What is a Motorcycle Baffle? How Does It Work? [Video]


What is a motorcycle baffle? Simply put, a motorcycle baffle is a perforated metal pipe inside of the muffler. Baffles are designed to create backpressure and dampen engine sounds before they leave the exhaust system. This is why these parts are also known as motorcycle exhaust silencers. Besides being on motorcycles, baffles are virtually used in all vehicles to keep the sound below legal noise limits.

If you want to find out more about this key part, you are in the right place.

We at PowerSportsGuide have compiled the basics of motorcycle baffles under one roof!

What is a Motorcycle Baffle?

If you cut a motorcycle muffler in half, in most cases you can see two (or sometimes three) pipes of different diameters. The pipe with the larger diameter is the muffler’s housing, which is what you see from the outside. The smaller pipe inside the housing is the baffle.

Motorcycle baffles come in many different sizes, shapes, and materials, but all of them do basically the same thing.

The two main roles of motorcycle baffles are to dampen engine noise as well as create backpressure in the exhaust system.

Without baffles motorcycles would be too loud, which would be annoying for the rider as well as the environment.

This is why motorcycles with “straight pipe” exhausts are illegal in most states. 

Now without further ado, let’s drill into the details and check how motorcycle baffles work!

How do Motorcycle Baffles Work?

Motorcycle baffles work in a very simple way. In a nutshell they slow down the pulsating air coming from the engine and turn it into a more even airflow. This is the key for reduced exhaust sounds, as a slower and steadier airflow is always significantly quieter. To achieve this, motorcycle baffles make the airflow path longer and more difficult.

Because of this, longer baffles produce quieter sounds. Besides their dimensions the surface of the baffles is no less important.

If you take a close look at a motorcycle baffle, you can see many little holes on its surface, which are designed to break up, and dampen the sound waves.

You can typically see a few bigger holes on shorter baffles, which makes it easier for air to flow. In contrast, you can find many quiet motorcycle buffers on the market that typically feature a lot of little holes.

These designs virtually work like different pasta strainers. The bigger the holes on the strainer the faster water passes through it. If a strainer features tiny holes it holds the water for much longer.

The same is true with quite baffles, their small holes make it much harder for the air to flow through.

What’s more, many of these quiet baffles are wrapped with a coat of insulation fiberglass material for greater efficiency. Sadly, these bulky wrapped baffles do not fit in every muffler.

Besides dampening the engine noise, baffles also create some backpressure in the exhaust system. This pressure can help the engine to function properly as well as prolong its life.

Moreover, backpressure always increases fuel efficiency and low-end torque.

Are you interested in how motorcycle baffles affect performance? Keep reading!

Do Motorcycle Baffles Affect Performance?

The general rule is that motorcycle baffles always affect the performance of the engine as they lower the airflow through the engine. This means in many cases that removing the baffle can add some HP. But contrary to popular belief, removing the baffles doesn’t necessarily mean higher performance. On many bikes you can expect the same performance without baffles, while others may deliver even less power!

Finally, the result always depends on the features of the exhaust system and the engine.

Since the performance, engine layout, and design of motorcycles vary from one model to the next, you rarely find two completely similar bikes on the market.

Some of them are designed for maximum performance, while others do a good job on longer tours. This is why their exhaust systems are vastly different.

As we’ve discussed above, baffles provide some backpressure in the exhaust system, which affects engine performance. Because of this, it’s commonplace among riders to think that removing a baffle makes a bike more powerful.

While it’s true in many cases, this performance increase is usually marginal. What’s more, on many modern motorcycles baffles can even add some power instead of robbing it.

How it this possible?

The exhaust of new bikes is a complex and carefully designed system that works together with the engine. Therefore, tinkering with this system can cause more harm than good in many cases.

This means that backpressure in a well-designed exhaust system allows the engine to run optimally, which can even result in better performance. Although, this is only true under certain conditions.

On many bikes the baffles may hold back some HP, especially if the muffler is designed incorrectly. Finally, it always depends on the make and model.

As you can see on this video, this bike puts out the same performance even with an open exhaust.

Many riders may argue with this and believe removing baffles always means a ton of extra power. This is often justified by the fact that drag bikes don’t feature baffles to get the most power out of the engine.

Although it’s true let’s face it, drag bikes run at much higher RMPs than average stock motorcycles. And as long as drag pipes can increase efficiency at higher RPMs they have much less effect on performance in lower ranges.

And unlike drag bikes, the majority of stock motorcycles run at much lower RMPs most of their life, especially V-twin cruisers. Consequently, removing baffles on many bikes translates to very little extra power.

The other main reason why so many riders think their bikes are more powerful is because of the louder exhaust sound.

