Veteran revheads have long contested that loud exhausts on motorbikes not only help them go faster, but can be a lifesaver for riders and others on the road. In fact, I’ve been a disciple of this school of thought myself for many years. But after four decades in the saddle, recent events and a little research and reflection have convinced me that we may be labouring under an illusion when we claim that “loud pipes save lives”.
I don’t think I’m going to make many friends arguing this – particularly among the road warriors and hog-riders who love the roar and grunt and oily scent of a big, hardworking combustion engine. But please bear with me, as I try to explain why I’ve not only stopped believing that loud exhausts are lifesavers, but that the world might actually be a better place without them.
The “loud pipes” statement has been around for decades, and inevitably pops up when there’s a perceived threat to what many feel is their God-given right to a loud exhaust system. Safety might be the most common argument, but within the tent of the motorcycling enthusiast there’s an understanding that noise means performance – and a louder or throatier exhaust just sounds right, doesn’t it?
Before we get into the question of safety, let’s look at the relationship between performance and noise. If you look back in time to the early days of the combustion engine, people soon learned that by allowing exhaust gases to escape the engine as quickly as possible (i.e. with less restriction in the exhaust pipes) it resulted in a performance gain. Top speeds and quarter mile records duly tumbled as racers tuned their exhaust systems to help them go faster. As a result, not only has performance improved, but noise has also increased – as many of you have witnessed when being in the general vicinity of a racing bike.
In these circumstances if you’re not careful you run the risk of hearing damage, but there’s no escaping the fact that you’re aware that there’s a vehicle in your immediate vicinity. Ipso facto, noisy exhausts not only deliver better performance – they’re also a natural safety feature, right?
Noisy exhausts are all very well for race meetings, which we love to attend to see our heroes performing death-defying deeds for our entertainment. We also want to emulate what we see and hear by fitting a performance exhaust to our own road bikes so we can pretend to be Marquez or Bagnaia.
However, the downside of all this noise is that, on suburban streets and country roads, many people are annoyed by what they hear and the polluting gases they have to breathe in. Over the years, our governments have duly imposed more stringent noise and pollution limits, pushing the motorcycle industry to create new solutions like fitting catalytic converters in millions of exhaust mufflers –naturally resulting in quieter bikes coming off the production line.
While it’s difficult to argue against the health benefits of these constraints, it does require manufacturers to spend more money in development to meet these more restrictive targets – with a natural flow-on effect to riders in terms of vehicle prices. Oh, and that quietness – surely that will result in more accidents?
So this “quietness” has become the main justification for arguing for loud pipes. After all is said and done, if you can’t hear the bike then the already exposed motorcyclist is at greater risk of being hit by a car or truck because the driver doesn’t know they’re there – or a pedestrian is more likely to walk out in front of the bike for the same reason. So our loud pipes are helping us reach our road toll target “towards zero”. Well… not quite. The above argument isn’t really based on any firm scientific evidence. In fact, when science is brought into the equation, the argument starts to look a little shaky.
In 1981 the US Department of Transportation commissioned a study to identify motorcycle accident causes, rate the effectiveness of protective equipment, and identify countermeasures to prevent accidents and reduce injuries. They studied and reconstructed 900 accidents, taking into consideration a whole raft of inputs including whether the rider had their headlights on, whether they were wearing a helmet, their age, sex, alcohol and drug status, the weather, the time of day, their level of training and experience, and so on.
This study became known as the Hurt Report (the name of one of the three authors – oh the irony) and ran to 425 pages in length. There were many reasons for motorcycle accidents, but in summary its main finding was that the most common accident “involves another vehicle causing the collision by violating the right-of-way of the motorcycle at an intersection, usually by turning left in front of the oncoming motorcycle because the car driver did not see the motorcycle. The motorcycle rider involved in the accident is usually inconspicuous in traffic, inexperienced, untrained, unlicensed, unprotected, and does a poor job of avoiding the collision.”
