Wibbly wobbly weirdness

lost_in_thought
lost_in_thought Posts: 10,563
edited June 2009 in Commuting chat
OK, so.

On the tifosi, when cornering, I keep getting the slightly perturbing feeling that the bike is just about to disappear from underneath me and head off sliding down the road.

It actually feels like the rear tyre is rolling off and the rim is hitting the road.

Now, I thought that the problem might be low tyre pressure, so pumped the tyres up to 120PSI (max on the side wall is 130) and still had the same problem.

I also checked the wheel (to the extent of my minimal knowledge) and no loose spokes, no irregularities that I could find.

Any suggestions? The wheels are Khamsins, the tyres are 'Vredestein Ricorso 700x23c'...
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Comments

  • always_tyred
    always_tyred Posts: 4,965
    Check the wheel nuts. :wink:
  • lost_in_thought
    lost_in_thought Posts: 10,563
    Check the wheel nuts. :wink:

    :lol:

    I did... but good shout!
  • gtvlusso
    gtvlusso Posts: 5,112
    Is the feeling from the front or back?

    If it is front - check the fork for stiffness, especially carbon forks....no cracks and so on. Make sure any QR skewers are well done up and the wheel is lokcing place - spin the wheel and see in the bearings grind or the wheel moves about wheilst locked in place.

    For the back end. Check for craks in the frame welds/joins. Check the QR skewer is well done up and clamping the wheel in place. Check wheel bearings as with front.

    Check you seatpost and seat are fixed on nice and tight (has happened to me before now that I though the bike was "vague" - turned out I had a loose seat!

    Check your clamp bolts on the stem and bars too! Nice and tight!

    Get the wheels trued - or just checkl the run straight'ish by eyesight.

    Ummmmm......errr....
  • jonginge
    jonginge Posts: 5,945
    Loose cones? Any play in the bearings?
    FCN 2-4 "Shut up legs", Jens Voigt
    Planet-x Scott
    Rides
  • always_tyred
    always_tyred Posts: 4,965
    Remove all the spokey dokeys.
  • have a look at the hub. some of the nuts in the assembly may have come loose over time or may not have be tightened correctly
    The doctor said I needed to start drinking more whiskey. Also, I’m calling myself ‘the doctor’ now
  • el_presidente
    el_presidente Posts: 1,963
    don't ride while pissed
    <a>road</a>
  • lost_in_thought
    lost_in_thought Posts: 10,563
    From the back...

    The wheel appears to be true, checked the skewer was holding it in place, will check the seat...

    No idea how to check the bearings though, and don't really know what a cone is!
  • Gazzaputt
    Gazzaputt Posts: 3,227
    If it's a carbon check it over carefully especially around the BB area.
  • jonginge
    jonginge Posts: 5,945
    From the back...

    The wheel appears to be true, checked the skewer was holding it in place, will check the seat...

    No idea how to check the bearings though, and don't really know what a cone is!
    Grab the frame, grab the wheel rim and give it a bit of lateral welly. Does it move?

    Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them
    FCN 2-4 "Shut up legs", Jens Voigt
    Planet-x Scott
    Rides
  • Feltup
    Feltup Posts: 1,340
    Are you pedalling when this happens or in extreme cornering mode with the outside foot planted at the bottom of the stroke?
    Short hairy legged roadie FCN 4 or 5 in my baggies.

    Felt F55 - 2007
    Specialized Singlecross - 2008
    Marin Rift Zone - 1998
    Peugeot Tourmalet - 1983 - taken more hits than Mohammed Ali
  • jeepie
    jeepie Posts: 497
    Think JonGinge is on the money as this is what I had recently. It felt just as Lit describes.
  • lost_in_thought
    lost_in_thought Posts: 10,563
    Feltup wrote:
    Are you pedalling when this happens or in extreme cornering mode with the outside foot planted at the bottom of the stroke?

    Both - I tried pedalling and the other method to see if it made a difference...
  • jonginge
    jonginge Posts: 5,945
    Jeepie wrote:
    Think JonGinge is on the money as this is what I had recently. It felt just as Lit describes.
    :D Been there, done that, broke the axle :(
    FCN 2-4 "Shut up legs", Jens Voigt
    Planet-x Scott
    Rides
  • Does it feel a bit 'gyroscopic'? I had that on one of my bikes after I put a new set of tyres on it.

    IIRC it was on the front though.
  • fossyant
    fossyant Posts: 2,549
    Crap tyres probably..........
  • lost_in_thought
    lost_in_thought Posts: 10,563
    Does it feel a bit 'gyroscopic'? I had that on one of my bikes after I put a new set of tyres on it.

    IIRC it was on the front though.

    Not really... just slippy and unstable...
  • lost_in_thought
    lost_in_thought Posts: 10,563
    fossyant wrote:
    Crap tyres probably..........

