What is a Swingarm?
2 Answers
Motorcycle's swingarm, also known as the rear fork, refers to the part that connects the rear wheel to the motorcycle's body. It serves to secure the rear wheel, bear the body's pressure, and maintain stability. Additionally, different types of swingarms can significantly impact the bike's performance. Below are several types of motorcycle swingarms: Round Tube Swingarm: Rarely used in modern vehicles, commonly seen in retro-modified bikes. Square Tube Swingarm: The most widely used and cost-effective, but may not provide sufficient support and stability for heavy-duty motorcycles. Lower Triangular Swingarm: The best design structure for resisting pressure and tensile force in modern times, often used in racing scenarios due to cost considerations. Gull-wing Swingarm: The top choice for versatile road conditions, capable of handling various daily riding situations such as mountain roads, highways, and race tracks, while also being relatively low in manufacturing cost.
The rear swingarm is a critical component of a motorcycle's rear suspension system, connecting the rear wheel to the frame and allowing the wheel to move up and down to absorb road shocks. I've seen it in modified bikes, where common materials include aluminum alloy due to its lightweight and sturdy nature. Structurally, it can be single-sided or double-sided—single-sided arms are easier to maintain, while double-sided arms provide stronger support. This part works in tandem with the shock absorber and directly affects ride stability. If the rear swingarm lacks sufficient rigidity, excessive body lean during cornering can compromise safety. I've tested some bikes where poor design led to noise or vibrations. The rear swingarm is crucial for performance, especially on rough terrain, as it reduces impact sensations. When choosing one, it's essential to balance strength and weight to ensure smooth and efficient riding.
