Most motorcycles use air cooling or oil cooling systems to cool their engines instead of relying on a traditional liquid coolant radiator like in cars. Here's an explanation of each cooling method:
Air Cooling: Air-cooled engines have fins on the exterior of the engine cylinders and heads. These fins increase the surface area of the engine, allowing more heat to dissipate into the surrounding air. As the motorcycle moves, air flows naturally over the fins, carrying away heat and keeping the engine cool. This design is common in smaller motorcycles and classic or retro-styled bikes.
Oil Cooling: Some motorcycles, especially those with larger or higher-performance engines, use oil cooling in addition to or instead of air cooling. In an oil cooling system, the engine oil circulates through passages within the engine, absorbing heat from the components. The heated oil then flows to an external oil cooler, which is essentially a small radiator. Air flowing over the oil cooler helps dissipate the heat from the oil, cooling it down before it returns to the engine.
It's worth mentioning that there are a few motorcycles with liquid cooling systems that use radiators similar to cars, especially those with high-performance engines or those designed for touring or sport riding. Liquid-cooled motorcycles typically have a radiator positioned in the front of the bike to facilitate the flow of air and dissipate heat from the coolant.
These cooling methods have been used for many years and continue to be reliable and effective in keeping motorcycle engines within their optimal operating temperatures.