    Hmmm, I did wonder...
  • Bassjunkieuk
    Bassjunkieuk Posts: 4,232
    I'd be interested to see how this pans out as I'm sure I was getting something similar the other day but I just put it down to improper technique as I'm still getting used to the faster downhill cornering on my roadie!
    Who's the daddy?
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  • Greg T
    Greg T Posts: 3,266
    It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.

    I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.

    I reckon your spoke tensions off and you need to get them tightened.

    or some new mavics.


    NEW STUFF!!!!
    Fixed gear for wet weather / hairy roadie for posing in the sun.

    What would Thora Hurd do?
  • Bassjunkieuk
    Bassjunkieuk Posts: 4,232
    Greg T wrote:
    It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.

    I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.

    I reckon your spoke tensions off and you need to get them tightened.

    or some new mavics.


    NEW STUFF!!!!

    +1 All the best SCRer's use em...........;-)
    Who's the daddy?
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    Player of THE GAME
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  • greg66_tri_v2.0
    greg66_tri_v2.0 Posts: 7,172
    Are the wheel axles centred in the dropouts? Check whether the rim/sidewall is closer to one chainstay/side of the fork than the other.
    Swim. Bike. Run. Yeah. That's what I used to do.

    Bike 1
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  • Rich158
    Rich158 Posts: 2,348
    Greg T wrote:
    It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.

    I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.

    I reckon your spoke tensions off and you need to get them tightened.

    or some new mavics.


    NEW STUFF!!!!

    +1 All the best SCRer's use em...........;-)

    There's a pair sitting in my local sorting depot with my name on them :lol::lol:

    Saying that my Bontrager Racc X lites haven't missed a beat in the last year and about 8000 miles. On the other hand the set of Bonty's that came on the Mad one have lasted less than 1000 miles :evil: :evil:
    pain is temporary, the glory of beating your mates to the top of the hill lasts forever.....................

    Revised FCN - 2
  • lost_in_thought
    lost_in_thought Posts: 10,563
    Thanks all, I've got lots of checks to do this evening!

    I do have an unused (by me) pair of Rolf Primas under my bed... maybe I should just change the Khamsins for them!
  • Feltup
    Feltup Posts: 1,340
    I put some cheap slicks on my fixie CX and they are very squirmy even compared to the orignal CX tyres with nobbles. It will be interesting to see if the Rolfs cure the problem.
    Short hairy legged roadie FCN 4 or 5 in my baggies.

    Felt F55 - 2007
    Specialized Singlecross - 2008
    Marin Rift Zone - 1998
    Peugeot Tourmalet - 1983 - taken more hits than Mohammed Ali
  • gtvlusso
    gtvlusso Posts: 5,112
    Thanks all, I've got lots of checks to do this evening!

    I do have an unused (by me) pair of Rolf Primas under my bed... maybe I should just change the Khamsins for them!

    Under bed, in kitchen draw...anywhere else you keep cycle stuff?! I get a hissy fit if it comes near the house, hence, warehouse shed!
  • rolf_f
    rolf_f Posts: 16,015
    Feltup wrote:
    I put some cheap slicks on my fixie CX and they are very squirmy even compared to the orignal CX tyres with nobbles. It will be interesting to see if the Rolfs cure the problem.

    Rolfs are the best cure for everything :lol:
    Faster than a tent.......
  • Headhuunter
    Headhuunter Posts: 6,494
    JonGinge wrote:
    From the back...

    The wheel appears to be true, checked the skewer was holding it in place, will check the seat...

    No idea how to check the bearings though, and don't really know what a cone is!
    Grab the frame, grab the wheel rim and give it a bit of lateral welly. Does it move?

    Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them

    +1 on that. The bearings/rear hub is a bit loose on my Focus at the moment but the idiot at Wiggle who set the bike up has overtightened the cassette on so I need to get a chain whip to get it off to check what's going on, but sometimes it feels like there's some wobble in the rear.... If it is the hub/cones, don't overtighten them though.
    Do not write below this line. Office use only.
  • check the tyres first are they seated properly
    grab the front tyre /back tyre and shake side to side if there is play its the bearings
    or cones .
  • always_tyred
    always_tyred Posts: 4,965
    JonGinge wrote:
    From the back...

    The wheel appears to be true, checked the skewer was holding it in place, will check the seat...

    No idea how to check the bearings though, and don't really know what a cone is!
    Grab the frame, grab the wheel rim and give it a bit of lateral welly. Does it move?

    Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them

    +1 on that. The bearings/rear hub is a bit loose on my Focus at the moment but the idiot at Wiggle who set the bike up has overtightened the cassette on so I need to get a chain whip to get it off to check what's going on, but sometimes it feels like there's some wobble in the rear.... If it is the hub/cones, don't overtighten them though.
    If you don't need a chain whip to get a cassette off, either the cassette is too loose, or your freewheel is seized.