Can the rear wheels lock up and cause skidding or fishtailing during braking?

[DeWalker]

Braking with the rear wheels locked up can indeed cause skidding or fishtailing. Here are the relevant explanations: 1. Skidding: Skidding refers to the phenomenon where a vehicle experiences a lateral swinging motion due to sudden acceleration, abrupt braking, or excessive torque during startup, commonly known as fishtailing. There are many factors that can cause a vehicle to skid. Driving on snow, rain, or ice and suddenly releasing the throttle or accelerating abruptly; applying emergency braking where the rear wheels lock up before the front wheels; all these scenarios can easily lead to vehicle skidding and result in accidents. 2. Lateral Disturbance Force: If the rear wheels lock up, while the rear wheels are subjected to a lateral disturbance force, the front wheels will have a self-aligning torque effect. This creates two horizontal forces acting in opposite directions at the front and rear of the vehicle, forming a torque that can quickly cause the vehicle to fishtail or skid.

[LaEllie]

I remember when I was driving an old car and braked too hard, the rear wheels locked up completely, causing the car to suddenly fishtail and spin, nearly causing an accident. After that incident, I looked into it and learned that if the rear wheels lock during braking, they lose their ability to rotate and simply slide on the road surface, leading to a loss of traction control—especially dangerous in corners or on wet roads. This is related to weight transfer: during braking, the vehicle's center of gravity shifts forward, reducing the rear wheels' grip and making them more prone to sliding. That's why it's important to avoid slamming on the brakes abruptly and instead practice gentle braking or rely on the ABS system. Regular checks on brake pads and tire tread patterns are also crucial—prevention is better than cure.

[Jayla]

When the rear wheels lock up during braking, it will definitely cause the car to skid and fishtail. I've analyzed it from a physics perspective: once the wheels lock up and slide statically, they lose rolling friction, and the steering force weakens, making the rear of the car prone to drifting out of control. It feels similar to pulling the handbrake to drift, but it's very dangerous under normal braking. Modern vehicles are equipped with ABS technology, which can release brake pressure when it detects wheel lock-up, keeping the wheels turning and preventing fishtailing. Developing the habit of braking smoothly and slowing down in rainy weather can reduce the risk. Pay attention to vehicle maintenance—don't wait until an accident happens to address issues.

[DelBrandon]

Rear wheel lock-up braking can indeed cause skidding and fishtailing, which is a hazard I always pay attention to while driving. If you brake too hard, causing the rear wheels to stop rotating and slide, steering becomes difficult to control, especially on slippery roads or high-speed curves, where the rear of the car may suddenly swing out. The preventive measure is to avoid slamming the brakes; gently tapping them a few times is safer. If the car is equipped with ABS, it will automatically adjust. It's advisable to regularly test the braking performance and fix any issues promptly, as this concerns the safety of both yourself and others.

[GarrettAnn]

Compared to front-wheel lock-up and braking issues, rear-wheel lock-up is more prone to causing skidding: front-wheel lock-up may lead to understeer, but rear-wheel lock-up directly results in rear-wheel sliding and loss of control, causing side skidding. The ABS system is designed to address this, as it can regulate the brake calipers to prevent lock-up. I personally experienced this danger when driving an old car without ABS—the car spun around, which was quite terrifying. The solution is to upgrade the braking system or practice the technique of pumping the brakes. Don’t overlook this risk, as it often occurs when brake pads are worn or tires are old.