If you picked up on the words “inconspicuous” and “in front of”, I can hear you shouting, “loud pipes make you more conspicuous and therefore prevent accidents!” Well, again, not quite. In 30% (that’s 270) of these 900 accidents, the motorbikes actually had modified exhausts. Also, as the driver was facing the motorcyclist in the above scenario, shouldn’t they have seen them before causing the accident? So why didn’t the noise from the 270 motorbikes prevent the accident? Is it because noise wasn’t a factor in most of these accidents? It’s worth considering the noise from a motorcycle is initially moving away from the bike and the vehicle the bike is approaching. To my mind, this further undermines the wisdom of the “loud pipes” argument – and suggests that other factors could be more effective at preventing accidents.
Fast forward to 2021 and a study carried out by the Romanian Association for the Development of Motorcycling, together with the Polytechnic University of Bucharest’s Department of Motor Vehicles. Their study focused on exhaust noise from a set of motorcycles and their tests revved engines to the red line at various distances around the test car – for example, 15 metres behind the car, 10 metres behind, right next to the car, and right in front of it. They also varied the interior noise levels by having the windows rolled up or had the car’s engine gently revving and the radio playing.
What they found was that, 15 metres away (or just over three car lengths), an exhaust emitting 110 decibels (that’s comparable to a loud rock concert, or a power saw or jackhammer at close proximity) was not heard in the car. Even when the bike was next to the car, the exhaust noise from just one bike was heard over the ambient noise in the cabin and the rest were barely detectable. Interestingly, they found that when the bike was in front of the car the loud pipes made no difference at all. So do you still think loud pipes save lives?
The reason why you can’t really hear these loud exhausts as bikes arrive and pass you is due to something called the doppler effect. In simple terms the further behind or in front of you the bike emitting the noise is, the quieter it seems. It’s only as it gets closer that, due to the compression (increased frequency) of the emitted soundwaves, you can perceive a change in volume, then as it passes you it seems to get quieter as the soundwave frequency expands. From the rider’s perspective, they hear the noise of the bike’s exhaust at a constant volume because they’re travelling with the noise source, so do not experience the compression or expansion of the emitted soundwaves.
How many of you have had a fright as a bike whizzes past you as you sit at the lights, because you were caught by surprise? One second it was all Elton John and Bennie and the Jets, then there was a surge of noise that scared the bejeezus out of you, then it suddenly got quieter again. That’s the doppler effect, baby! So yes, you do hear the exhaust eventually – but only when the bike is right next to you. You do not get the benefit of an early warning when the bike is arriving – so our hypothetical car driver or pedestrian would have no time to react and avoid a collision.
Now let’s look at what is happening now and into the future. Yep, I’m talking about electric vehicles (EVs) and I’m really focusing on electric motorbikes. These things are here to stay: their numbers are only going to increase and they don’t have exhaust pipes, which makes them exceedingly quiet. If you still believe that loud pipes save lives then I’m sure you’ve concluded that it’s going to be carnage on our roads the more that EVs replace combustion-engine bikes.
To counter this fear, some manufacturers are providing artificial sound systems that can mimic the noise of a combustion engine for their electric bikes. I’ve seen a few on YouTube and yes they do the job, but the funny thing is that you can use any sampled noise on these systems – so if you want to make your bike sound like a jet fighter, a screaming Formula One car, or a herd of mooing cattle, that’s entirely possible. But considering these would have the same decibel restrictions for noise emissions as current bikes, will they really make drivers more aware?
I think not, for all the reasons that I’ve already shared. In fact, I don’t think EV motorbikes are going to make the situation worse than it is now in any way – and we may as well embrace them for all the other good things that they can do. I’ve ridden a couple and have loved the experience, and I can’t wait to get my own EV one day. As Mr Dylan said, the times they are a-changin’.
In my opinion (it’s not scientific I know, but it is based on 40-plus years of riding and driving), if you really want to reduce the number of motorcycle accidents, the biggest bang for your buck will be upskilling all our road users – drivers and riders alike.
