Hey all, Im pretty sure the answer is here! This is my first zipp wheelset so i am new to the brand, theres a sound coming from the rear hub, very difficult to explain so i put it on youtube. Its the whistling sound in the background and can't be heard while riding. I know the video shows it being spun fast but it also happens when its much slower.

Thanks for the help!!

http://www.youtube.com/watch?v=m0lzoM0aYY0

Sounds like harmonic resonance likely related to specific spoke tension and alignment. Of course when you are on the bike the wheel is loaded and the acoustic properties are altered. There is nothing wrong with your wheel (other than it is not a tubular).

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i believe ive heard it with every 188 rear hub since they came out. dont know the exact cause, but ive never heard it while riding. my guess would be spoke harmonics caused by the frequency of the pawls/ratchet. as mr.gib said, loading the wheel would alter the frequency of the spokes.
it's normal.

normal

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charles@pezcyclingnews.com

Sounds like a wheel spinning to me. Nothing unusual.

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My C59 http://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=80193

thanks a lot fellas, i'll sleep better now!

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Dogma 6650g

my 202s make the same sound. the first time i heard it i thought it was my cellphone...