Clunk

Discussion in 'Australia and New Zealand' started by gumby, Feb 23, 2006.

  1. gumby

    gumby Guest

    Gday peeps
    My ride, an orbea vento running campag veloce has turned one, done
    about 5500kays of training and riding on this bike. I have regular
    cleaned and lubed the chain during this time.
    Question. I have bought a set of campag eurus wheels with a 12-25
    chorus cassette. I have done about 250kays of racing and tt's on this
    set. Everytime I race on the eurus when I freewheel and then put power
    on, without fail I get a huge metallic clunk through the frame, doesnt
    happen with the campag vento wheels (veloce).
    Now DeF who is a bike bling addict from way back suggests the chain is
    stretched and the veloce cassette has worn with it too, I use mainly
    the 19 and 17 cogs. I thought it may have been the LBS not locking the
    lockring down tight enough on the chorus.
    Is he likely to be right, and should I just get a new chain and keep
    the veloce cassette?
    Steven
     
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  2. BrettS

    BrettS Guest

    gumby wrote:
    > Gday peeps
    > My ride, an orbea vento running campag veloce has turned one, done
    > about 5500kays of training and riding on this bike. I have regular
    > cleaned and lubed the chain during this time.
    > Question. I have bought a set of campag eurus wheels with a 12-25
    > chorus cassette. I have done about 250kays of racing and tt's on this
    > set. Everytime I race on the eurus when I freewheel and then put power
    > on, without fail I get a huge metallic clunk through the frame, doesnt
    > happen with the campag vento wheels (veloce).
    > Now DeF who is a bike bling addict from way back suggests the chain is
    > stretched and the veloce cassette has worn with it too, I use mainly
    > the 19 and 17 cogs. I thought it may have been the LBS not locking the
    > lockring down tight enough on the chorus.
    > Is he likely to be right, and should I just get a new chain and keep
    > the veloce cassette?
    > Steven
    >


    I had the same issue and it turned out to be a weak return spring on the
    freewheel ratchet. Because the spring wasn't returning the ratchet
    pawls back out fully, the ratchet would only engage on the tip of the
    teeth and when I powered back on, the pressure would force the pawls
    fully outwards, smacking against the bottom of the teeth inside the hub.
    This would cause an almighty clunk that really concerned me until the
    LBS replaced the spring. This happened when the bike was fairly new, so
    it seems to be a 'burn in' issue. Funnily enough, it started just after
    my first Kings Park TT with about the same mileage on it as your wheels.

    Of course, your chain may well be worn, but if it was worn enough to
    cause a clunk, it would be due to jumping teeth which would happen all
    the time while you accelerate, not just the once after you stop
    freewheeling and power on.

    --
    BrettS
     
  3. vesel

    vesel Guest

    "BrettS" <[email protected]> wrote in message
    news:[email protected]
    > gumby wrote:
    >> Gday peeps
    >> My ride, an orbea vento running campag veloce has turned one, done
    >> about 5500kays of training and riding on this bike. I have regular
    >> cleaned and lubed the chain during this time.
    >> Question. I have bought a set of campag eurus wheels with a 12-25
    >> chorus cassette. I have done about 250kays of racing and tt's on this
    >> set. Everytime I race on the eurus when I freewheel and then put power
    >> on, without fail I get a huge metallic clunk through the frame, doesnt
    >> happen with the campag vento wheels (veloce).
    >> Now DeF who is a bike bling addict from way back suggests the chain is
    >> stretched and the veloce cassette has worn with it too, I use mainly
    >> the 19 and 17 cogs. I thought it may have been the LBS not locking the
    >> lockring down tight enough on the chorus.
    >> Is he likely to be right, and should I just get a new chain and keep
    >> the veloce cassette?
    >> Steven
    >>

    >
    > I had the same issue and it turned out to be a weak return spring on the
    > freewheel ratchet. Because the spring wasn't returning the ratchet pawls
    > back out fully, the ratchet would only engage on the tip of the teeth and
    > when I powered back on, the pressure would force the pawls fully outwards,
    > smacking against the bottom of the teeth inside the hub. This would cause
    > an almighty clunk that really concerned me until the LBS replaced the
    > spring. This happened when the bike was fairly new, so it seems to be a
    > 'burn in' issue. Funnily enough, it started just after my first Kings
    > Park TT with about the same mileage on it as your wheels.
    >
    > Of course, your chain may well be worn, but if it was worn enough to cause
    > a clunk, it would be due to jumping teeth which would happen all the time
    > while you accelerate, not just the once after you stop freewheeling and
    > power on.
    >
    > --
    > BrettS


    Swap the cassettes over and see if the problem follows the cassette or the
    wheel.

