What are some tips for dealing with ineffective drum brakes on motorcycles?
2 Answers
There are various reasons for ineffective braking, with common issues such as brake pad problems. You can try sanding the brake pads and brake discs/drums, or replace the brake pads if necessary. Below are the reasons for brake failure: 1. Bent pedal due to a fall or collision: The effective length of the lever arm is shortened, reducing the amplification of braking force. 2. Wear of brake shoes: Worn brake shoes cause excessive rotation of the brake cam, altering the direction of braking force transmission and reducing the lifting effect, which prevents effective transfer of braking force to the brake shoes, further weakening the braking force. 3. Misalignment between brake shoes and the hub: One reason is excessive clearance during assembly, leading to misalignment—for example, the fit clearance between the axle and the brake disc hole, or the spline fit clearance between the GY6125 rear axle and the hub. The second reason is offset of the support pin position. The support pin precisely positions the brake shoes; once offset, it causes misalignment between the brake shoes and the hub, which is more common in three-wheeled vehicles. Corrections can be made based on the actual situation. 4. Low friction coefficient of brake shoes: Braking relies on friction to decelerate, making the friction coefficient crucial.
Once when I was riding my motorcycle, I felt the drum brake wasn't working well. When I pulled the brake lever, there was very little resistance, and the bike wouldn't stop. I quickly pulled over to check and found that the brake shoes were severely worn, almost completely gone. After replacing them with new ones, the braking performance improved immediately. Daily tips include regularly cleaning dust and grease inside the brake drum, wiping with a cloth to avoid clogging; checking the thickness of the brake shoes—replace them if they're below 1.5mm; manually adjusting the brake clearance by tightening the adjustment screw to reduce the gap, and testing if the free travel is within the normal range. For prevention, do a simple check every few hundred kilometers—don't wait until it becomes a safety issue. If you can't handle it yourself, seek help from a reliable repair shop.
