Saturday, 23 August 2008

How to Keep Biking Down to a Sweet Roar

Keen bikers might shake their heads in disbelief, but I've been guilty of denial and procrastination over this since Jan '02, when I began blasting out along the M1 to Watford every weekday on an 1150GS. Boy does that wind howl in your ears at... ahem... 70mph.

Ear plugs seemed an obvious solution. But the little yellow foam ones had a habit of popping out en route. So I took myself down to Ultimate Ear within a few short weeks and got some custom-fitted silicone ones like rock musicians had begun to wear. They take out the high frequency stuff, but allow you to hear that some jerk has crept into your blindspot before it's too late.

But even with industrial-deafness averted, I still wanted to kill a bit more of that wind noise.

I threw money at the problem and got a larger, adjustable "Adventure" screen fitted to my GS. But when I traded that bike for a twin-spark version in late '03, I wasn't sufficiently persuaded by the results to transfer the larger screen to the new GS. My commute to Watford ended in early '04, so I stopped searching. But after 8,000 miles of pootling around West London I'm now commuting along the M4. Having taken a fresh look at wind noise reduction, I thought it might be helpful to share the results...

The science is important, of course, and Mike Lower and a team from the Institute of Sound and Vibration Research has found that even riders with enormous windscreens adopt unhelpful preferred riding positions from a wind noise standpoint - mainly because the windscreens can't be kept clean and clear enough to look through. So, on any motorcycle travelling more than 35mph:

"The main noise source was the turbulent flow from the top of the windscreen. The turbulence hits the helmet at a position somewhere between the neck or the top of the visor depending upon the windscreen's height. This position determines whether improvements to the sealing round the neck or improvements to the visor and its sealing and hinges will be more effective at reducing noise. Noise reductions up to 8 dB were achieved by simple helmet modifications or treatments. The lowest levels at the ear were obtained under earplugs and under a flying helmet containing earmuffs with active noise reduction."
While I'm just over 6'4" and my head seems way above the standard 1150 GS screen, the wind off the top actually only strikes the top of my visor. But it's the wind that hits my shoulders from the sides of the screen that seems to be worst, and that may be getting under the helmet to cause some of the noise. So how to keep it out?

An article on Webbikeworld recommended the Windjammer II as the best and longest wearing means of sealing the gap around your neck (though in winter the "elephant's foreskin" must help). But a comment on the article from a fellow Shoei helmet owner suggested that the Windjammer may not be that well adapted to Shoei's, and recommended the Shoei "chin curtain" at £7.99. I promptly ordered one. Fitting it to my XR900 was less than intuitive (don't be afraid to wedge the middle plastic "tongue" and the plastic "skirt" between helmet and helmet lining), but it has definitely cut the wind noise to some degree. It also raises the threshold at which the wind becomes louder than the engine to about 50mph instead of 35mph.

Meanwhile, I've also investigated the after-market in windscreens that are wider as well as a bit taller than the one I have. BMW will sell me an Adventure screen for about £196, including the screen blocks, but it's only about an inch larger all round, and didn't seem to make enough of a difference in the past. An MRA "Vario" will set me back about £106. Discussion forums talk about additional "winglets", but it's not all that clear that these are necessary. The rather fulsome X-tall Aeroflow will set me back £390, since it has to come from the US, via a French distributor. Finally, Cee Bailey of the US will send their biggest screen for about £240, just under half of which is for the shipping.

I've since ordered and fitted the MRA Vario, having seen generally good comments around the web, and discussed the why's and wherefor's briefly with Giles at HPS, the UK distributors.

I considered a here's-me-hands-free-on-the-M4-"Jackass"-style video clip for proof, but have contented myself with a shot of the the MRA Vario screen from HPS, in situ.

At last, I can hear that flat-twin Boxer at speed, instead of the wind.

Job done!
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