Motorcycle Exhausts - A Buyer's Guide

Replacing the standard exhaust on your motorcycle is one of the most common aftermarket upgrades. But before you rush out and buy a new end can or full system take the time to read through our buyer’s guide that will ensure you get the best exhaust at the best price for your bike.

QUESTION: What's the main reason for changing your exhaust?

A good question to ask before you start your search is what is the primary reason for wanting to change your standard exhaust? We asked a survery of this site's users what their main motivators were and we received a varied response. Here's a selection, one if not more of these will be true of you and will certainly influence your choice

ANSWER: Performance Increase

According to our poll, over 43% of riders upgrade their exhaust to get more power from their engine. If this is true for you, you should consider a full system as opposed to changing the new end can (silencer) as the performance increases will be more pronounced. There are cost considerations here which we cover in more detail below. Another aspect of performance improvement to be had from a change of exhaust is weight saving. Performance exhausts are all considerably lighter than the stock exhaust they replace, for those wanting to trim the weight of their machine this is a good thing. Some materials will result in greater weight saving than others, carbon fibre cans being particularly light. See more on choice of materials below. If you’re planning on racing your bike then performance increases and weight saving will certainly be on your shopping list.

As a benchmark you can expect a change of end can to produce around a 5% increase in your bike's power output. A full system with improved air filter and fueling could exceed a 10% increase.

ANSWER: Sound - A different exhaust note

Second in our poll was a desire to change the sound of the bike. If you’ve ever heard an engine fire with no silencer you’ll know how loud it is. Bike manufacturers are required by law to limit the noise an exhaust emits (see more on regulations and sound levels here), but in so doing they detract from the raw appeal of a tuned engine as fitted in most superbikes. If increasing the sound or changing the exhaust note of your bike is your primary aim when upgrading you have decisions to make between a road-legal and race exhaust, again see more on this below.

ANSWER: Improved looks

To satisfy increasingly stringent exhaust regulations standard exhausts are getting bigger and bigger (take a look at our worst exhausts article for some of the biggest culprits). While bike manufacturers are doing their best to conceal the bulk of these exhausts, either under the seat on with stubby moto-gp style cans exiting under the bike, many standard exhausts are ugly and detract from the ultra-sharp stylish lines of the latest bikes. If improving the look of your bike is your main aim then you have decisions to make about the material your end can is finished in (see more below on materials), and also the style and shape of the pipe.

ANSWER: Better build quality or damage to stock exhaust

Finally you may be motivated to change your exhaust simply because the standard exhaust was damaged in a crash or has rotted through. Often OEM (see glossary) replacement exhausts costs as much if not more as their performance replacements. Motad in particular do a strong line in quality exhausts made from premium materials built for longevity that are very competitively priced.

Budget

Aftermarket exhausts range from just over £100 for a low-end replacement silencer through to over £2000 for a custom race-spec full system from one of the top manufacturers. You’ll know how much you have to spend on an exhaust which to a large degree will dictate your options on manufacturer and material. Titanium exhausts for example typically cost around £50 more than the same exhaust made from aluminium. Another rather obvious consideration is how many exhausts your bike has! If you have two silencers exiting either side of the bike or under the seat replacing them will usually cost twice as much as replacing a single silencer. I say usually because another option available to you is to go with a two into 1 exhaust losing one of the silencers. This will significantly reduce weight but may affect the engine characteristics of the bike and its more likely a session on the dyno will be required. Click here for more information on bikes with the option of a two into 1 system.

Fit yourself or use a mechanic

Fitting an aftermarket exhaust is not a particularly complicated task and all exhausts now come with fairly comprehensive instructions, see our Exhaust Fitting Guide for general instructions. However, if you’re the sort of rider who typically trusts all servicing to your local dealer then you might decide to get a professional to fit the exhaust as well. Remember to keep hold of the standard can and ensure the mechanic makes it easy to switch between the two if you’re running a slip-on end can as you may need to swap back come MOT time. Typically a metal collar will be fashioned to allow this. If you’re replacing the full system then you’ll definitely need to remove the lower fairing on a fully-faired bike and most probably also remove the radiator to gain access to the manifolds. This won’t be necessary for some bikes, and on others you can tilt the radiator upwards without having to drain it and replace the coolant. Expect around an hours labour to change an end-can and between 2 and 3 for a full-system. At typical hourly labour rates that’s about £50 for an end can and perhaps £150 for a full system. Whether you’re taking on the job yourself or using a professional make sure you have good clearance between the fairing and the pipework otherwise you’ll end up with an unsightly melted patch in your belly pan.

Full-system or End Can

If money is no object and outright performance is your ultimate goal then a full system is the way to go. A full system is all the pipework from the gaskets at the cylinder outlets right through to the end can. Many riders overlook the improved efficiency of gas flow that can be found in aftermarket pipework. Many of the larger manufacturers like Micron and Akrapovic hydroform their pipework to achieve this optimum flow. As a rule of thumb you can expect to pay at least as much again, often more, for a full system against just replacing the end can. Of course, if your downpipes have rotted, as if often the case for many bikes with mild steel pipework as standard, then you may only need the pipework and no end can.

Road legal or race use only

Another choice you’re faced with selecting your new exhaust is which side of the law you want to ride on! Exhausts come into two types, those that are homologated for road use and bear the appropriate stamps (see our regulations page) and those that are technically only for race use. Those that are for race use will typically be louder and in some, but not all cases offer enhanced power increases. If you intend to use a race can on the roads you need to be prepared for the fact that you might get a tug from your friendly local copper, see our guide to how to handle such instances. You will also probably need to switch back to the standard exhaust come MOT time.

If you’re only planning on using the exhaust on the track then you’re still not out of the woods as all UK circuits operate a dB noise limit on vehicles using the circuit. While some are more strictly enforced than others its worth bearing in mind as that’s nothing worse than being turned away from a track day for excessive noise before your tyres are even warm day. See our article on track day noise limits for further information.

Exhaust manufacturers have recognised that most riders want the best of both worlds, a howling high performance exhaust on the track (or where you can get away with it on the roads) and a road legal exhaust come MOT time. Thank god for the invention of the removable baffle! These ingenious devices are inserted into the main chamber of the silencer and can be removed with a pair of pliers or similar. When in place the noise of the exhaust is limited to within acceptable levels for road use, when removed it will howl as the manufacturer intended! See our article of those manufacturers that offer exhausts with removable baffles.