For a hot-blooded man (and many progressive women), the sound produced by a great set of motorcycle pipes as the monster approaches will always turn your head. Whether you’re a fan of American bikes –(I have a Harley Heritage Springer) or something from Europe or Japan, the sound of the pipes can be incredibly pleasing.
Motorcycle baffles are metal tubes that contain many perforations and are 2-4mm smaller in diameter than the exhaust pipe. The baffle is inserted into the muffler tube, also known as the exhaust. The perforations slow the airflow of the engine’s expelled gases, resulting in added back-pressure and noise reduction. You can wrap this perforated baffle with fiberglass or other materials to further reduce the noise level.
I’m guessing that if you’re riding a Hog – Harley Davidson – this is not something you are planning soon since that characteristic sound is a massive part of the appeal. However, in certain instances, there may be rules and regulations that legally limit the noise level your motorcycle can make.
For example, if you move into a neighborhood community that requires quiet (perhaps a hospital or Retirement Village is nearby) or a state you are traveling through on your motorcycle has strict noise limit laws.
Legal Noise Limits in Your Neighborhood or State
Many countries worldwide have clear legal guidelines regarding how loud your motorcycle is allowed to be. The USA is no exception, but noise limits vary significantly from state to state, and some states have no limits at all.
If you read my article ‘Are loud motorcycles really safer?’ I have listed within the article state by state laws regarding noise limits within the USA.
Regarding how loud your motorcycle is, you will need to be vigilant when you ride, or you might find yourself in problems with local law enforcement. This advice is particularly pertinent to riders who have increased the noise levels by removing baffles or other means.
Have fun, but don’t say you weren’t aware. It is your responsibility to check the noise law limits within the state you are riding.
Here are a few examples of state noise law limits in the USA:
- Alaska has no noise limits
- California has relatively confusing limits:
- A motorcycle manufactured before 1970 has a 92dB limit
- A noise limit of 88dB applies to motorcycles manufactured after 1969 and before 1973
As bikes became more efficient, the laws regarding noise volume tightened.
- An 86 decibel limit applies to motorcycles manufactured after 1972 and before 1975
- Motorcycles manufactured after 1974 and before 1986 have an 83dB limit,
And so on…
- Connecticut has various limits based on speed and location
- Michigan has limitations based on distance from the bike and the applicable speed limit.
As you can see, it’s not a case of one answer fits all states, and it’s imperative to know what each state expects from a noise level point of view from a motorcyclist.
You can also check the specific noise limit law for each state on the AAA Website by clicking the link HERE.
Do Baffles Have Uses Other Than Noise Control?
As you ride your bike, the exhaust system releases gasses, known as exhaust, and they create that glorious sound that exits from these pipes. The engine of a motorcycle can punch out 1,700 feet of soundwaves from the exhaust every second. It’s no wonder then that motorcycle exhaust systems can be so loud.
The exhaust baffles on a bike do not only control the decibel (dB) level emitted from the exhaust. These baffles also provide the back pressure necessary for an engine to perform at its peak ability. Baffles will accomplish these tasks by restricting the airflow at the end of a muffler or pipe.
Can You Remove Motorcycle Baffles?
You can remove the baffles, but be mindful that every motorcycle police officer in the area will be able to tell that your bike is over the noise limit, and you might get pulled over. In general, bikers are not at the top of a police officer’s list of priorities, but you may want to avoid the spotlight by keeping your motorcycles noise within the legal limit.
Do Baffles Need Replacing Over Time?
The baffles will need replacing after a time and replacement kits for baffles are available. It is a straightforward job to do yourself. After running for some time, your motorcycle’s exhaust baffles, and particularly any packing wrapped around them, can deteriorate. This deterioration may result in a noticeably louder exhaust and a drop in both power and performance.
An hour or less can bring your exhaust sound and performance back to where you want it to be.
Free-flow baffles provide less restriction and produce a much louder exhaust note. This thumping noise is terrific to hear, but if you find yourself living in or traveling through a restricted noise zone, you may want to muffle them.
