What is the reason why the rear brake of a scooter cannot hold?

Question

FelicityDella · Accepted Answer

If it is a drum brake, it may be due to excessive wear of the brake drum or insufficient contact area between the new brake shoe and the brake drum. In this case, the brake shoe needs to be scraped and filed to remove the excess protruding parts in the middle, similar to the process of fitting new shoes to drums in large vehicles, to maximize the contact area between the brake shoe and the drum. Below is some relevant information: 1. Brakes: Brakes are mechanical devices used to slow down or stop a vehicle, also known as decelerators. Scooters generally use drum brakes, which are crucial and must be kept in good condition. 2. Types of brakes: Manual car brakes are located next to the gear shift and are connected to the brake lever. Common types also include bicycle brakes, which rely on rod-shaped brakes fixed to the frame or disc brakes to slow down the vehicle.

BlakelyRose · Answer

In my years of repairing vehicles, scooter rear brake failures are incredibly common. First, check the brake pads—if they're worn flat, it's time to replace them; without friction, they obviously won't stop the bike. Second, the issue could be with the brake cable—over time, the inner wire can seize up, making it very hard to squeeze, or even impossible to pull. Third, water or oil getting into the brake drum is another culprit, especially after rainy days—you'll need to disassemble and dry it out. There’s also an adjustment screw near the rear wheel that’s crucial—if it’s loose, it increases the brake travel, making the brake feel spongy. It’s best to check your bike’s condition every month, especially wear-prone parts like the brake cable. I’ve seen too many people wait until the brakes completely fail before coming in for repairs—that’s way too dangerous.

OSara · Answer

A couple of days ago, my own scooter also had issues with the rear brake not working well. When I took it to the repair shop, the mechanic said the brake shoe was completely worn out. Actually, the lifespan of brake pads is closely related to riding habits—frequent carrying of passengers or sudden braking can accelerate wear. Another unexpected discovery was that the brake cable connector was rusted solid; riding in the rain without maintenance can cause it to rust into a lump. The mechanic taught me a trick: during regular maintenance, drip a few drops of engine oil into the brake cable housing, which can prevent rust for up to six months. Now, before heading out, I always squeeze the brake a few times to test the feel. If it feels softer than usual, I immediately adjust the screws. Safety is something you really can't afford to be careless about.

StNova · Answer

There are four main reasons why the rear brake may not be working properly:

Excessive wear of the brake pads is the primary issue, especially for vehicles used for over two years.
Next, check if the fixing screws are loose—adjusting them can solve the problem.
Then, inspect whether the brake cable is functioning smoothly; any stiffness is a sign of rust.
Finally, check the brake drum for oil stains or water marks, and simply wipe it clean with a cloth.

If you're doing it yourself, replacing the brake pads is the most cost-effective solution, with materials costing just around twenty bucks. However, if you're not familiar with mechanical structures, it's recommended to seek professional inspection and repair—safety is always the top priority.

StMarley · Answer

As a daily commuter rider, I have plenty of experience with rear brake issues. First, rule out brake cable aging—especially bikes frequently exposed to rain are prone to rust seizing. Then remember to check the adjustment nut located below the right handlebar; tightening it inward half a turn can immediately improve braking feel. The most troublesome issue is brake drum oil leakage—last time during repairs, I found the axle oil seal had ruptured. I recommend monthly disassembly to clean brake dust while checking the oil seal condition. During rainy seasons, avoid riding through puddles—my commuter bike once ruined a whole set of brake pads because of this. These small habits can significantly extend your braking system's lifespan.

DelMadelyn · Answer

Brake failure is mainly categorized into mechanical faults and daily wear. The most common wear issue is worn-out brake pads, especially on the rear wheel of scooters which bears more weight. Mechanical problems include stuck brake cables, oil stains or deformation in the brake drum. A self-check can be done in three steps: first, check the thickness of the brake pads, which should normally be 5mm; then, pull the brake lever to see if it rebounds smoothly; finally, spin the rear wheel to listen for any abnormal friction noises. For regular maintenance, it's recommended to clean brake drum dust quarterly and replace brake cables annually to basically avoid the embarrassment of mid-journey failure.