of lubricant that can be used that will stay on the chain and not attract an inordinate amount of dust and dirt. Such a lubricant must be thin and contain additives called extreme pressure agents. An extreme pressure agent is acidic and thus attaches to the metal and is resident at all times.
Extreme Pressure Agents
Extreme pressure agents can carry loads up to 800 kilograms, which is a tremendous amount of pressure. I found such a product that is absolutely ideal for chains. The product is named ProTecta Precision Needle Oiler, by SFR Corporation, who specializes in extreme pressure technologies. In checking the testing, this product beats the testing parameters of the 4 Ball Extreme Pressure Test ASTM D 2783 as it exceeds the 800 kilogram limit. It comes in a half-ounce container where only a drop is required on each of the rollers. The product almost dries; however, in our bearing test machine the product takes a tremendous load even when what appears to be dry. This product lasts for at least three months and is outstanding for chains. This is a remarkable product for chains as it is a synthetic and will withstand heat as well.