Do Quiet Baffles Affect Performance?

Another urban legend is that quite baffles rob too much engine power. Fortunately, this is not true! Even if quite baffles may slightly affect performance, the difference is typically not noticeable by the rider. Surprisingly, the power decrease is detectable only on a dyno test in most cases. (And even the dyno very often gives very similar results!)

If you want to be convinced of this, don’t miss this comparison test on a dyno:

Is it Bad to Remove Baffles on a Motorcycle?

Yes, many experts say that removing motorcycle baffles is a very bad idea. Each stock motorcycle features baffles, and with good reason. They help to increase the efficiency of the bike and can extend engine life. Baffles are also important in keeping the engine sound within legal noise limits. Therefore, removing them is definitely not recommended!

Keep in mind that if you ride your bike without baffles it may end in a ticket because of the loud exhaust.

Another drawback of removing baffles is that it always leads to lower low-end torque because of the lack of backpressure. Finally, it can result in a worse riding experience.

What’s more, the change in airflow can foul the bike’s fuel-delivery or ignition system, which can cause poor fuel economy, fault codes appearing, and even other malfunctions.

Unfortunately, many owners remove the baffles on their bikes. These machines are typically dirt bikes or cruisers powered by V-twin engines. Both of these are very loud without baffles!

Does Removing the Baffle Void the Warranty?

Yes, another con of removing the baffle is that it may void the warranty. Although this always depends on the dealer, making aftermarket modifications often affects the warranty. And believe it or not, removing baffles is considered a performance modification as it affects the engine. Therefore, just this small modification can void the warranty on your bike!

How Can You Make Your Motorcycle Baffles Louder?

You can make your motorcycle baffles louder in many ways. For instance, you can remove the insulation wrap from the baffles (if they feature), you can cut them shorter, or you can drill bigger holes into it. You can also consider replacing them with some aftermarket baffles. But don’t forget that tinkering with the baffles can make your bike too loud and lead to engine malfunctions, as well.

Because of these risks, best practice is to prefer stock baffles.

How do You Remove a Stuck Baffle from a Motorcycle?

Removing stuck baffles from a motorcycle can sometimes be tricky, as they are prone getting stuck really hard. Since no two motorcycle exhausts are the same, there is no magic recipe for the process. But depending on the design of your baffles you can try to pull them out with nose pliers, or some DIY tools made from wire coat hangers, or some nuts on a string. Let’s see how to do this step-by-step!

  1. Before trying to remove the baffle from the muffler, make sure that it’s already cooled down. Baffles on bikes are usually fixed with one or more bolts, so make sure you remove all of them.
  2. Then, apply some lubricant (like WD-40) on the edge of the baffle.
  3. As the final step, grab the end of the baffle with nose pliers and try to pull it out.

Unfortunately, this won’t work on many bikes if the baffle is hard to reach.

  1. In this case make a tool from two wire coat hangers or two pieces of strong wire.
  2. Plug them into the baffle and hook them into two holes on opposite sides of the tube.
  3. Finally, pull the wires with pliers, vice grips, or another tool.

Another trick is to wrap the other ends of the wires around a piece of wood. (You can even hammer the wood gently if it’s needed.)

Or thread a rope through some bigger nuts while attaching the loop to a piece of wood. Insert the nuts one-by-one into the baffle, and if they are “hooked” try to pull out the baffle.

If it is very firmly stuck, you may need an extra hand to hold the bike and apply the brakes.

Here’s a good video on how to remove a stuck baffle from a motorcycle:

Disclaimer: Keep in mind that this process can go wrong in many ways, as you can damage the bike or even yourself. If you lack skills or tools, the best practice is that you take your bike to a service shop!

How Do You Put a Baffle on a Motorcycle?

Unlike removing, installing a baffle on a motorcycle is typically a much easier task. Just make sure the new baffle perfectly fits in your bike and slide it into the muffler. If it features a wrap you may want to rotate it slowly to avoid creasing the material. Once the baffle is in place replace the bolts as the final step.

Conclusion

As you already know, baffles on motorcycles are perforated metal pipes inside of the muffler. The main purpose of these parts is to dampen the engine noise to keep it below legal noise limits. They also create some backpressure that helps the engine operate efficiently and properly.

Contrary to popular belief, removing the baffles doesn’t cause a significant increase in performance. What’s more, in some cases the lack of baffles can cause even less power! This always depends on the design of the exhaust system and the engine.

As a final word, don’t forget that removing or modifying baffles may void the warranty of your bike, and can lead to legal issues because of the louder exhaust sound!

References:

https://itstillruns.com/pros-amp-cons-exhaust-baffles-6955362.html

https://www.revzilla.com/common-tread/motorcycle-exhaust-101

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