Rear mech sorted play in fork/headset help

squibnocket
squibnocket Posts: 207
edited July 2011 in Workshop
Hi again,

Sorted the rear mech fundamental error, the cable had not seated and had pulled past the part where it seats. The next problem I have is i have tightened the headset at the top I then applied the front brake and I noticed play when the brake was fully applied, I hope I have explained the problem, any help as before much appreciated.

Cheers

Comments

  • balthazar
    balthazar Posts: 1,565
    You need to loosen the stem bolts before you adjust the bearings, and tighten them afterwards. With the stem bolts loosened so the stem slides freely on the steerer, tighten the top cap bolt gently, a quarter-turn at a time, until the head bearing is just preloaded enough to prevent play, but not so much that it binds. It is a delicate adjustment that may take a few tries.

    When you're satisfied, tighten up the stem bolts to fix everything. Bouncing the front of the bike on the ground is one way to reveal a slightly loose headset: you'll hear it, as an ugly shimmy.

    This all assumes that your fork steerer and stem stack are cut and specified to the appropriate dimensions.
  • squibnocket
    squibnocket Posts: 207
    I'm a complete novice at this so forgive me if the next question sounds ridiculous, so do i need to put a slightly larger spacer on the top of the fork under the handlebar stem? :?
  • balthazar
    balthazar Posts: 1,565
    edited July 2011
    You should make sure that the stack of stem+spacers is a little higher (2mm or so) than the steerer (the internal tube that is part of the forks). The function of the top cap bolt is to push against this "stack", applying pressure (preload) against the headset bearings, allowing careful control. It doesn't matter which order all the parts are in: the spacers could be above or below the stem, depending only on your preference for fit.

    No apologies necessary. But, if you're unclear about this, research it either in videos online, or – ideally – by having somebody in a shop (or otherwise knowledgable) show you. It is a simple interface to understand, but complicated to describe; my experience from queries here, is that many misunderstand it.
  • squibnocket
    squibnocket Posts: 207
    Thanks for that I've got some more spacers and I had just put enough spacers on to come level but now you mention it, it does make sense to have the spacers come over the top so to speak. I want to get back in the shed now :lol:

    Thanks for your help.

    Pics will follow soon.

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