Motorcycle Radiators & Hardware

The times when the majority of motorcycles were air cooled have passed a long time ago. Nowadays, most bikes that you see passing by both on road and off road are liquid cooled. These motorcycles come equipped with a coolant tank, water pump and, of course, a radiator, just like a car or a truck. The latter is one of the most crucial components of your motorcycle’s cooling system since it actually transfers heat from the engine’s coolant to the atmosphere. A radiator is usually located in the front of a bike just behind the front fork.

In and of itself, a motorcycle radiator is a heat exchanger whose job is to take heat from hot coolant and transfer it to the air. The coolant that absorbs heat from the motor is circulated through the radiator pipes, running from the inlet to the outlet. While the coolant is flowing through the radiator, the heat is conducted by dozens of fins brazed to the pipes and then transferred to the outside through the fins. Since air is always cooler than the coolant, heat exchange is effectively performed.

To ensure quick and efficient heat exchange a radiator should be relatively large, which in turn can lead to the increased weight of your vehicle and, therefore, may reduce its performance and fuel efficiency. For this reason, most motorcycle radiators are made from aluminum alloys which are very lightweight as well as perfectly absorb and emit heat. In addition, such materials are very resistant to corrosion, preventing scale and rust buildup inside the tubes, which may obstruct proper coolant flow, and significantly increase pressure in the cooling system and thus damage the radiator, water pump or hoses.

The most common radiator failure is a leak. When you ride, the radiator is subject to flying rocks and debris that may damage not only its delicate fins but also its pipes. Besides, road salt and the elements can erode the aluminum alloy your radiator is made from and cause a leak. Together with exterior hazards, there are some other factors that may lead to radiator failure. One of them is corrosion caused by the use of low-quality coolant or its untimely replacement. Another factor is a failure of other cooling system components like the pump or thermostat.

The pressure in the cooling system of your motorcycle and the temperature of the coolant circulating inside the system are interdependent. When your engine performs at high RPMs, the coolant can get very hot which in turn may significantly increase the pressure inside the system. To keep it under control, many motorcycle radiators are equipped with a pressure cap which does not allow too high pressure to form and thus protects the radiator from damage. The cap comes equipped with a special spring that is lifted up once the pressure reaches around 15psi and then acts as a valve, releasing the excessive pressure.