Sibbo wrote:
I was just out for a ride and tested Charlies solution, it worked ! Very strange! I put my gloved hand to various parts of my helmet, on the left side only and got complete silence touching some places but little difference in others.
I wonder if it somehow changes the turbulence around the helmet or dampens resonations ? Either way it works so I think I'll try Charlie's idea of taping on a few bits of foam to try to change the air flow .
Sibbo, I'm now thinking that it's the hole under the helmet (where you stick your face) that causes the problem, and the act of putting your hand up beside the helmet is affecting the turbulence. It'd be easy to test, if we just had a hand without a life-support system attached.
Something I've noticed recently is that if I wear a balaclava under the helmet, the noise is a lot louder. I think this is because the balaclava is stretched over the ears and is making a mechanical connection that amplifies the sound.
I wonder if a thick scarf wrapped around the neck would make a difference. Some helmets (eg BMW) come with sound attenuating devices - panels that clip in around the neck and block off the unruly turbulence.
Charlie
and Brunhilde - 1974 R90/6
Graduate, Wallace and Gromit School of Engineering and Design (Pending)