How can I tell what type of front derailluer I have?

Discussion in 'Mountain Bikes' started by Tacomaboy, Jun 2, 2003.

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  1. Tacomaboy

    Tacomaboy Guest

    How can I tell if mine is top swing, etc etc. I know it isnt post moung, it mounts to the BB. Does
    this limit the type of derailluers I can buy? I am looking into getting a new XT soon...
     
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  2. Nelson Binch

    Nelson Binch Guest

    "TacomaBoy" <[email protected]> wrote in message
    news:[email protected]...
    | How can I tell if mine is top swing, etc etc. I know it isnt post moung,
    it
    | mounts to the BB. Does this limit the type of derailluers I can buy? I
    am
    | looking into getting a new XT soon...

    Bottom bracket mounted derailleurs are referred to as "E" type derailleurs and IIRC all of them are
    considered top swing. Unless you have a frame that requires this type of mount, they are not
    necessary. Generally, the most important issues in choosing a replacement are pull direction and
    clamp diameter. Measure (or have somebody with calipers) measure the seat tube where the derailleur
    would clamp on. It should be close to 1 1/8 inch, 1
    1/4 inch or 1 3/8 inch.

    If you plan on using small rings (up to 44 tooth) a top swing model will work okay. Larger rings,
    you need (but not necessarily require) a bottom swing (high clamp - I've gotten low clamped Top
    Swing models to shift 48 teeth dependably)

    You may need a washer to take up the space created by taking off the BB mounted model.

    All of this goes out the window if the frame won't allow a clamp type der.

    ---
    __o _`\(,_ Cycling is life, (_)/ (_) all the rest, just details. Nelson Binch =^o.o^=
    http://intergalax.com

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  3. Tacomaboy

    Tacomaboy Guest

    "Nelson Binch" <[email protected]> wrote in message
    news:[email protected]...
    > "TacomaBoy" <[email protected]> wrote in message
    > news:[email protected]...
    > | How can I tell if mine is top swing, etc etc. I know it isnt post
    moung,
    > it
    > | mounts to the BB. Does this limit the type of derailluers I can buy? I
    > am
    > | looking into getting a new XT soon...
    >
    > Bottom bracket mounted derailleurs are referred to as "E" type derailleurs and IIRC all of them
    > are considered top swing. Unless you have a frame
    that
    > requires this type of mount, they are not necessary. Generally, the most important issues in
    > choosing a replacement are pull direction and clamp diameter. Measure (or have somebody with
    > calipers) measure the seat tube where the derailleur would clamp on. It should be close to 1
    > 1/8 inch, 1
    > 1/4 inch or 1 3/8 inch.
    >
    > If you plan on using small rings (up to 44 tooth) a top swing model will work okay. Larger rings,
    > you need (but not necessarily require) a bottom swing (high clamp - I've gotten low clamped Top
    > Swing models to shift 48 teeth dependably)
    >
    > You may need a washer to take up the space created by taking off the BB mounted model.
    >
    > All of this goes out the window if the frame won't allow a clamp type der.
    >

    Thanks for that, very helpful. I believe my bike NEEDS a BB mount, since it has an odd shaped, frame
    (2000 Rockhopper FSR). Top swing means the hinge is on top, correct? If I bought a topswing with,
    say, a 1 1/8" mount, could I take the mount off and attach the derailleur to the BB mount?
     
  4. Nelson Binch

    Nelson Binch Guest

    "TacomaBoy" <[email protected]> wrote in message
    news:[email protected]...
    | "Nelson Binch" <[email protected]> wrote in message
    | news:[email protected]...
    | > "TacomaBoy" <[email protected]> wrote in message
    | > news:[email protected]...
    | > | How can I tell if mine is top swing, etc etc. I know it isnt post
    | moung,
    | > it
    | > | mounts to the BB. Does this limit the type of derailluers I can buy?
    I
    | > am
    | > | looking into getting a new XT soon...
    | >
    | > Bottom bracket mounted derailleurs are referred to as "E" type
    derailleurs
    | > and IIRC all of them are considered top swing. Unless you have a frame
    | that
    | > requires this type of mount, they are not necessary. Generally, the
    most
    | > important issues in choosing a replacement are pull direction and clamp diameter. Measure (or
    | > have somebody with calipers) measure the seat
    tube
    | > where the derailleur would clamp on. It should be close to 1 1/8 inch,
    1
    | > 1/4 inch or 1 3/8 inch.
    | >
    | > If you plan on using small rings (up to 44 tooth) a top swing model will work okay. Larger
    | > rings, you need (but not necessarily require) a
    bottom
    | > swing (high clamp - I've gotten low clamped Top Swing models to shift 48 teeth dependably)
    | >
    | > You may need a washer to take up the space created by taking off the BB mounted model.
    | >
    | > All of this goes out the window if the frame won't allow a clamp type
    der.
    | >
    |
    | Thanks for that, very helpful. I believe my bike NEEDS a BB mount, since
    it
    | has an odd shaped, frame (2000 Rockhopper FSR). Top swing means the hinge is on top, correct? If I
    | bought a topswing with, say, a 1 1/8" mount,
    could
    | I take the mount off and attach the derailleur to the BB mount?
    |
    |

    Top swing actually means the pivots are BELOW the cage. I think the FSR would allow some clamped
    models, but stitching the mechanisms isn't as easy as it sounds. Some of the pivots are riveted
    instead of e-clipped. If you stay with the E type, then use the XT for up to 44 tooth big rings and
    the XTR for anything larger.

    ---
    __o _`\(,_ Cycling is life, (_)/ (_) all the rest, just details. Nelson Binch =^o.o^=
    http://intergalax.com

    Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.486 / Virus Database: 284 -
    Release Date: 5/29/2003
     
  5. Bill Wheeler

    Bill Wheeler Guest

    On Mon, 2 Jun 2003 15:51:57 -0500, "TacomaBoy" <[email protected]> wrote:

    >How can I tell if mine is top swing, etc etc. I know it isnt post moung, it mounts to the BB. Does
    >this limit the type of derailluers I can buy? I am looking into getting a new XT soon...
    >

    Why the hell do you need a front derailleur?

    Things that make you go hmmmm, Bill The mind serves properly as a window glass rather than as
    a reflector, that is, the mind should give an immediate view instead of an interpretation of
    the world.
    :-]
     
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