vibration in fork/wheel?

rowlers
rowlers Posts: 1,614
edited August 2012 in Workshop
I've got some back/forward movement, vibration going in the front of the bike under heavy breaking. You can see the fork shuddering back and forth.....
Ribble GF with Intrepid wheelset and Chinese carbon fork.
It only appeared when the wheels and fork were fitted.
So, I was thinking the QR could be loose so tightened it and swapped it for another, this hasn't helped. I've checked the headset and can't find any play, but give it a tweak anyway. I've checked the wheel and it is as true as it can be to my eye on my stand. Could It be wheel flex?

Next think I'm going to try is another wheel.
And finally I'll put the old fork back on.

Is there anything obvious that I've missed that could explain this away?


Cheers

Comments

  • sungod
    sungod Posts: 17,536
    maybe it's brake judder, check rims are clean, try toeing-in the front of the brake pads slightly, about 0.5-1mm
    my bike - faster than god's and twice as shiny
  • rowlers
    rowlers Posts: 1,614
    sungod wrote:
    maybe it's brake judder, check rims are clean, try toeing-in the front of the brake pads slightly, about 0.5-1mm
    i knew I'd miss something simple to check!

    Thanks
  • Wirral_paul
    Wirral_paul Posts: 2,476
    Check the headset also (pull the front brake on hard, and rock the bike back and forward. You'll feel any free play quite easily)
  • rowlers
    rowlers Posts: 1,614
    Thanks. Already tested headset can't feel any play.
    I'm just hoping its not a faulty fork.
  • rowlers
    rowlers Posts: 1,614
    So, I've cleaned rims and pads (also tried different pads), toe the pads in slightly and whilst the judder isn't quite so bad it is still there.
    I've had the fork out and all looks OK, headset is all good as far as I can tell - there is zero play that I can feel/see.
    I'm not 100% happy with the QR, so I'm going to try a Shimano one from my MTB.
    Any thing else i can check - it driving me mad lol!
  • Wirral_paul
    Wirral_paul Posts: 2,476
    Is the front wheel perfectly true? Tighten up the clearance of the brake blocks until they barely clear and spin the wheel to check
  • rowlers
    rowlers Posts: 1,614
    Is the front wheel perfectly true? Tighten up the clearance of the brake blocks until they barely clear and spin the wheel to check

    Fairly certain its true. I'll check again on my truing stand.

    couple of pics of headset:
    20120807_190137.jpg

    The looks like a gap between bearing and crown race but it sits squarely
    20120807_191752.jpg
    gap between steerer tube on fork crown, prob 1mm, but there is ZERO play...

    This is the headset as supplied by ribble with the frame.
  • I had this just 3 weeks ago. Took the headset, cleaned and replaced it - but was still there but crown race looked a little wonky, or maybe it was just me looking for a reason, so I took it to the LBS who fitted a new headset - and heres the thing - when I got it back the skewers were much tighter than I do them - so I dont know whether teh vibration was play in the headset or slightly loose skewers. Might be worth checking that at least.
    The dissenter is every human being at those moments of his life when he resigns
    momentarily from the herd and thinks for himself.
  • rowlers
    rowlers Posts: 1,614
    I had this just 3 weeks ago. Took the headset, cleaned and replaced it - but was still there but crown race looked a little wonky, or maybe it was just me looking for a reason, so I took it to the LBS who fitted a new headset - and heres the thing - when I got it back the skewers were much tighter than I do them - so I dont know whether teh vibration was play in the headset or slightly loose skewers. Might be worth checking that at least.
    I'll give the QR a good nip up. I've got a cheapo ebay Ti skewer, looks nice, is light, but doesn't feel tight. So I'll try my trusty Shimano XT, see how it goes and buy some decent skewers...