# Shimano Deore XT - GS or SGS derailleur



## miguelbasora (May 6, 2013)

Hi,

I'm looking for some word of wisdom here, I'm about to swap my old SLX rear derailleur, but I'm not sure which XT will fit my needs better, a GS which some sites have it as medium cage, or SGS long cage. My cassette is 11-34 9 speed, Crankset XT 42/32/24.

Thanks!


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## RTM (Sep 17, 2005)

miguelbasora said:


> Hi,
> 
> I'm looking for some word of wisdom here, I'm about to swap my old SLX rear derailleur, but I'm not sure which XT will fit my needs better, a GS which some sites have it as medium cage, or SGS long cage. My cassette is 11-34 9 speed, Crankset XT 42/32/24.
> 
> Thanks!


Medium cage is a better choice.


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## miguelbasora (May 6, 2013)

RTM said:


> Medium cage is a better choice.


Is there any specific advantage versus the long cage?


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## RTM (Sep 17, 2005)

miguelbasora said:


> Is there any specific advantage versus the long cage?


The long cage is more prone to catching sticks and rocks and in my experience the long is not as consistently crisp. Generally speaking the shortest cage possible is desirable. 3x9, medium is good, and it's as short as you want to go.

- Rob


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## Aresab (Mar 27, 2007)

If you are staying with a triple ring up front, the SGS long cage would be a better fit as it will be able to take of the slack in the chain better. See the sticky at the top of the drivetrain forum. The GS would be good if you but a bash on instead of the 42T. Also, is your SLX worn out? There is not a huge difference between SLX and XT (weight/sealed bearing jockey wheels) and shifting should be very much identical. Shifters on the other hand may be more noticeable. Just a some thoughts for you!


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## jeffj (Jan 13, 2004)

RSabarese said:


> If you are staying with a triple ring up front, the SGS long cage would be a better fit as it will be able to take of the slack in the chain better. See the sticky at the top of the drivetrain forum. The GS would be good if you but a bash on instead of the 42T. Also, is your SLX worn out? There is not a huge difference between SLX and XT (weight/sealed bearing jockey wheels) and shifting should be very much identical. Shifters on the other hand may be more noticeable. Just a some thoughts for you!


+1

For that gearing combo F&R, stick with the long cage. And, I don't know that I would look for any improvement in shifting if your SLX RD is not damaged. If you want a noticeable difference from a standard rear derailleur, get a Shadow Plus. The elimination of chain slap with the Shadow Plus (or SRAM Type 2, which will not fit your shifters), is the biggest improvement in the rear derailleur in many, many years.

I'd take a lower level Shadow Plus rear derailleur over a higher level non-Shadow Plus rear derailleur any day of the week.


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## eb1888 (Jan 27, 2012)

To go Plus you need to also change to 10 speed rear with a new rear shifter and cassette and chain. Your 9 speed front will continue to work because the ring tooth width doesn't change. The side plates on the chain are thinner.
Going GS can be a good idea in 9 or 10 speed. But it will not have enough scope to allow a small front ring to small rear cog choice. Realistically this is something no one would use so you don't need to provide for it. No chain breakage just too much slack. This is considered an advanced rider choice for riders with good mech skills.


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## jeffj (Jan 13, 2004)

eb1888 said:


> To go Plus you need to also change to 10 speed rear with a new rear shifter and cassette and chain. Your 9 speed front will continue to work because the ring tooth width doesn't change. The side plates on the chain are thinner.
> Going GS can be a good idea in 9 or 10 speed. But it will not have enough scope to allow a small front ring to small rear cog choice. Realistically this is something no one would use so you don't need to provide for it. No chain breakage just too much slack. This is considered an advanced rider choice for riders with good mech skills.


Good catch on needing to be 10 speed. Doh!

You can get the medium cage to work with a triple, but unless one understands the nuances of shifting and the limitations the medium cage will bring, I would still recommend the long cage to newer riders or they will have issues at best, or start breaking s**t at worst. And unless you're prone to breaking off derailleur by snagging them, it may not be worth the tradeoff anyway. JMHO.


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## Slash5 (Nov 27, 2011)

You need a long cage. Your tooth difference is 41, much more than the medium cage capacity.


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## RTM (Sep 17, 2005)

Yeah, I guess I stand corrected. Long cage is good advice. I was thinking, as is generally the case, that you probably won't use the big ring a lot, if ever. But these guys are technically right. If you plan to use the big ring consistently you will get best overall performance out of the long cage.


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## GTscoob (Apr 27, 2009)

jeffj said:


> You can get the medium cage to work with a triple, but unless one understands the nuances of shifting and the limitations the medium cage will bring, I would still recommend the long cage to newer riders or they will have issues at best, or start breaking s**t at worst. And unless you're prone to breaking off derailleur by snagging them, it may not be worth the tradeoff anyway. JMHO.


This. If you're careful about knowing which chainring you're in and want a lighter, stiffer rear derailleur with more ground clearance, get a mid cage. If you tend to just ride get the long cage.


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## eb1888 (Jan 27, 2012)

It's not the big ring that you should consider. You will leave the chain long enough to handle the length needed to go big to big and avoid snapping the chain.. A this point the derailleur doesn't matter because there is no slack to take up.
Because you need that length the chain is too long for small front to small back without a long cage to take up the extra length.
So consider how much you will ride in the smallest front ring-- probably rarely once you have some endurance capability. And second, consider how often you use the smallest front ring with say the smallest three cogs on the rear-- most likely never. If you mistakenly try the chain will hang a little, not do an immediate snap.
You could cut the length to work with a mid cage and the two mid and small rings on the front and the small cog on the rear. Then you could snap a chain using the large ring and a large rear cog.


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## Harold (Dec 23, 2003)

If you are careful about your shifting and can avoid getting yourself into a situation that the shorter cage derailleur can't handle, you could do it. If you are very much a beginner and don't pay as much attention to your shifting, like my wife, then don't put a medium cage derailleur on a triple.

This old thread does a good job of covering cage length for a given drivetrain.

http://forums.mtbr.com/drivetrain-s...ong-cage-vs-short-cage-derailleur-205890.html


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