Why Are Buses So Bouncy?

In this article, we’ll focus the spotlight on answering the question, Why Are Buses So Bouncy? You’re a bus driver and you can’t seem to figure out why your bus bounces; it’s very likely that you’d want to know exactly it happens that way. And, if someone asks you that question, what would come into your mind? In order to ensure you have a valuable response, we have put together this article.

Let’s proceed.

Why Are Buses So Bouncy?

The air suspension stands as the reason why bus bounces or is bumpy. The seats for the other passengers are closer to the suspension simply because the seats aren’t air pressure. On the seats of the bus driver is air pressure, because it’s the bus driver that stays in the bus even longer than the passengers.

What’s An Air Suspension System?

An air suspension system is a variety of vehicle suspension that’s either powered by an electric pump or powered by a compressor that works in pumping air into flexible bellows which are manufactured by a textile-reinforced type of rubber. In addition to the aforesaid, air suspension is described by Pro Car Mechanics as a full replacement to the leaf suspension or coil spring system with airbags composed of rubber and polyurethane.

A compressor performs the job of inflating the bags to a particular pressure in a bid to behave like springs. Air suspension isn’t the same as hydropneumatic suspension. You want to know why? Well, it’s simply because it makes use of pressurized air rather than pressurized liquid.

What’s The Purpose Of An Air Suspension System?

Most of the time, air suspension plays the role of helping you achieve a constant and smooth driving quality, but in just a few cases, air suspension is featured in sports suspensions as well. Similarly, air suspensions serve as a replacement for a conventional steel spring suspension in heavier vehicle applications, such as passenger buses, tractor-trailers, trucks and even passenger trains. Also, air suspension is very common in low-riding trucks — example: the gorgeous 1982 Dodge D200 Camper Special.

What Is Electronically Controlled Air Suspension?

According to a company that has changed its name to Dunlop Systems And Components, at the start period of the 1990s, Dunlop successfully developed and also installed the Electronic Controlled Air Suspension (ECAS) system. It was first installed on the 1993 Range Rover Classic and then, it was installed on the Range Rover P38D. The company, based in the United Kingdom, put together the ECAS to consist of numerous features that include the following:

  • An air compressor in the trunk of the vehicle or right under the vehicle’s hood.
  • Heavy-duty, vulcanized rubber air springs at every one of the wheels of the vehicle.
  • A storage tank meant specifically for compressed air, which allows you to preserve air around an average of 150 PSI.
  • Valve blocks that do great in directing air to the four springs from the storage reservoir through a set of solenoids, valves, and springs.
  • Air pipes that connect from the storage tank to the air spring which channel the flow of air throughout the suspension system.
  • ECAS computer which communicates between the main computer of the vehicle to calculate the area to which air pressure should be directed.
  • A desiccant-filled drier canister used to keep the system’s internal recesses dry.

The electronically controlled air suspension also comes with height sensors that handle the job of sensing resistance that gets in contact with the terrain on all four of the vehicle’s corners to provide something called heigh resistance suitable for all corners. In addition, more advancements are starting to introduce some Electronic Control Units (ECUs) that can fit perfectly under the floorboard of the vehicle, making air suspension more widely featured in everyday driving.

Basic Advantages Of Air Suspension For Buses

Modern buses come with either a mechanical suspension system or an air suspension system. Air suspension uses “air springs.” Another name given to the air springs is “bellows,” and with the help of an engine-driven compressor, they’re filled with air. What determines the spring rate and ride height is the amount of air that the bellows contain. You might want to ask, “what gives air suspension significant advantages over mechanical suspension systems?” Well, the answer to that question is “its adjustability.” Its adjustability, to a large extent, allows the makes of the air suspension system to maintain ride height, irrespective of the load.

Furthermore, you achieve this by carrying out the process of varying the bellows’ pressure. An incredible thing about the ride height is, it has the potential that allows anyone to raise it above the normal height in order to provide enough clearance whenever you start taking steep ramps. To bring ease for passengers when it comes to getting aboard, it can as well be lowered.

To achieve comfort and utmost performance, the most important factor is the adjustability of the air suspension system. It provides a consistent and smooth ride quality. Passengers can arrive at their destination fresher. It also helps in the reduction of driver fatigue, which is great for road safety and for the driver’s health. After all, a driver who’s less tired can have more focus.

This air suspension has been in existence for more than a century. However, air springs have evolved to become viable springs suitable for buses and every other large vehicle out there in the previous two decades. In those years, the air suspension was recorded to be less durable, compared to the conventional suspension. This is simply the bellows’ nature, and they are manufactured using reinforced rubber. The upkeep which it required was more, and it had high chances of being the cause of problems on the road. It wasn’t durable and reliable until stronger bellow materials were introduced and developed that the air suspension has transitioned into being a standard in modern buses.

Types Of Buses

Coach / Motor Coach

This is a bus used to transport people going to long distances and are concerned about utmost comfort. In other words, transporting in this bus, that has more room, assures you of utmost comfort. It has just a few doors, and that’s one of the reasons it’s different from a city bus.

School Bus

This is simply a bus that takes students to their school or university. In America, the colors in which you’ll see school buses are yellow and white — and this may differ in other countries.

Shuttle Bus

This is a bus that moves between several places without observing many stops. It’s often used during times for sport events and various other places where numerous people meet, and even at airports.

Mini Bus

This is a bus that’s just smaller than the normal buses. Its space can accommodate about 8-25 people.


This one is tagged as a “luxury bus,” one that’s quite smaller than the normal buses. It can accommodate about 8-25 people.

Double-Decker Bus

This is a bus that comes with up to 2 floors (decks). It can accommodate about 70 people. Some buses out there come with doors in the middle and also at the back and a few other buses only have doors at the front.

Single-Decker Bus

This particular bus has just one floor. It can accommodate about 30 people. Some buses come with doors in the middle and also at the back and some buses out there only come with doors at the front.

Low-Floor Bus

Among other buses, this one is closer to the ground, so anyone can easily get in and out. This exact bus is frequently used in cities. The floor is likely to get lower when the bus is at a place and higher when it’s in motion.

Step-Entrance Bus

A bus that has a couple of steps at the front. It does not move up or down from the ground.

Trolley Bus

This bus is just different from the other ones because it doesn’t make use of petroleum fuel — it draws energy from electric cables, those ones above the street.

Articulated Bus

This bus is flexible enough to bend in the middle so that it can increase its length and still go through small streets.

Guided Bus

A bus that’s guided on a completely different path, rails. Yes, you got that right — the rails for trains. But, you can make use of this bus on normal streets.

Neighborhood Bus

It can be compared to a school bus. It is transported around small streets.

Frequently Asked Questions (FAQs)

Why Does The Bus Driver’s Seat Bounce Around So Much?

Bus drivers sit for long periods, so seat comfort is paramount for job quality, hence the driver seat having its own springs and shock absorbers.

Like vehicle shocks, these wear out with use and become bouncier, so many drivers simply get used to the bouncy ride as it means less strain on their back anyway.

Why Are Buses So Bouncy – Conclusion

As a recap of the answer, we gave to the question — Why Are Buses So Bouncy? — we said:

The air suspension stands as the reason why bus bounces or is bumpy. The seats for the other passengers are closer to the suspension simply because the seats aren’t air pressure. On the seats of the bus driver is air pressure, because it’s the bus driver that stays in the bus even longer than the passengers.

Thanks for reading.

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