New wheels - odd sound

Rich-hill
Rich-hill Posts: 75
edited September 2014 in Workshop
HI All,

I bought some Cosmic Carbone SLS wheels yesterday and fitted them this morning ready for a sportive tomorrow.

I found that when standing and pedalling i could hear what sounded like the rear wheel rubbing on my pads. I proceeded to loosen the pads off so they were further from the wheel (apron 8mm each side)

Since doing this the sound persists, so i'm guessing it can't be the pads. Should these wheels make this sound, or could they be rubbing on something else? There is some lateral flex in the rim, i can push it with my hands either way. Is this normal?

when riding normally i don't get this sound at all, i can't feel any play anywhere either.

Many Thanks

Comments

  • Rich-hill
    Rich-hill Posts: 75
    th_IMG_1865_zps7b9996b7.mp4
  • keezx
    keezx Posts: 1,322
    Could be the "natural sound"of these wheels.
    The larger the volume of the rim, the more it works as a sound box.
  • plodder73
    plodder73 Posts: 326
    There are more qualified people than me on here, but to my eye that movement does not look right at all.
  • g00se
    g00se Posts: 2,221
    That doesn't look right at all.
  • ugo.santalucia
    ugo.santalucia Posts: 28,312
    g00se wrote:
    That doesn't look right at all.

    It's an aluminium rim with 20 spokes, what do you expect... with enough force you can bend it laterally by a few mm. What the OP experiences seems more the classic sound that big hollow rims make when rocked side to side
    left the forum March 2023
  • ai_1
    ai_1 Posts: 3,060
    My bike came with Mavic Ksyrium Elites and for the first few rides every time I got out of the saddle to push up a short hill or to sprint I got a worrying buzzy/scrapey/ rattley sound from the back wheel. I thought maybe the rim was scraping on the brake pads and opened the calipers to check - no improvement. I thought maybe it was the "dork disk" that came supplied on the wheels. I removed it - seemed like a slight improvment but not much. Then I inspected the spokes. The wheels have aero spokes and they don't touch where they cross over, there's a gap of a few millimeters. However one of the spokes was rotated about 45 degrees so it wasn't inline with the direction of travel. This also meant it was much closer to the adjacent spoke that crossed beside it (maybe only 1mm gap). I rotated the spoke back into alignment and the sound vanished. I presume a little flex when I applied power out of the saddle was enough for the spokes to come into contact and cause the noise.

    All sorted now but drove me nuts on the first few rides.

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