Unstable bike

Ramekin
Ramekin Posts: 30
edited September 2010 in Workshop
My bike has recently started feeling unstable and I'm trying to isolate the problem.

The symptoms are:
1) it sometimes feels as though it's wanting to steer to one side (predominantly the right)
2) it often doesn't feel balanced when going round corners
3) and infrequently it feels like it's taking a dive to one side

As you can imagine it's a bit unsettling and I'm keen to diagnose the problem.

I don't think it's "speed wobble" as I've experienced that on a previous bike and this seems quite different.

Some points to bear in mind are:
- It's a singlespeed bike (a Condor Tempo)
- I've recently added front & rear SKS mudguards
- I've recently built a new front wheel (which as far as I can tell is true and well-tensioned)

I'd appreciate any thoughts on how best to diagnose the problem as it's frustrating to have lost confidence in the bike!

Comments

  • sungod
    sungod Posts: 17,501
    is the dishing equal both sides of the wheel?
    my bike - faster than god's and twice as shiny
  • chunkytfg
    chunkytfg Posts: 358
    is it riding straight or crabbing?
    FCN 7

    FCN 4

    if you use irrational measures to measure me, expect me to behave irrationally to measure up
  • dmch2
    dmch2 Posts: 731
    Is it the headset? Lift the front of the bike up of the ground and check that you can steer all the way from left to with with no nastiness.
    2010 Trek 1.5 Road - swissstop green, conti GP4000S
    2004 Marin Muirwoods Hybrid
  • Ramekin
    Ramekin Posts: 30
    Cheers for the quick responses.

    In answer to the questions:
    - The dishing is pretty good (at the very most about 1mm off)
    - Not sure what you mean by crabbing!
    - Headset is fine (I've checked that)
  • chunkytfg
    chunkytfg Posts: 358
    Ramekin wrote:
    Cheers for the quick responses.

    In answer to the questions:
    - The dishing is pretty good (at the very most about 1mm off)
    - Not sure what you mean by crabbing!
    - Headset is fine (I've checked that)

    When the back wheel is slightly out from true with the frame the wheels will not follow each other with the back wheel following the front one but off to the side.
    FCN 7

    FCN 4

    if you use irrational measures to measure me, expect me to behave irrationally to measure up
  • bicyclepirate
    bicyclepirate Posts: 229
    have you knocked your brake pad, sorry for the v.simple suggestion but its easy to knock one side up or down which will then catch on your wheel and feel like its dragging you in that direction.
    All hail the FSM and his noodly appendage!

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