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



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Tacomaboy

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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...
 
"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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"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?
 
"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

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Release Date: 5/29/2003
 
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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