What is the principle of the motorcycle CBS brake system

Update:23 Sep, 2020
Summary:CBS is the abbreviation for front and rear linkage brake system, and its full name is Combination Br...

CBS is the abbreviation for front and rear linkage brake system, and its full name is Combination Braking System.

So why can CBS significantly shorten the braking distance? To put it simply, the configuration of CBS is that when the rider applies the brake, the front wheel brake or the rear wheel brake is operated alone, and both wheels of the motorcycle can be effectively braked.

Under normal circumstances, when riding or accelerating, the rear wheels carry most of the weight of the motorcycle, and the friction obtained is greater than that of the front wheels. However, when braking, due to inertia, the center of gravity of the motorcycle will shift to the front wheels.

Therefore, when driving a motorcycle, the rider should first apply part of the braking force to the rear wheels so that the center of gravity of the motorcycle can be quickly transferred to the front wheels, and then apply most of the braking force to the front wheels according to the choice of the first seven and the third. A wide range of braking methods.

But in the actual driving process, especially in the case of emergency braking, there is no time to allow you to follow the steps step by step. According to calculations, when a motorcycle is taking the above braking measures at a speed of 80KM/H, It takes 0.5 seconds to complete all the steps. According to this speed, it can travel about 11.1 meters in 0.5 seconds, and the danger is always close to a thousand miles away.



But when the CBS device is activated, you only need to deeply step on the rear brake lever (left brake lever). At this time, the CBS linkage device will first apply a part of the braking force to the rear wheels (note that it is only part), causing the motorcycle's center of gravity to shift to the front wheels, and the friction will increase. At this time, when you continue to increase the braking force, the front wheels will be able to To obtain the ideal deceleration effect, this method is simpler, more efficient and more accurate than manual braking force distribution, so the braking distance can be significantly shortened. According to calculations, under normal circumstances, it only takes 0.2 seconds for the motorcycle to produce a braking effect. It can produce braking effect 6.66 meters earlier than models without CBS braking device, which makes the response time faster and the braking distance shortened.

So does it mean that motorcycle brakes mainly rely on the rear wheels? In fact, it is not. This just shows the reason that the front wheel is the main source of braking force. This is not contrary to the principle that motorcycle braking mainly relies on the front wheel. The reason is that CBS only simulates braking when artificially applying part of the braking force first. At the rear wheels, the center of gravity is moved forward, the front wheels get greater downforce and the friction is increased, and the braking force of the front wheels superior to the rear wheels is fully released, and that's it.

What we commonly use is the rear wheel combined braking, that is, the braking force applied to the rear wheel brake pedal (straddle) or the left rear brake lever (pedal) alone can simultaneously brake the front and rear wheels.

So how do you know if the motorcycle has a CBS configuration? The method is very simple. Since most CBS control the front and rear braking force through the rear brake, you only need to prop up the motorcycle with a big brace to make the front wheel off the ground, turn the front wheel by hand to make it rotate freely, and then quickly tighten the rear. Brake lever, if the front wheel immediately stops rotating at this time, then it can be concluded that the CBS is configured.

Or you can observe the front brake system. Generally, motorcycles without CBS have only one brake hose on the front wheel (except for double discs). If two brake hoses are connected to the caliper, it can also prove to be equipped with a CBS front and rear linkage brake system. .

The front and rear linkage braking system of CBS is currently a mandatory configuration of the European Union. The European Union sells motorcycles in the country with a displacement equal to or less than 125CC, a power less than or equal to 11KW, and a thrust-to-weight ratio less than or equal to 0.1KW/KG. The safety configuration of CBS is A mandatory requirement that any brand of motorcycle must meet this mandatory requirement before it can be sold in the European market.