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Shifting Problems - rear derailleur damaged?

ba68ba68 Posts: 156
edited March 2011 in Workshop
I have noticed recently that there is a definite clunk when I change up into the last couple of gears when in the largest ring on the front, everything is fine on the smaller ring. I had to change the cable a month or so ago and I thought everything was fine. As I've been wearing a skull cap under my helmet until a few weeks ago maybe I've just forgotten the noise. I did have a random clip less moment a month or so ago and scraped the RD very lightly but it's literally a light scratch so don't think any damage was suffered. Rear mech is Tiagra 9 speed with Tiagra shifters and as I mentioned shifting couldn't be smoother on the small front ring. Any advice gratefully received.

Posts

  • Buckled_RimsBuckled_Rims Posts: 1,648
    Have you checked the hanger? Even if it's very slightly bent you'll probably need a new one.
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  • John.TJohn.T Posts: 3,698
    when I change up into the last couple of gears
    Do you mean going into the small sprockets or the large ones. When going to the small ones there is often a clunk as you are usually pushing hard and it is a quick change. You want to hear the noise it makes with a disc wheel. :o
  • ba68ba68 Posts: 156
    Yes, it's when I change into the top couple (12,11 tooth) gears, all other gears are fine and all are fine when on the smallest chain ring.
  • John.TJohn.T Posts: 3,698
    Probably quite normal then. There is less chain tension on the small ring as well so the chain is not pulled in as hard.
  • itboffinitboffin Posts: 19,773
    One thing to check, are your rear derailleur jockey wheels moving freely? I thought my drive was stuffed, well the chain and cassette at least. I just couldn't get rid of the clunking in some gears and auto shifting in others.

    I removed the chain and cleaned it then whilst checking the hanger I noticed a build up of wax chain lube around the top jockey wheel, when I touched it it barely moved. Removed both cleaned and refitted re-re-indexed the gears and sweet shifting was restored.

    Good job to as the replacement parts would have been expensive.
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  • ba68ba68 Posts: 156
    @ it boffin. Will take a look at this, I'm quite meticulous about keeping my drivetrain clean particularly over the winter but it could be a build up of lube.
  • ba68ba68 Posts: 156
    @ it boffin. Will take a look at this, I'm quite meticulous about keeping my drivetrain clean particularly over the winter but it could be a build up of lube.
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