The sound of silencepds1.egloos.com/pds/200812/24/32/helmet-silence.pdf · 2008. 12. 23. · The sound of silence A noisy helmet can ruin not only your day, but your hearing. RiDE

100 RIDE APRIL 2006

The sound of silenceA noisy helmet can ruin not only your day, but your hearing. RiDE investigates which helmets are a headache and those that give your lugholes an easier time

KIT TESTKIT TEST

What we didWe recorded the noise levels inside 18 different helmets to see which gave the lowest and highest sound readings, so that we could inject some science into the debate about which helmets give a noisy ride. To ensure consistency, the same bike, rider and location were used as we took sound readings at four different speeds.

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Recording equipmentStep one was to devise a system for recording the noise at a rider’s ear. With the help of intercom fi rm Starcom (www.starcom1.com), we removed the speaker from one of their in-ear headsets and replaced it with a tiny microphone. The headset, connected to a sound meter to show the decibel level being picked up at the microphone, was worn under each helmet in turn. This method has its limitations, as the microphone is in a plastic housing that goes in the ear, restricting some noise from reaching it. Also, the microphone holder blocks off some of the ear cavity, so the noise isn’t exactly as you’d hear while riding, but it is very close. The ideal would be to implant a microphone at the base of a rider’s ear drum, but we couldn’t fi nd a surgeon willing to carry out the operation. What we can promise is that each helmet was tested identically, making it a valid comparison.

The bikeWe attached the sound level meter next to the clocks on our test bike, a Kawasaki ER-6n. This allowed the rider to monitor speed then easily check the decibel reading. We chose a bike with no fairing or screen because it allows a cleaner fl ow of air around the helmet. Often, wind noise heard while riding a bike is accentuated by a screen as the air can be directed straight at your head. If we’d tested the helmets on a bike with a screen, the rider’s posture could also have affected the result. The air from a screen could hit each helmet in a different area, depending on his riding position, and caused a difference in readings between the helmets.

The testsOur rider was former World Endurance racer Dec Crutchlow. The cable to the sound meter was held in place by a necktube to eliminate the possibility of noise being picked up from the cable. Helmet vents were closed and visors down. The test was conducted on a straight section of Bruntingthorpe Proving Ground in Leicestershire – a traffi c-free environment, ensuring no extraneous noise was picked up. We did runs at 60, 70, 80 and 90mph. Each run was conducted in two directions as wind direction has a bearing on noise levels. Some manufacturers claim wind tunnels are the only accurate way to record noise levels in helmets, but we prefer real-world testing – studies have shown that fi gures for wind tunnel testing and road testing are similar. Weights quoted are actual weights for the test lids (the helmets tested were large sized). Prices are for plain colours.

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ANOTHER helmet which is noisier at 60mph than the test-winning helmet is at 90mph – and it’s noisier by 3dB, which is a signifi cant amount. On average, this helmet recorded 98.8dB at the four different speeds. The OGK is another helmet which has a ‘dirty’ shape, thanks to a large vent over the crown of the shell. It peaked at 103.5dB at 90mph. It was the noisiest on test when worn at 70mph, but only by fractions of a decibel. ■ At 60mph – 94.9dB ■ At 70mph – 97.6dB ■ At 80mph – 99.3dB ■ At 90mph – 103.5dB ■ Average – 98.8dB

■ Weight 1654g■ Contact: 01768 483784

With an average noise level of 99.6dB, this was the noisiest helmet on test by a considerable margin. It recorded the highest peak in the test, showing 104.4 decibels at 90mph. The Revolution is one of two fl ip-front helmets in our test and it has an aerodynamically ‘dirtier’ shape than many of the others. It’s also the heaviest helmet on test. The RiDE winner recorded a lower decibel level at 90mph than the Lazer at 60mph, which shows the big difference in noise levels between the top and bottom scoring helmets in our test.■ At 60mph – 95.2dB ■ At 70mph – 97.4dB■ At 80mph – 101.5dB■ At 90mph – 104.4dB■ Average – 99.6dB

■ Weight 1775g■ Contact: 01623 757262

After his speed runs, our test rider commented that the amount of noise he experienced in this helmet was uncomfortable. The decibel readings appear to back up this feeling. The average reading for the four different speeds was just over 97dB. Like the two helmets immediately below it in the noise stakes, this budget RST lid has a venturi over the top of the shell, though it’s impossible to say whether this alone is the cause of the high noise readings.■ At 60mph – 93.1dB ■ At 70mph – 96.2dB■ At 80mph – 98.8dB■ At 90mph – 100.7dB■ Average – 97.2dB

■ Weight 1473g■ Contact: 01623 757262

The aggressive-looking AGV takes a basement fi nish for an average of 97.9dB across our tests at four different speeds. Again, we could have worn the test-winning lid at 90mph and experienced less noise than wearing this one at 60mph. It steadily increased, by three decibels each time, as we raised the speed from 60mph through to 90. This is another lid with a venturi on the crown of the shell, in common with other noisy helmets.■ At 60mph – 93.2dB ■ At 70mph – 96.2dB■ At 80mph – 99.8dB■ At 90mph – 102.4dB■ Average – 97.9dB

