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  1. #1
    cbx
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    Front Der Cable Stretch

    Hey All,
    I recently swapped my shifter cables and installed some braided Jagwire housings and cables. I prestretched everything, but I seem to be getting some additional stretching after a few rides on the front der. (ie, the der. cage seems to be further from the chain than it was when I installed and stretched the cables) This sound normal? I'm curious on older XTR front derailleurs have a spring tension adjustment? Is it perhaps the spring tension is too tight and its causing premature stretching?

  2. #2
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    Good cables don't really stretch...most cables anymore don't except the ultra cheap twisted galvanized ones. Usually it's just the housing and end caps seating in. As long as your limit screws are where they should be and the derailleur is clamped in place, the stretch should go away on the first ride or two. On a new install I hook up the cable, pull hard on an exposed section while holding the cage in place, loosen and pull out any slack from the cable before retightening, and it's usually good to go. Barrel adjustments are almost always enough to take care of any slack that appears later. Is there any chance you maybe had the shifter bumped one gear while you were installing the cable?

    As for spring tension, I'm not aware of any front derailleurs that were ever offered with adjustable tension.

    Side note, I've had and seen front shifting weirdness from full suspension frames that had cracked seat tubes. I had a creak in one of mine that I couldn't figure out...turned out to be the frame. When it blew up on a ride the seat tube down near the derailleur completely sheared, which allowed the shock to expand....that pulled the shift cable and very suddenly I was pedaling in the big ring.

  3. #3
    cbx
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    Thank you for the input!

    I'm on an xc hardtail so that rules out the FS concern. I think since I shift so much between the middle and big rings, my housing is compressing. I'm considering buying a new front derailleur that might have stiffer pivots and lighter action which might help. Thank you for the setup tips! I will keep a further eye on it and update after another ride or two.

  4. #4
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    While there's a tiny bit of stretch in cables and a comparably tiny bit of compression in housings, we're talking about very tiny changes, and I'd be surprised that you'd notice any true stretch or compression in the amount of time involved.

    Odds are what you're seeing is seating of the head in the lever, settling of the housing in the ferrules, or slippage at the anchor bolt. These are the common causes of "cable stretch" after new installations. Near the end of your cable's life it'll begin to stretch anew, this time for real, as it begins to fatigue and fray prior to breaking.

    Re-adjust based on the cables current length and make sure to properly tighten the anchor bolt, and you should then get months of adjustment free riding.
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