Do You Need To Purchase A Ready Made Wrapped Baffle System?
We all love the sound of our motorcycles, but perhaps circumstances force you to make your bike a little quieter.
You do not need to purchase ready-made wrapped baffles. Instead of buying a ready-made baffle wrap to save money, you may consider making your motorcycle exhaust baffle instead of buying one.
Baffle wraps are not particularly expensive, I must say. If you compare the cost of purchasing a ready-made baffle wrap to wrapping the baffle yourself, the ready-made is much more costly. Still, why pay top dollar when you can have the fun of doing the job cheaply, from scratch, and learn more about your motorcycle in the process.?
Making your own wraps for the baffle is so easy, it’s difficult to imagine a reason for buying a set.
If you click HERE you can check out the same Fiberglass Muffler Wrap for Repacking Exhaust Baffle that I use.
How Do You Wrap Motorcycle Baffles?
- Find and remove your motorcycle’s fishtails. Depending on the motorcycle model you have, this may be easy or a little more difficult, and some fishtails can be disconnected using clamps on the exhaust and a bolt.
- Using a baffle, you have made or already own, measure its length and width
- Cut heat-resistant steel-wool or fiberglass to size
- Wrap the insulation around the baffle and tie it with stainless steel wire or similar. You may struggle to find stainless steel wire, but corrosion in the exhaust pipes makes this a worthwhile search.
- Replace the -now insulated- baffle in the pipe and close it up. Voila! One quieter bike.
How To Make Your Own Motorcycle Baffles
Perhaps you tried the baffle wrap method, and the drop in volume was not sufficient. The next step is to add more wrap, obviously, but you may reach a point where the wrap can no longer fit into the tailpipe. Here’s what you can do:
- Measure the diameter of the inside of the tailpipe of your motorcycle. Purchase steel tubing, whether in a store or online. This steel tubing should have a slightly smaller diameter than your tailpipe, around 1/16th inches smaller.
- Place your steel tubing into the bench-vise in your workplace. Have your hacksaw ready for this part. Cut the steel tubing down until it’s the correct baffle length (around eight inches for most bikes, but measure yours.)
- Mark the baffle for three offsets. Best to use a felt-tip marker for this. The first offset is three inches from the one end. The second is one and one-half inches from the first mark, and the third is three inches from the first mark.
- Secure the baffle vertically in the bench vise, ensuring the offset marks are visible above the vise. Make a horizontal crosscut halfway through the baffle at each of your markings using your hacksaw. If deemed necessary, reposition the baffle as you proceed. When done, remove the baffle from the vise.
- Put the baffle on the workbench, ensuring that the hacksaw cuts face upward. Secure the baffle in place using a couple of c-clamps.
- Place the tip of a cold chisel on the first hacksaw cut. Strike the cold chisel with a hammer or mallet, thus forcing the outer margin of the cut into the baffle’s center. Do the same with the other cuts to create the baffle offsets.
- Replace the baffle, this time having the three-inch end extending from the vise. Place a 3/16-inch drill bit into an electric drill (Doing this part with a hand drill is hell). Drill a hole one inch away from the end of the baffle and make sure it goes through both walls (of the baffle.) We require this hole for the stainless-steel bolt that holds the baffle in place in the tailpipe.
- Now drill a 3/16-inch hole through the tailpipe. This hole must align with the bolt holes in the baffle. Once installed, the outer end of the baffle should be flush with the end of the tailpipe. Secure the baffle in the tailpipe with a 1/4-inch diameter stainless steel bolt, lock washer, and nut. NB The length of the bolt will depend on the outside diameter of the tailpipe.
Job done! You have just made your very own baffle.
Conclusion
Your motorcycle has baffles fitted inside the exhaust pipe, which you can wrap with various materials to dampen (lessen) the noise produced. Wrapping will not damage your bike or cause a loss of performance and may save you a few dollars in noise fines in the long run.
Happy riding!