■ Weight 1481g■ Contact: 01623 757262

Lazer Revolution £140 OGK Aeroblade £180

AGV Stealth £190 RST Cobravent £70

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One of three helmets to average 95.5dB across our four speed runs and it’s another with a smoother shape across the top of the shell. It was noisier at 90mph than the other two helmets that fi nished with the same average sound reading, just breaking through the 100dB mark on our fastest run.■ At 60mph – 90.5dB ■ At 70mph – 94.2dB■ At 80mph – 97.1dB■ At 90mph – 100.1dB■ Average – 95.5dB

■ Weight 1401g■ Contact: 01425 620580

The Caberg ends up fractionally quieter than the Suomy, mainly thanks to a lower peak decibel fi gure of 101.4 at 90mph. Its average recording was 96.6dB across the speed runs. Once again, there is a venturi over the top of the shell. The lid, which comes with a built-in fl ip-down dark visor, was relatively noisy in all our four speed runs, hence the low fi nishing position.■ At 60mph – 92.0dB ■ At 70mph – 94.2dB■ At 80mph – 98.8dB■ At 90mph – 101.4dB■ Average – 96.6dB

■ Weight 1510g■ Contact: 01933 418414

Suomy’s race replica is not quite as loud as the paint scheme that adorns the Spec-1R submitted for our test. But it’s still towards the bottom end of the 18 lids on test, with an average decibel count of 96.8dB. Once again, there is an air-scoop on the crown of the lid. ■ At 60mph – 90.9dB ■ At 70mph – 95.6dB■ At 80mph – 98.3dB■ At 90mph – 102.4dB■ Average – 96.8dB

■ Weight 1440g■ Contact: 01933 410272

Suomy Spec-1R £250 Caberg V2 £100

X-Lite X801R £22010th= 10th

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The Raid II won RiDE’s more general helmet test last year, when we conducted impact testing and strap strength checks. But it doesn’t fare so well in our noise test, with only an average performance. The lightest full-face lid on test has a smoother profi le across the top than the lids behind it in the fi nishing order. The average sound reading was 95.5dB and it is the fi rst helmet of the 18 to register under 100 decibels at 90mph, sneaking in with 99.8dB.■ At 60mph – 91.9dB ■ At 70mph – 93.3dB■ At 80mph – 97.2dB■ At 90mph – 99.8dB■ Average – 95.5dB

■ Weight 1375g■ Contact: 01384 413841

Shoei Raid II £205

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This is a respectable performance from the Korean-made KBC, which just edges over 95dB on average across the four runs at differing speeds. The 60mph reading is the fi rst to duck under the 90dB barrier and the 90mph fi gure is a shade under 100dB.■ At 60mph – 89.6dB ■ At 70mph – 93.3dB■ At 80mph – 98.1dB■ At 90mph – 99.6dB■ Average – 95.2dB

■ Weight 1633g■ Contact: 01283 763120

The cheapest helmet on our test takes a creditable fi nish in seventh place, with an average sound fi gure of 94.3dB. It compares well with its competition in all four of our speed runs, despite the £50 price tag. Like the helmets around it in the fi nishing order, it has a smooth shell shape rather than a scoop vent on top.■ At 60mph – 88.9dB ■ At 70mph – 92.9dB■ At 80mph – 95.9dB■ At 90mph – 99.7dB■ Average – 94.3dB

■ Weight 1603g■ Contact: 01768 483784

We tested this open-faced lid, aimed at the classic enthusiast, because we’ve found it quiet in general road use. And the fi gures seem to back us up, with a reasonable performance in our test (we wore goggles). It averaged under 95dB and peaked at less than 100dB. One theory for the good performance is the lack of a cavity between chin and chinbar for wind to whirl around. Unsurprisingly, this was the lightest lid on test.■ At 60mph – 89.2dB ■ At 70mph – 92.7dB■ At 80mph – 96.6dB■ At 90mph – 99.8dB■ Average – 94.6dB

■ Weight 1341g■ Contact: www.davida.co.uk

This was another good performer from our more general helmet test in 2005, scoring the same number of points as the Shoei Raid II. It’s a reasonable performer in our noise test, registering an average of 95.5dB and peaking at 98.5dB at 90mph. Like the Shoei, the HJC has a smoother shape over the top than the lids further down the fi nishing order.■ At 60mph – 92.2dB ■ At 70mph – 95.3dB■ At 80mph – 96.1dB■ At 90mph – 98.5dB■ Average – 95.5dB

■ Weight 1428g■ Contact: 0870 990 9620

KBC VR2 £160HJC AC11 £200

Davida Classic Jet £168 Nitro N510V £50

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KIT TESTKIT TEST

106 RIDE APRIL 2006

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The results of this test support RiDE readers’ experiences of the Roof helmet. They rated it highly in relation to wind noise in RiDER Power 2005 and it scores a top three in this test. It is consistently quieter than its rivals, averaging just under

