No, it is not true that riding a motorcycle at a constant speed for a long time is inherently bad for the engine. Modern motorcycle engines are designed to handle extended periods of constant speed riding without any significant issues. In fact, many motorcycles are specifically designed for long-distance touring, where riders often maintain a consistent speed for extended periods.
The concern about constant speed riding being harmful to the engine might be based on older motorcycles or outdated information. In the past, some engines required periodic variations in speed to prevent oil starvation and promote proper lubrication. However, modern engines are engineered to provide sufficient lubrication and cooling even during prolonged periods of constant speed riding.
Cruise control is a feature found in some motorcycles that allows riders to maintain a steady speed without continuously holding the throttle open. It is primarily designed for comfort and convenience during long-distance rides, reducing fatigue on the rider's hand and wrist muscles. Properly designed cruise control systems do not cause any harm to the engine when used within the manufacturer's specified limits.
It's important to note that while constant speed riding itself is not detrimental to the engine, it is still essential to follow proper maintenance procedures for your motorcycle. Regular oil changes, air filter cleaning/replacement, and other manufacturer-recommended maintenance practices are crucial for the overall health and longevity of the engine, regardless of the riding style or duration.
So, if your motorcycle is equipped with cruise control and you enjoy riding at a constant speed for long distances, there is generally no need to worry about damaging the engine. Just make sure to adhere to the manufacturer's guidelines for maintenance and servicing.