Headset loose again

elvis loved burgers
elvis loved burgers Posts: 17
edited July 2013 in Workshop
I have a Focus Variado and its constantly giving me haedset problems. Its just under a year old and within a couple of months of buying it I started to get problems. At first the headset was loose so I brought it back to the shop and they tightened it then after about 2 months it started to get really stiff while riding to the point where the bars would lock solid and I would have to get off and twist the bars quite hard to loosen it so I brought it back to the shop they stripped it down and gave it back to me telling me there was nothing wrong with it. One week later the bloody thing locked solid and wouldnt loosen at all by twisting. 10 miles from home and the same distance to the shop so I rode it back to the shop so they could see there was something wrong with it. That was an interesting cycle. Anyway the shop replaced the headset and shells with a bbb set. About 4 weeks later back to the shop when it came loose again to get it tightened. About 6 weeks ago the same shop did a bike fit and adjusted the headset. Now the bloody thing is loose again. Surely this is not normal I thought something like that should stay tight for a long time and now im starting to think the frame is knackered. Any ideas before I go back to them yet again tomorrow?

Comments

  • smoggysteve
    smoggysteve Posts: 2,909
    I don't know the Variado very well, is the fork full carbon or alu steerer?
  • elvis loved burgers
    elvis loved burgers Posts: 17
    I thought it was all carbon but after googling it I think its alloy carbon
  • smoggysteve
    smoggysteve Posts: 2,909
    In what way do you mean it is loose? Do you mean the bars move when the fork doesnt side to side or there is play in the fork vertically through the headset? If its the former, I would think maybe the bolts on the headset could do with replacing, if its the latter, it could be the join between the steerer and fork is damaged. Just a guess really without seeing it. The only thing that really holds a fork and bars straight are the two bolts on top. The star bolt, or bung on a full carbon does little to support the fork.
  • elvis loved burgers
    elvis loved burgers Posts: 17
    If I hold the front brake and rock the bike I can hear it knocking
  • estampida
    estampida Posts: 1,008
    star fangled nut is slipping

    hope head doctor to replace or similar

    service / change the bearings if they feel rough on stripdown...
  • smoggysteve
    smoggysteve Posts: 2,909
    Take the wheel off, turn the bike upside down the pull up and down on the fork, do you get any movement inside the head tube?
  • keef66
    keef66 Posts: 13,123
    Short answer to your question, no, it's not normal for a modern headset to keep loosening once it's been properly adjusted.

    The stem should be firmly clamped to the steerer tube, so even if the top cap and star-nut / expander bung went missing completely, it still shouldn't come loose. However, if the star-nut was slipping inside the steerer, it could mean the bearings were never adequately preloaded

    The only way that play can develop in a properly preloaded headset is if the bearings / cups / spacers etc start to disintegrate or if the stem is slipping up the steerer somehow.

    Stand in front of the bike and grip the front wheel between your knees. Can you turn the bars? If so it's likely the stem isn't clamping the steerer adequately.
  • neeb
    neeb Posts: 4,473
    One thing to check is that as well as the bung or star fangled nut being properly tight inside the streerer, there is enough of a gap between the top of the steerer and the top of the stem (or spacers on top of the stem) to allow the headset to be properly pre-loaded. If it's only one or two millimetres that will often be not quite enough, so the headset ends up appearing to be tightened at first but with a bit of wiggling or riding it comes loose. Often if the steerer has been cut to allow a 3mm gap, it actually ends up being 2mm or less once everything is tightened up.
  • sungod
    sungod Posts: 17,358
    1 ^^^ this

    2 find another bike shop, or, even better, learn to diy
    my bike - faster than god's and twice as shiny
  • keef66
    keef66 Posts: 13,123
    neeb wrote:
    One thing to check is that as well as the bung or star fangled nut being properly tight inside the streerer, there is enough of a gap between the top of the steerer and the top of the stem (or spacers on top of the stem) to allow the headset to be properly pre-loaded. If it's only one or two millimetres that will often be not quite enough, so the headset ends up appearing to be tightened at first but with a bit of wiggling or riding it comes loose. Often if the steerer has been cut to allow a 3mm gap, it actually ends up being 2mm or less once everything is tightened up.

    Good point. I had a 2 - 3 mm gap with when building up my new frame, but it wasn't enough to completely eliminate the play and I had to lop a bit more off the steerer to get it to fit properly.
  • elvis loved burgers
    elvis loved burgers Posts: 17
    I can only feel the play by holding the front brake and rocking the bike, I'm thinking the bearing races have been incorrectly fitted or else the frame is not right. I thought the thing should stay tight for a couple of years.
  • sungod
    sungod Posts: 17,358
    what you describe is exactly what happens if the preload is not set correctly
    my bike - faster than god's and twice as shiny
  • elvis loved burgers
    elvis loved burgers Posts: 17
    But the shop is after setting it up a good few times and even changed the whole thing yet it still comes loose after a few hundred miles. They cant be that bad in the shop so im still thinking somethings wrong with the bike
  • desweller
    desweller Posts: 5,175
    There's not much to go wrong with it. You're just locking up a bearing stack. If it's OK upon assembly and becoming loose then either the clamp screws are not being done up tight enough or there's a crack in the stem or the steerer tube that's preventing the stem from applying adequate clamping load when the pinch screws are tightened.
    - - - - - - - - - -
    On Strava.{/url}
  • neeb
    neeb Posts: 4,473
    Could you post a photo with the top cap removed? Just unscrew the bolt holding the top cap in place, lift off the top cap (leave any spacers in place) and take a photo at about 45 degrees that shows both what's underneath the top cap as well as the side of the stem and any spacers under or above it.
  • rubbernekker
    rubbernekker Posts: 112
    There area couple of things that it could be that haven't been mentioned. Occasionally when a headset has been run loose a groove is worn into the forks steerer which means that the gripper which seats into the top bearing will not seat. Only solution is a new fork- much more common on a carbon steerer though. Second- very slight bend in the steerer- this means that the gripper on the top bearing isn't in the same plane as the crown race and as you turn the stem will be forced up the steerer and cause that loose feeling. This will also cause seizing and tight spots. Hard to see how this could happen without an impact- manufacturing error? Third but least likely- the cups in the frame have been bonded in squint and and will have the same effect as the second possibility. Looseness and seizing are signs of a headset being too preloaded, then not preloaded enough, often turning the bars 90 degrees can demonstrate both in one fell swoop- and prove thatthe bearings are not parrallel. Hope you get to the bottom of it

Categories