Gear hanger stripped threads

nareloc
nareloc Posts: 11
edited June 2013 in Workshop
My rear mech (Dura Ace) on my Focus IIzalco Pro came loose and when trying to tighten the two holding screws on the hanger noticed that the threads on the hanger were stripped. Not had any bangs or crashes so wonder why this has happened. Just got new hanger (£25!) and ready to fit but would appreciate any advice/tips re fitting as I don't want the same problem at this price.
Mike

Comments

  • sungod
    sungod Posts: 17,413
    could have been overtightened, or loose allowing movement and wear, or corrosion, etc.

    i always put a bit of antiseize on the screws when fitting dissimilar metals, it helps prevent galvanic corrosion
    my bike - faster than god's and twice as shiny
  • Mindermast
    Mindermast Posts: 124
    sungod wrote:
    i always put a bit of antiseize on the screws when fitting dissimilar metals, it helps prevent galvanic corrosion

    Sounds like a good idea. Do you have a less adhesive idea for seatposts? I have an alloy seatpost in a steel frame and grease is said to increase the action between both metals.
  • cycleclinic
    cycleclinic Posts: 6,865
    There is a cheaper solution. I have this tool so ask your LBS to use the tool that destroy's the old thread and cuts a large one then fit a bush/helicoil that is threaded. The hanger can screwed into that. Also grease is fine to se on seatposts. So is anti seize I suppose.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • sungod
    sungod Posts: 17,413
    Mindermast wrote:
    sungod wrote:
    i always put a bit of antiseize on the screws when fitting dissimilar metals, it helps prevent galvanic corrosion

    Sounds like a good idea. Do you have a less adhesive idea for seatposts? I have an alloy seatpost in a steel frame and grease is said to increase the action between both metals.

    antiseize isn't adhesive, it's an oily/greasy base with a metal filler as sacrificial anode, it's fine for aluminium posts in steel frames (also bb threads, pedal threads etc.)

    there are different formulations depending on the intended use, i just use the park tool one, a tube of it lasts for many years

    http://www.parktool.com/product/anti-se ... ound-asc-1
    my bike - faster than god's and twice as shiny
  • Mindermast
    Mindermast Posts: 124
    sungod wrote:
    antiseize isn't adhesive, it's an oily/greasy base with a metal filler as sacrificial anode, it's fine for aluminium posts in steel frames (also bb threads, pedal threads etc.)

    Ah, nice! I looked up antiseize on the internet and found a maker of adhesives. So I thought, it was about securing screws in the first place.

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