Chain running straight?

timbo_tim
timbo_tim Posts: 199
edited September 2016 in Workshop
Not sure how best to explain this, but when I look down at my front derailleur and spin the pedals, the chain doesn't seem to go through straight, as such at some point during a complete revolution of the chain it might rub the derailleur. It would imply to me something isn't straight in the system but I am not sure what! The BB is a square taper cartridge so presumably as its screwed in all the way it can't be screwed in "off centre", or can it?

Any ideas what it might be?

Comments

  • dowtcha
    dowtcha Posts: 442
    Bent or stiff link? Put a mark on the chain and see if it happens at the same point each revolution.
  • balthazar
    balthazar Posts: 1,565
    Crank/chainrings are not always perfectly in plane. Perceptible error is normal, it doesn't trouble front shifting but does remind you to trim the front mech position occasionally.
  • timbo_tim
    timbo_tim Posts: 199
    Thanks, had the bike a while so surprised I've not noticed it before, though I confess I did change the chain recently and may have messed up the pin on the joining link. On hindsight the misalignment happens less than one revolution of the chainring. Will check the links tomorrow...

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