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  1. #1
    Senior Member
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    Shimano 105 STI Rear Shifter in "Failure" Mode

    I have a road bike with a Shimano 105 STI rear shifter in what I've seen called "failure" mode. I can shift into lower gears with no problem, but I cannot shift into a higher gear without holding the brake lever in place as the shifter lever sticks to the brake lever when trying to shift into higher gears.

    I've done some google searches and determined that this is a somewhat common problem with Shimano STI shifters. However, the only fix I've read about is to replace the shifters - possibly through a warranty. But, I bought this bike used a few months ago and don't have a clue as to the availablility of the warranty as I don't know the history of when the shifters were placed on the bike.

    I've tried to flush the shifter with WD-40 to no avail. Any other ideas?

    I've thought about replacing the shifters, but I don't want to drop a lot of $$$ into the bike as I may get a new bike in the next six months or so. I've thought about going a cheaper route and placing bar-end or down-tube shifters on the bike until I replace it with a new bike.

    My only concern about buying a used replacement STI shifter on eBay or the like is that a used replacement may be on the verge of having the same problem.

    I'm wondering if this problem occurred on only a certain timeframe of manufacture of STI shifters. Maybe this problem has been cured in a newer set of shifters. Anyone know?

    The shifters are 9-speed version - I don't have the model number with me here at work.

    Thanks in advance,

    Cain

  2. #2
    Senior Member kbabin's Avatar
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    Hey Cain,

    Did you get this fixed?

    Kev

  3. #3
    I am not a car Map tester's Avatar
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    May 2004
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    Passing on this advice:
    if the problem is the "pawls" in the shifter ratchet not engaging (characterized by no resistance/noise/tactile sensation when the lever runs through its range of motion) then a simple solution may be to spray some form of degreaser (tri-flow also works very well) into the shifter. repeatedly work the lever putting a slight force in an orthogonal (perpendicular to the plane that the swept motion of the lever is in) direction, this may result in the eventual breakdown of the coagulated grease that is hindering the free-ratcheting motion of the pawls. this is the ONLY "service technique" that Shimano ever discusses for any of their shifters. if this does not work step two is to replace the defective unit.
    dura-ace has a three year warranty from date of purchase.
    "Bad facts make bad laws." FZ

  4. #4
    Senior Member
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    Thanks for the info.

    Kev, no I didn't get it fixed. I tried spraying out all the crud in it before lubing it. I used someone's suggestion of spraying carborator cleaner to get out the oily grime. Well it cleaned it out alright, along with the paint and coatings on the plastic and metal, respectively. Oh well, it was already trashed.

    I've already ordered a replacement.

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