Why Do Scooters Shake at Low Speeds?
3 Answers
Here is a detailed explanation of the reasons why scooters shake at low speeds: 1. The primary reason is the long-term dynamic friction between the shoes of the rear clutch plate and the housing in the belt box. 2. Reduced friction between the shoes and the housing: The surface of the shoes becomes contaminated with friction-generated powder or dust from the air intake at the front of the belt box, leading to decreased friction between the shoes and the housing. This causes slipping, resulting in the sensation of shaking during startup or at low speeds. 3. High load during startup: The load during startup is significantly greater than that at high speeds. As anyone who has studied physics knows, the maximum static friction of an object is greater than its maximum kinetic friction. 4. For smooth operation, the shoes and the housing need to be in tight contact, or the friction coefficient must be increased. This is why some housings have a sandblasted finish or deliberate scratches.
The scooter shakes at low speeds, which might be related to the drivetrain. I've encountered many similar cases, usually due to aging drive belts. Over time, belts loosen, and at low speeds when engine RPM is insufficient, the belt can't move properly and slips, causing severe shaking. Clutch issues are another possibility - if it's significantly worn, engagement at low speeds becomes rough, leading to trembling. These causes of vibration not only make riding uncomfortable but also accelerate wear on other components. I recommend having a professional shop check for belt cracks or wear; replacement typically costs around fifty to a hundred yuan if needed. Regular maintenance and keeping the drivetrain clean can prevent such issues, ensuring smoother rides.
I've been commuting on a scooter for ten years, and low-speed shaking is often caused by tire or suspension issues. For example, uneven tire wear or wheel hub deformation can cause wobbling at low speeds. Loose suspension connection bolts can also make the body unstable. The inspection method is simple: after parking, shake the front and rear wheels to feel for looseness; check if the tire surface is uneven. Unstable idling, such as dirty spark plugs, can also cause shaking. Remember to maintain it promptly to avoid costly repairs when the problem worsens. This is much safer, especially during rush hour—it's much more comfortable when the scooter doesn't shake or wobble.
