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friction front derailleur vs indexed?

chrissiebchrissieb Posts: 8
edited April 2008 in MTB workshop & tech
Hello, sorry if I'm being a dumb noob, but I need some help with my front derailleur...

I just replaced an old shimano SIS friction shifter with a shimano stx 3 speed indexed trigger shifter. I'm trying to set the gears up, but having no joy- if I put a lot of tension on the cable, I can't physically shift the gears. If I slacken it off, I can select all 3 settings, but the derailleur hardly moves at all between two of the settings, so it's useless.

I suspect that maybe friction and index derailleures need a different amount of force and aren't interchangeable and I'm wasting my time, is this so?

If I junk the derailleur and get a shimano stx one, are there any chain ring compatability issues I need to be aware of? I'm using a truvative isoflow trushift 3 ring chainset.

Sorry, I'm new to this..!

advise welcome, x

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    it should work fine. it sounds like you have some thing not set up correctly.

    what is the front mech? also what is the bike.

    have a good look at Parktools as well.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • nicklouse wrote:
    it should work fine. it sounds like you have some thing not set up correctly.

    what is the front mech? also what is the bike.

    have a good look at Parktools as well.

    hmm... not sure what I'm doing wrong then! I managed to set it up when I was using a friction shifter, but I'm not getting anywhere with the indexed one.

    The front mech is a shimano one, but there is no model name on there. I was given the bike to learn on, it's an old cheapo mountain bike, A Universal Rampage I think! I've been gradually doing it up as a project.

    I've been using the haynes bike book and had a quick look at park, but I'll try again.... maybe I won't need to spend money after all!

    cheers, x
  • supersonicsupersonic Posts: 82,708 Lives Here
    Is the cage moving freely ie not siezed? Cable running free too? Clamped in the right place? They can be very fiddly, but keep going!
  • y'know, this is going to make me sound like a time waster, but I think I'm getting somewhere now! After Nicklouse's email, I had another go at re-tensioning the cable, and I can now move the cage to all three positions without breaking my thumb off... I've been trying for2 days but I think I finally got somewhere!

    I think NL's advice to check park tools was good- I didn't have the chain running over the smallest sprocket, so I guess it's really important to have a straight chain line when trying to do this.

    I'm a long way to having a working front derailleur, but I'll perserver... back to it, must stop putting grease on my laptop.

    x
  • oh spoke to soon... it's still just as bad :(.

    I'll keep trying!
  • nicklousenicklouse Posts: 81,520 Lives Here
    your welcome.

    latex gloves are useful :wink:
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • supersonicsupersonic Posts: 82,708 Lives Here
    If having to push that hard to get it to move, something is not right - either the pivots are siezing, or the cable is shagged.
  • the cable is new, what do you mean by pivots? Pivots inside the derailleur?

    It actually feels quite floppy, and it doesn't look ruste or anything.... plus it was working previously... I'll go through the set up step by step again and see if I can get any where.

    I'm really confused by it, I honestly thought maybe the derailleur wasn't compatible with the shifter.
  • supersonicsupersonic Posts: 82,708 Lives Here
    Yeah, the derailer pivots. Try and move it by hand - does it spring back easy?
  • yeah, it's hard to move but it does spring back.
  • *sigh*, no joy.... don't want to admit defeat yet, but it might be a job for someone who knows what they are doing!

    thanks to both of you for your help x
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