Derailleur Size

If you're in a shop, ask the salesman.

- -

"May you have the wind at your back.
And a really low gear for the hills!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner
http://www.geocities.com/czcorner

On Tue, 27 Jul 2004 19:08:37 -0400, "pjx" <[email hidden]>

Quoted message said:

How does one tell which one of the different types is on a particular bike?

PJ

I'm relativly new, so take this with a grain of salt. 🙂

Ass-uming you are talkign 'modern' derailers, the two most important
things are the number of speeds and the 'cage' length. Naturally, you
want a derailur that will shift the # of speeds you have on your
cassete. Note that the actual indexing (if your using it) is
controlled by the shifter, not the derailer.

Cage length determains the maximum difference in teeth you can shift.
I know that for Shimano you can go to there web site and look up the
data sheets and find this out. For instance, I've been looking at
mountain bike derailers. The Deore LX M570 will shift a total of 43T.
This is front & rear. I have a tripple on this bike, which is a
52-42-30, so my front difference is 22t, leaving me 21t difference for
the cassette, like a 11-32.

If your taking front derailer, there is clamp size (based on your
frames seat tube diameter) and probably something else I don't know.
🙂

Ken

Ken,

I am looking to replace a Suntour Derailleur with a older Shimano.
The Suntour is on a six gear cassete. I think that I have a Long Cage
because I measured from the outside of both pullies and got 5". Which one
can shift more gears, long or short cage?

Paul

Paul
"KD" <kmorton.at.dsl-only.net> wrote in message
news:[email hidden]...

Quoted message said:

On Tue, 27 Jul 2004 19:08:37 -0400, "pjx" <[email hidden]>

Quoted message said:

How does one tell which one of the different types is on a particular

bike?

Quoted message said:

Quoted message said:

PJ

I'm relativly new, so take this with a grain of salt. 🙂

Ass-uming you are talkign 'modern' derailers, the two most important
things are the number of speeds and the 'cage' length. Naturally, you
want a derailur that will shift the # of speeds you have on your
cassete. Note that the actual indexing (if your using it) is
controlled by the shifter, not the derailer.

Cage length determains the maximum difference in teeth you can shift.
I know that for Shimano you can go to there web site and look up the
data sheets and find this out. For instance, I've been looking at
mountain bike derailers. The Deore LX M570 will shift a total of 43T.
This is front & rear. I have a tripple on this bike, which is a
52-42-30, so my front difference is 22t, leaving me 21t difference for
the cassette, like a 11-32.

If your taking front derailer, there is clamp size (based on your
frames seat tube diameter) and probably something else I don't know.
🙂

Ken

pjx said:

Quoted message said:

How does one tell which one of the different types is on a particular bike?

A well meaning poster replied:

Quoted message said:

I'm relativly new, so take this with a grain of salt. 🙂

Ass-uming you are talkign 'modern' derailers, the two most important
things are the number of speeds and the 'cage' length. Naturally, you
want a derailur that will shift the # of speeds you have on your
cassete. Note that the actual indexing (if your using it) is
controlled by the shifter, not the derailer.

Actually, the number of speeds is generally not an issue in practice,
that's more of a marketing device than a functional difference, unless
you're talking about seriously ancient stuff.

Quoted message said:

Cage length determains the maximum difference in teeth you can shift.
I know that for Shimano you can go to there web site and look up the
data sheets and find this out. For instance, I've been looking at
mountain bike derailers. The Deore LX M570 will shift a total of 43T.
This is front & rear. I have a tripple on this bike, which is a
52-42-30, so my front difference is 22t, leaving me 21t difference for
the cassette, like a 11-32.

See also: http://sheldonbrown.com/capacity

Quoted message said:

If your taking front derailer, there is clamp size (based on your
frames seat tube diameter) and probably something else I don't know.
🙂

Yep, fronts get complicated! There are doubles and triples, top pull
and bottom pull (cable routing), "road" vs "mountain" indexing, and the
issue of matching the curvature of the cage to the size of the largest
chainring.

See: http://sheldonbrown.com/harris/derailers

Sheldon "It Gets Complicated" Brown
+-----------------------------------------+
| When I cannot sing my heart, |
| I can only speak my mind... |
| --John Lennon |
+-----------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

pjx said:

I am looking to replace a Suntour Derailleur with a older Shimano.
The Suntour is on a six gear cassete.

Nope, that would be a freewheel. Sun Tour never made 6-speed cassette
hubs, fortunately.

Quoted message said:

I think that I have a Long Cage
because I measured from the outside of both pullies and got 5". Which one
can shift more gears, long or short cage?

The length of the cage doesn't have anything to do with the number of
gears, it relates to the difference in size between the biggest and
smallest. Long cages can take up more slack in the chain, so they'll
generally handle a wider gear range than short cage units.

Sheldon "http://sheldonbrown.com/derailer-adjustment" Brown
+--------------------------------------------+
| Life is what happens to you, |
| while you're busy making other plans. |
| --John Lennon |
+--------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Paul,

A long cage will shift more teeth than a short cage. I don't know
nothing about 6-speed stuff. :P

Ken

On Wed, 28 Jul 2004 19:32:48 -0400, "pjx" <[email hidden]>

Quoted message said:

Ken,

I am looking to replace a Suntour Derailleur with a older Shimano.
The Suntour is on a six gear cassete. I think that I have a Long Cage
because I measured from the outside of both pullies and got 5". Which one
can shift more gears, long or short cage?

Paul

Paul
"KD" <kmorton.at.dsl-only.net> wrote in message
news:[email hidden]...

Quoted message said:

On Tue, 27 Jul 2004 19:08:37 -0400, "pjx" <[email hidden]>

Quoted message said:

How does one tell which one of the different types is on a particular

bike?

Quoted message said:

Quoted message said:

PJ

I'm relativly new, so take this with a grain of salt. 🙂

Ass-uming you are talkign 'modern' derailers, the two most important
things are the number of speeds and the 'cage' length. Naturally, you
want a derailur that will shift the # of speeds you have on your
cassete. Note that the actual indexing (if your using it) is
controlled by the shifter, not the derailer.

Cage length determains the maximum difference in teeth you can shift.
I know that for Shimano you can go to there web site and look up the
data sheets and find this out. For instance, I've been looking at
mountain bike derailers. The Deore LX M570 will shift a total of 43T.
This is front & rear. I have a tripple on this bike, which is a
52-42-30, so my front difference is 22t, leaving me 21t difference for
the cassette, like a 11-32.

If your taking front derailer, there is clamp size (based on your
frames seat tube diameter) and probably something else I don't know.
🙂

Ken