Motorcycle engine oils
Motorcycle engine oils is defined as “a liquid that reduces friction and wear between moving parts within an engine and also serves as a coolant.” To that I’d add that it also functions as an internal housekeeper, collecting and holding debris until it can be deposited in the oil filter, and that it entrains and neutralizes acids and moisture created by combustion.
Lastly, it offers protection against oxidation, especially when the engine sits for an extended period. That’s a lot to ask of eons-old compost, but if it weren’t for Motorcycle engine oils, internal combustion as we know it simply wouldn’t exist.
Lubrication occurs when a thin film of fluid (in this case oil) is inserted between two solid surfaces that move in relation to each other. The film is usually no more than a few hundred microns thick (human hair is between 50 and 150 microns in diameter), and under great pressure.
To some degree, all liquids can act as lubricants, including water, and in fact water can be pretty slippery, as anyone that’s ridden a powerful bike on a wet road knows all too well. But that doesn’t mean water would make a particularly good engine lube, in large part because it lacks viscosity.
Viscosity is defined as a liquid’s ability to resist motion or flow. Water has very low viscosity; molasses, very high. A fluid with higher viscosity creates a thicker film between parts and bears more pressure than a fluid with a low one, so in general it’s better able to withstand pressure, though too thick a film can induce power-robbing friction.
Motorcycle engine oils is thick enough to create a strong protective film, yet not so viscous that it creates a lot of friction between the parts, which makes it an ideal engine lubricant.