    Peter
     
  4. Gumby

    Gumby Guest

    vesel wrote:
    > "BrettS" <[email protected]> wrote in message
    > news:[email protected]
    >
    >>gumby wrote:
    >>
    >>>Gday peeps
    >>>My ride, an orbea vento running campag veloce has turned one, done
    >>>about 5500kays of training and riding on this bike. I have regular
    >>>cleaned and lubed the chain during this time.
    >>>Question. I have bought a set of campag eurus wheels with a 12-25
    >>>chorus cassette. I have done about 250kays of racing and tt's on this
    >>>set. Everytime I race on the eurus when I freewheel and then put power
    >>>on, without fail I get a huge metallic clunk through the frame, doesnt
    >>>happen with the campag vento wheels (veloce).
    >>>Now DeF who is a bike bling addict from way back suggests the chain is
    >>>stretched and the veloce cassette has worn with it too, I use mainly
    >>>the 19 and 17 cogs. I thought it may have been the LBS not locking the
    >>>lockring down tight enough on the chorus.
    >>>Is he likely to be right, and should I just get a new chain and keep
    >>>the veloce cassette?
    >>>Steven
    >>>

    >>
    >>I had the same issue and it turned out to be a weak return spring on the
    >>freewheel ratchet. Because the spring wasn't returning the ratchet pawls
    >>back out fully, the ratchet would only engage on the tip of the teeth and
    >>when I powered back on, the pressure would force the pawls fully outwards,
    >>smacking against the bottom of the teeth inside the hub. This would cause
    >>an almighty clunk that really concerned me until the LBS replaced the
    >>spring. This happened when the bike was fairly new, so it seems to be a
    >>'burn in' issue. Funnily enough, it started just after my first Kings
    >>Park TT with about the same mileage on it as your wheels.
    >>
    >>Of course, your chain may well be worn, but if it was worn enough to cause
    >>a clunk, it would be due to jumping teeth which would happen all the time
    >>while you accelerate, not just the once after you stop freewheeling and
    >>power on.
    >>
    >>--
    >>BrettS

    >
    >
    > Swap the cassettes over and see if the problem follows the cassette or the
    > wheel.
    >
    > Peter
    >
    >

    Thanks for responses.
    I am going to go with Brett S and the ratchet pawls diagnosis.
    Reason, put the eurus on on Sunday and apart from the bloody awful
    creaking from around the bottom bracket, the 'clunk' has gone. Though
    there wasnt a lot of freewheeling going on on Sunday morning. Wangara is
    a different course to Kewdale innit?

    Eurus now done a definate 260km. Burnt in? It was warm that for sure.
    Steven
     
  5. BrettS

    BrettS Guest

    Gumby wrote:
    >
    > Thanks for responses.
    > I am going to go with Brett S and the ratchet pawls diagnosis.
    > Reason, put the eurus on on Sunday and apart from the bloody awful
    > creaking from around the bottom bracket, the 'clunk' has gone. Though
    > there wasnt a lot of freewheeling going on on Sunday morning. Wangara is
    > a different course to Kewdale innit?


    Ah, yes. Did you go faster up the hill than down it?

    --
    BrettS
     
  6. DeF

    DeF Guest

    BrettS wrote:
    > Gumby wrote:
    >>
    >> Thanks for responses.
    >> I am going to go with Brett S and the ratchet pawls diagnosis.
    >> Reason, put the eurus on on Sunday and apart from the bloody awful
    >> creaking from around the bottom bracket, the 'clunk' has gone. Though
    >> there wasnt a lot of freewheeling going on on Sunday morning. Wangara
    >> is a different course to Kewdale innit?

    >
    > Ah, yes. Did you go faster up the hill than down it?
    >
    > --
    > BrettS


    Gumby forgot to mention how he went in that race. From his
    three starts in C-grade with the vets he's come 5th, 2nd and
    now 1st so well done him! The handicapper has his eye on him.

    DeF

    --
    e-mail: [email protected]
    To reply, you'll have to remove finger.
     
  7. gumby

    gumby Guest

    Yes well Thanks for that DeF! I am now going to do a couple of TT's
    and stay away from the crits, I am a bit like a greyhound after the
    rabbit in those things. Not sure I want to be in B grade at this stage
    of the season.
     
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