Experience on the road suggests Arai’s Corsair model is noisier than its Astro-R sibling, but the fi gures don’t back that up. The most expensive helmet on test is also the only one featuring a venturi on top that isn’t towards the bottom of our

5th

test. One possible theory is that the noise heard in a Corsair is irritating, but not loud enough to be a worry to your hearing. It averaged 92.4dB and was quieter than the Astro-R at all four test speeds.■ At 60mph – 86.6dB ■ At 70mph – 90.3dB■ At 80mph – 94.6dB■ At 90mph – 97.9dB■ Average – 92.3dB

■ Weight 1482g■ Contact: 01782 569800

91dB across all runs and staying well under the 100dB mark on every test. ■ At 60mph – 86.1dB ■ At 70mph – 89.8dB■ At 80mph – 92.2dB■ At 90mph – 95.5dB■ Average – 90.9dB

■ Weight 1483g■ Contact: 01923 772273

Nolan claim to have made an effort to reduce noise in the N84 by adding padding to the ear cavities. The results of our test suggest it may have worked. It’s one of the star performers, averaging 91dB at the four speeds and being a particularly

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The fi rst of two consecutive Arais in our fi nishing order, with a good result for the popular Astro-R. It was slightly above the 100dB marker at 90mph, but the other readings were all low enough to put the lid in the top six with an average of

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94.2dB. This has the classic, smooth shape with no large vents to disrupt airfl ow over the shell.■ At 60mph – 89.0dB ■ At 70mph – 92.3dB■ At 80mph – 95.5dB■ At 90mph – 100.1dB■ Average – 94.2dB

■ Weight 1475g■ Contact: 01782 569800

Arai Astro-R £330 Arai Corsair £450

Nolan N84 £130 Roof R010 £195

good performer at 90mph, registering 96.5dB. There’s an external, fl ipdown sunshield and we found it did not affect noise if we changed its position.■ At 60mph – 86.7dB ■ At 70mph – 89.2dB■ At 80mph – 91.6dB■ At 90mph – 96.5dB■ Average – 91.0dB

■ Weight 1620g■ Contact: 01425 620580

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Schuberth put their lids in for lots of wind tunnel testing, which shows its worth in our test. The tester commented on how quiet the lid was as soon as he’d fi nished the speed runs, and the fi gures show he was right. The average was under 90db and even the 90mph runs were by far the quietest on test. At 90mph in the Schuberth, our tester was exposed to lower noise levels than experienced at 60mph while wearing any of the bottom four helmets. A snug fi t around the neck and a close-fi tting chin curtain could explain the impressive performance.■ At 60mph – 82.3dB ■ At 70mph – 86.2dB■ At 80mph – 88.8dB■ At 90mph – 91.5dB■ Average – 87.2dB

■ Weight 1577g■ Contact: 01425 620580

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This proves that fl ip-up helmets don’t have to be noisy. The System 5 is made for BMW by Schuberth, who pride themselves in keeping their German riders happy with quiet lids. It did well in all four runs at differing speeds, averaging a smidge over 90dB for a second place fi nish.■ At 60mph – 84.4dB ■ At 70mph – 87.9dB■ At 80mph – 92.3dB■ At 90mph – 96.2dB■ Average – 90.2dB

■ Weight 1753g■ Contact: 0800 777155

THERE are a huge number of factors that contribute to what makes a helmet noisy or quiet, and not all of them can be controlled by the manufacturer. The bike you ride, the way you ride it and the shape of your head are all important.

During our test, we carried out control experiments on a selection of helmets by changing the rider, then changing the bike, and fi nally changing both.

The changes had such an effect on the readings that we have based our

fi ndings purely on the unfaired bike with the same rider on board.

We are confi dent our test has separated the quiet lids from the noisy, but with so many variables we can’t promise the result will be the same with a given helmet on a given bike.

So we come back to one of RiDE’s favourite topics – earplugs. We recommend they are used if you experience intrusive wind noise, especially if covering longer distances.

Even in the quietest of our tested helmets, our man was exposed to enough noise at 70mph for possible hearing damage if continued over long distances. Factory workers are advised to wear hearing protection if they are exposed to 85dB for eight hours a day.

And noise levels grow rapidly. Expose yourself to 90dB for eight hours and you risk hearing damage. Take that up to 93dB and you risk hearing damage within four hours. Every extra three decibels halves the

time before risking damage.So at 105dB, roughly the noisiest

recording in our test, you can ride for just 15 minutes before putting your hearing in jeopardy.

Earplugs will take away 5-10dB so the best combination is to wear a quiet helmet and use earplugs.

On this occasion, we have not awarded any of our coveted RiDE triangles. This is because it isn’t an all-encompassing test and purely focuses on the noise issue, which we know is important to you.

Sounding off

BMW System 5 £280

Schuberth S1 £350

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Documents

The sound of silencepds1.egloos.com/pds/200812/24/32/helmet-silence.pdf · 2008. 12. 23. · The sound of silence A noisy helmet can ruin not only your day, but your hearing. RiDE