A good exhaust note is one of your motorcycle’s most visceral aspects. The connection from your ear drums to your right wrist plays an undeniable part in raising your pulse, making aftermarket exhausts one of the most common mods on a new motorcycle. But if you’re going down that road, just know there’s a lot more to think about than amplified acoustics.
A good aftermarket motorcycle exhaust will enhance performance and cosmetics, while a bad one may leave you with a deafening drone and a fix-it ticket. We’ve just added a line of killer stainless steel exhaust systems from Stealth Pipes Inc. to the Bike EXIF Store, ranging from the Honda Monkey to the new M8 Softail. To celebrate the occasion, we’re highlighting five key points to consider when selecting an aftermarket exhaust, and encourage you to consider handmade stainless offerings from Stealth.
Know Your Goals There are loads of advantages to be had by upgrading your exhaust system, including weight savings, performance increases and the all-important exhaust note, but it’s awfully hard to pick the right exhaust system if you can’t definitively say what you’re trying to accomplish.
It sounds incredibly obvious, but many riders fail to consider this simple question before buying the cheapest exhaust that’ll fit their bike. And sure, that slip-on might cost as little as $50 on Amazon, but if the manufacturer can’t guarantee its results, what do you think yours will be?
Ultimately, the goals of your modification program should be reflected in the exhaust you choose, whether it’s lighter weight, a bump in performance or simply a more pleasing soundtrack.
Types of Exhaust Systems Now that you know what you’re trying to achieve, it’s time to see what it’ll cost. The two most common motorcycle exhausts you’ll find are slip-ons and full systems, with each bringing their own blend of pros and cons to the table.
Slip-ons The most simple and cost-effective way to modify your motorcycle’s exhaust system is with a slip-on. Named for the slip joint between the muffler and header pipe, slip-ons usually require only a couple of bolts for installation and work with factory header and mid pipes. Since mufflers are responsible for the majority of sound and weight of an exhaust system, slip-ons may be enough to satisfy your requirements, and quality offerings can be had for 75% less than a full system.
While a slip-on is certainly the best bang for your buck, it’s worth mentioning that its primary advantages are sound and weight. You may free up a little extra power, but if you’re really looking to add horses to the stable, you’ll have to pony up for a full system.
Full Exhaust Systems A full system includes the rest of the pieces to complete your exhaust upgrade, including header pipes, mid pipes and a catalytic converter (if so equipped). Often made from lighter materials and larger-diameter pipes, the complete system is engineered by the manufacturer to provide a more substantial upgrade in flow, torque, and horsepower.
Other than a more complex installation, the biggest downside to a full exhaust system is the cost. Expect to spend north of $1,000 for a good system from a reputable manufacturer, and unfortunately, that’s without taking supporting mods into account. While you’ll have to pay to play, a quality exhaust system can transform the look and feel of your motorcycle by freeing up weight, adding power and providing some stellar TIG welds to gawk at.
Supporting Modifications Modern motorcycle exhaust systems are tightly regulated in the emissions and decibels they produce. A bike like my Honda CRF450RL runs very lean straight off the showroom floor to meet emissions, so imagine the consequences of installing a freer-flowing exhaust system without adding more fuel.
This situation is hardly unique, and anytime you’re modifying your exhaust, you’ll want to research if more fuel will be required through an aftermarket fuel management device. If your bike’s a little older, a slip-on may pass with factory fuel mapping, but it always pays to do your research.
Complete exhaust systems may also require further modifications to the airbox or other systems to achieve full advertised performance.
Materials OEM and aftermarket motorcycle exhausts are available in a range of materials, most commonly steel, stainless steel and titanium. For aesthetic purposes and lighter weight, carbon fiber may also be used on motorcycle mufflers.
Steel Regular old steel has long been the standard for OE exhaust systems since it’s durable and cheap to push out by the thousands, but it is heavy and susceptible to corrosion. Steel exhaust systems will go the distance if you keep up with them, but that could mean restoring your exhaust pipes multiple times during ownership. If pitting from corrosion becomes an eye sore, or you’re ready to push your bike to the next level, upgrading to a lighter, freer-flowing system is one of the best upgrades you can make.
Stainless Steel The OEMs have been gradually turning to stainless steel as the new go-to material for exhaust, and if your bike was manufactured within the last decade, there’s a good chance you’re already equipped. Stainless is made by combining iron with chromium to create a strong and corrosion-resistant alloy, and it can always be restored to its original finish if it tarnishes. Stainless is also quite strong, meaning headers and mid pipes can be made from thin-wall tubing for additional weight savings.
With strength and corrosion resistance to its credit, stainless steel is an ideal choice for aftermarket exhausts, offering significant cost savings over titanium and carbon fiber. Full stainless systems don’t come cheap (expect to pay $1,000 and up), but quality stainless always looks good and develops heat coloring from blue to bronze.
Titanium If you’re chasing ounces, instead of pounds, or simply need the highest end material available for your build, titanium is the answer. The bad news is that it’s expensive, due to the extensive processing needed to take it from rutile or ilmenite ore to titanium tetrachloride, and finally, pure titanium. That means that a full system for a single-cylinder bike can cost $2,000, and a whole lot more for a multi-cylinder engine.
What you’re paying for is a system that weighs 50 to 70% less than stock, has excellent corrosion resistance and develops that beautiful blue, purple and orange coloring with heat. While titanium is quite strong, be aware that the thin-wall tubes are more susceptible to impact and far more difficult to repair.
Carbon Fiber Everyone loves the intricate weave and strength of carbon fiber, and the lightweight material has proven adept for use on aftermarket mufflers from companies like Akrapovič, FMF and Yoshimura. While carbon fiber demonstrates weight savings over titanium in silencers, and will stay cooler than steel, there are several downsides to be aware of.
Beyond the high price tag, carbon fiber is only strong in the direction of the weave, meaning a direct impact may cause it to crack. Carbon will also deteriorate if it spends enough time in direct sunlight.
Street Legality Sure, the legality of aftermarket motorcycle exhaust is a bit of a buzzkill, but probably not as much as getting a fix-it ticket from your local PD. Since the specifics vary based on where you ride, we’ll cover a few points in broad strokes.
At the national level, the Environmental Protection Agency (EPA) and the Department of Transportation (DOT) set emissions and noise standards for motorcycles. Aftermarket systems that remove or alter the factory-installed catalytic converter or exceed noise limits typically violate EPA regulations, making them illegal for street use. The California Air Resources Board (CARB) enforces even stricter emissions rules in California, requiring exhaust systems to be CARB-certified to be street-legal.
Beyond emissions laws, noise ordinances vary by state and municipality. The Federal Noise Control Act established a nationwide standard, but enforcement is largely left to local governments. Many states use the Society of Automotive Engineers (SAE) J2825 standard for motorcycle exhaust noise, while others impose decibel limits ranging from 80 to 100 dB at certain RPMs. Some areas allow law enforcement to issue citations based on subjective noise judgment, leading to inconsistent enforcement.
For riders, the key takeaway is that not all aftermarket exhausts are illegal, but they must meet federal, state and local requirements to be used on public roads. Many manufacturers offer EPA-compliant or CARB-approved systems, and some states allow non-compliant exhausts if the bike is registered for off-road or closed-course use only. Before swapping out an exhaust, it’s best to check the specific regulations in your state to avoid fines, equipment violations or trouble at annual inspections. A little restraint goes a long way in our experience, so if you’re going to modify your exhaust, be mindful of where and how you ride.
Photos courtesy of Stealth Pipes Inc., Akrapovič, Honda & FMF Racing
