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  1. #1
    tip
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    Another front derailleur issues thread

    I bought a late 90's Novara Randonee, it came with:

    -Shimano RSX brifters
    -Shimano RSX front derailleur
    -Shimano "Hyperdrive" front triple crankset
    -Shimano Alivio rear derailleur
    -SRAM 7 speed cassette

    [Just as a note, I am very much a novice at bike tuning/repair]

    When I picked the bike up, the rear derailleur shifted fine. The front would not shift into the largest chainring, but small and middle shifted fine. The cables and housings all looked original, so I decided to replace them. Install went smoothly, and I was able to adjust the RD properly.

    When adjusting the FD, I can't get it to shift off of the smallest chainring. I had taken the FD off and apart to clean it and see how it worked. The FD moves just fine, all the way out.

    I re-installed it, and started to adjust it. When I hit the shifter to go up one chainring, it moves over quite a ways, enough to contact and move the chain, but not enough to move the chain to the next chainring.

    I set the inside limit as close as it gets, re-adjusted the height of the FD, and
    tried rotating the clamp to move the FD closer to the chain. It still won't shift the chain over. I tried the "bow" shifting technique and the derailleur moves all the way out just fine.

    So after searching the forum, I am still looking for advice. It looks like some people have said that if your chainrings are very worn, it won't transfer the chain properly. My chainrings look worn, especially the outside 2, but the smallest chainring isn't that bad...

    So here's what I know:

    shifters work
    cables are brand new
    housings are brand new
    FD is old, original, POS?
    chainrings are pretty worn
    chain in unknown condition, but most likely very old (replace now or after I get it rideable?)

    So should I keep messing with it? Some other trick I probably don't know? Should I just buy a new FD? If so, which kind would work (RSX is obviously no longer around). Buy new chainrings? Does the old chain have anything to do with this? I am going to replace the chain at some point, I just was expecting to be able to ride it after I replaced the housings and cables.

    Thanks for any advice, I'm really trying hard to figure this out. I just want to ride it soon, then worry about upgrading components if I feel the need.

  2. #2
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    Forget the levers for the moment and shift the FD by direct pressure on the arm (where the cable attaches, or by drawing the cable away from the down tube like a bowstring.

    If that shifts the FD is fine, and use this technique to set the outer limit, so it shifts to the outer ring crisply and reliably, yet doesn't over-shift, making the chain fall off. If the cable is slack enough use a similar method to roughly set the inner limit.

    Now leave the FD, on the inner ring and shift the lever to the low gear position slackening the cable, and pull up all the slack and tighten the pinch bolt. A few pointers here, make sure the cable is on the correct side of the screw, usually the far side from the arm's pivot. if the FD cable has an adjuster someplace, (levers, frame fulcrum or in-line, bring it to the innermost position so you have the max slack take-up range. If there's no adjuster, manually bring the FD about half way between the inner and middle sprocket because you can't take up all the slack and this will allow the normal return to take up a bit more.

    Now it's a matter of fine tuning the cable for indexing fronts which is far easier with an adjuster, then fine tuning both limits.
    FB
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    An ounce of diagnosis is worth a pound of cure.

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  3. #3
    tip
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    Thanks for the tips

    Quote Originally Posted by FBinNY View Post
    If there's no adjuster, manually bring the FD about half way between the inner and middle sprocket because you can't take up all the slack and this will allow the normal return to take up a bit more.

    Now it's a matter of fine tuning the cable for indexing fronts which is far easier with an adjuster, then fine tuning both limits.
    I'm having a hard time understanding this. Regarding the adjusters that you are referring too... I think I have some on the downtube, where downtube shifters would go. I tried messing with them but they didn't seem to do much. There is no adjuster at the shift lever or anywhere else.

    When you say "manually bring the FD about halfway between the inner and middle sprocket" I'm not getting that.... Sorry, like I said, I'm new to this sorta thing.

  4. #4
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    The threaded adjuster where the housing ends on the downtube is exactly what I'm referring to. Once the cable is under tension, turning it outward will tighten it moving the FD outward (except if it's against the outer limit). When starting our it should be threaded all the way in so you can use them to tighten the cable later.

    People often have trouble pulling all the slack out of the cable, so pull the FD outward (by pulling the cage itself out) then take up the slack and tightening the pinch bolt. Now when you let go, the FD will move back in taking up the remaining slack. Be careful not to get carried away, or the you could end up with the cable too tight. But with some practice you'll dial this in and get good results.

    Also I didn't say this earlier, but often folks don't fully seat the housing in the ferrules, or into the lever, or cable stops. They pull out all the slack but once they try to shift things settle creating more slack. The key is to seat everything and get the slack out, even if it takes more than one try.

    BTW- there are a number of tutorials available on the net, free or pay to view, in both print and photos, or video format. Search "front derailleur setup" for a nice selection and review a few until you get a good sense of how it's done.
    Last edited by FBinNY; 03-09-11 at 09:26 PM.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  5. #5
    tip
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    thanks FB... I have searched all over for set up videos and I've never found that tip to take out all the slack. I tried it this morning, and now I can get it to shift to all 3 chainrings 90% of the time. I also didn't know that adjuster on the downtube did anything.

    It still needs some fine tuning, of course. But its enough for me to ride it finally. Thanks a lot for the tips. Can I fine tune the "indexes" with the adjuster on the downtube? Does "index" mean the actual position of the derailleur during a successful shift?

  6. #6
    tip
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    Well I rode it and messed with it for another hour or so.

    I'm getting frustrated... I think I'm just going to get a new FD. I tried to save it, but I just can't get it to adjust correctly and stay consistent. It seems bent and I'm done driving myself silly trying to adjust an old, crappy derailleur.

    So my next question, how hard is it going to be to find a FD? It is a 1 1/8" (28.6mm) seatpost and it is a bottom pull type. Will this work? http://www.jensonusa.com/store/produ...ra+Fd4503.aspx

  7. #7
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    If the derailleur is bent then a replacement can help.

    But if it is not bent then the issue is entirely with your setup and a new derailleur will be a waste of money and you will have the same problems if a new one is not perfectly set up. Front derailleurs are much harder to adjust than rear ones - even higher quality. FWIW, RSX is very good quality.

    If you think it is bent can you bend it back to how you think it should be?

  8. #8
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    FDs are pretty forgiving of being bent slightly. I miss the days when the cages were ductile and you could bend or tweak them to optimize shifting. If it isn't too badly bent, you might get it working by straightening it by eye. Worst possibility is the cage cracks, but you're considering buying new anyway.

    The bottom pull FD you linked is nice, and will work fine (depending on your skill of course). Just be sure to get the right clamp size.

    Lastly any the threaded adjusters on the down tube, or built on the levers, often called cable tension adjusters, might better be called trim adjusters, and that's exactly what they're for. By changing the length of the cable run they determine the precise position of the derailleur that corresponds to the clicks. After the limits are set you use a barrel adjuster to trim the derailleur for the middle position.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  9. #9
    tip
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    Quote Originally Posted by FBinNY View Post
    After the limits are set you use a barrel adjuster to trim the derailleur for the middle position.
    Okay, that makes sense. I wasn't sure what exactly to use the barrel adjuster to adjust.

    Regarding the FD being bent, it just looks tweaked. Like it has been bent many times and bent back many times. There is almost a little wave in the metal cage. I think I will try again later this afternoon before I order a new FD. Its either that, or bring it to a bike shop, which feels like I'm quitting.

  10. #10
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    When shifting from the smallest chainring to the middle chainring give the brake lever a good shove. Don't try to ease it into the index.
    Last edited by Al1943; 03-12-11 at 04:37 PM.

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