Looking back at the Hurt Report, after the rider being inconspicuous in traffic, the next reasons for motorcycle accidents were inexperienced and untrained riders. There is an unfortunate lack of support when it comes to safe motorcycling in Australia and while companies like HART, Stay Upright, and the Motorcycling Council of NSW are doing a fantastic job in promoting rider awareness and offering courses for all levels of riders, these can be costly to the individual – and many initiatives don’t see the reach they need without government backing. Offering government subsidised rider training courses and backing industry safety initiatives would go a long way to keeping our riders safe out on the road.
In 2021 the Motorcycling Council of NSW surveyed more than 500 riders to capture motorcyclists’ views of driver behaviours that have affected their safety, and what can be done to improve safety on the road. The results showed that 93% had had a near miss on their motorcycle and 88% of drivers in a near miss were believed to be disobeying the road rules (not looking in mirrors, slowing down too late, or being distracted while driving).
I believe the levels of car driver skill and competency in this country are too low across the board, and I attribute this to a seriously flawed and inadequate system of new driver training. From my personal experience on the road, many car drivers appear to be disconnected from the whole driving environment, cocooned by the noise-deadening qualities of their cars – which are often, in turn, exacerbated by listening to music or podcasts through noise-cancelling earphones. They’re also distracted by Facetiming their partners (oh yes, I’ve seen it), watching videos (seen that too), texting, eating, drinking, or putting on makeup in their mirror at 80kph (I’ve lost count of the number of times I’ve seen this). Or they’re just not looking when changing lanes because they’re so worried about losing the opportunity to gain two metres on the car next to them.
In all these scenarios, I believe that loud pipes would make no difference whatsoever to preventing an accident with a motorcycle. As for pedestrians, the pandemic that is social media has resulted in more pedestrians not looking where they’re going, or wearing earphones that cocoon them from the outside world. I’ve had so many pedestrians on their phones walk in front of my Harley-Davidson, which has Vance & Hines mufflers whose baffles seem to have fallen out (ahem – yes sorry, it can be quite loud, Your Honour), and it was only the use of the horn that finally got their attention.
Ok, let’s get a little more positive and back to the main reason for this blog – namely whether your loud exhaust will save you out on the road. It’s important to understand that there are many benefits to the rider and the wider community from our growing switch to electric vehicles. An obvious one is the lack of emissions; another is the instant torque that will get you out of a tight spot quicker than any combustion engine. And then, of course, there’s the reduced noise pollution. I live next to a busy road and all that noise does become an irritant and occasionally also interferes with my sleep. Studies suggest that noise pollution can increase blood pressure and impact children’s ability to learn, and we know it can definitely cause tinnitus and other hearing impairments. So by having EVs contributing to a quieter environment, surely this will mean a net positive gain for us all.
After a lot of reading and reflection, I personally can no longer support the argument that loud pipes save lives and I believe that the proliferation of quieter electric motorbikes is not going to be the cause for an epidemic of accidents. But until some of the issues I’ve highlighted are addressed, we will have to keep taking the initiative to protect ourselves. I think it’s extremely worthwhile taking regular courses to keep your riding skills updated, such as the Honda HART, Stay Upright, or the intriguing MotoDNA course. More importantly, never stop assuming that everyone is out to get you – and tailor your riding accordingly.
Phil Carter has been riding on the road for more than 40 years and hasn’t killed himself or anyone else, which he is proud and relieved about. He’s owned several motorbikes, including a Kawasaki KH100, RZ350LC, GSXR750 slabbie, Kawasaki Z650, KMX200, and Norton Model 50. He currently rides a Harley and a Honda Hornet, and is looking forward to owning his first electric bike.
References and further reading
Noise Exposure and Public Health - TNO Prevention and Health, Leiden, The Netherlands; Department of Health Risk Analysis and Toxicology, Universiteit Maastricht, Maastricht, The Netherlands