Turbulent Thinking

Wind Disturbance


I read on the Net that turbulence around the helmet can be caused not by the air being directed around the screen, but being sucked up the gap in the fairing where the forks sit. It makes sense that forcing air up and over the riding space will cause negative air pressure immediately behind the screen, and that this will draw air into it.

I've watched rain drops fall from the top of the Vario screen and then, just above the tank, suddenly defy gravity and fly upward toward my face at the speed of travel. It gives some explanation?

Perhaps then the helmet is not at fault, nor directly the screens, but my sitting position may be too close to the tank inviting disturbance from this internal (and underhand) air flow. It may also explain why wind direction and strength can have such affect where a cross wind may help to dampen the affect from the side of the screen, but from head on? It's just going to exacerbate it.

Hey, this is only theory based on some writings on a page about wind noise about the helmet, but who knows?

Wind Muff


I popped in to the bike shop in North Camp expressly to buy a "Wind Blocker" to see if, by smoothing out the wind flow around the seems between the pads at the base of the helmet, and jamming up the airflow into the helmet from its bottom end (cuased by the negative pressure caused in the helmet by its ventilation through inlets and exhausts) I could negate the high-frequency vibration.



Once fitted I had my doubts. It doesn't fully enclose the neck so air will still enter the helmet from beneath, but it does present on plain across the lower edge where all the padding interacts with the airflow. I can't claim it worked miracles, but with ear defenders it had the following effects:
    Lower turbulence noise
    Attention drawn to the noise created at the visor edges
    Sweaty where the neoprene contacts the skin

Sadly, on entering Fareham air space and needing to rotate my head like an owl to watch what the plonkers in cars were up to, and having being quite hot and so earlier having discarded my buff and opened the velcro on my jacket, the velcro gripped the Wind Blocker and ripped it from its seat on the helmet giving me a black Blackadder rough as I pulled in for fuel.

The helmet's matt black finish probably didn't give as good a friction tot he glue-less neoprene seal in any case.

I tried it again this morning but it slipped off the nape of the helmet - again on conducting all-round observations on the Fareham roundabouts where movement of my neck contacted the edge of the neoprene and caught it sufficiently to snag it off its seat.

At that point, rather hot and bothered by a late start anyway, I pulled over and removed the cuff. It's now in one of Dilbert's glove boxes out there in a tropical storm's worth of rain tonight. I'll retrieve it tomorrow. Boy, I wish I'd covered Dilbert - the forecast showed us missing the showers all together. Sometimes the South coast can let us down but, hey, it's gotta be grim up North tonight?

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