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look 986
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Discussion Starter · #1 ·
I have read many conflicting posts and reviews regarding this subject.

I am aware of the different applications for each size cage.

I ride cross country and use a long cage so i can use all gear combos. Although i don't use big-big i feel safe knowing that if i were to slip into bib-big by mistake i wont break anything.

However, if i were to opt for a medium cage i would not have this luxury but this is a sacrifice i am willing to make if it means snappier gear shifting..... but is this really true as i can't work out why a shorter cage would have this effect?

Has any one got any facts or evidence to support these claims or are they unfounded and people just saying they shift better instead of admitting they have waisted money on a new mech.
 

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Premium Member
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48,238 Posts
demc1982 said:
I have read many conflicting posts and reviews regarding this subject.

I am aware of the different applications for each size cage.

I ride cross country and use a long cage so i can use all gear combos. Although i don't use big-big i feel safe knowing that if i were to slip into bib-big by mistake i wont break anything.

However, if i were to opt for a medium cage i would not have this luxury but this is a sacrifice i am willing to make if it means snappier gear shifting..... but is this really true as i can't work out why a shorter cage would have this effect?

Has any one got any facts or evidence to support these claims or are they unfounded and people just saying they shift better instead of admitting they have waisted money on a new mech.
Basically the long and medium cage RDs use the same spring. With the shorter cage the chain has less leverage on the RD and the chain is controlled better and bounces less.
 

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Bicyclochondriac.
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demc1982 said:
I ride cross country and use a long cage so i can use all gear combos. Although i don't use big-big i feel safe knowing that if i were to slip into bib-big by mistake i wont break anything.
If you set the chain length correctly, you should have no problems going into big-big combo with a shorter cage. It is the small/small combos you may lose. The worst that will happen is that the chain goes slack and you drop it
 

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look 986
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Discussion Starter · #4 ·
ah... same spring pulling on a shorter cage increases the force that acts pulling the cage back hence increased tension.

i understand how this decreases chain bounce but does it make shifting snappier?
 

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demc1982 said:
ah... same spring pulling on a shorter cage increases the force that acts pulling the cage back hence increased tension.

i understand how this decreases chain bounce but does it make shifting snappier?
Quicker response, better control
 

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My brother uses a medium cage on his bike. And he can run 44-34, but he can't run 22-11(cage hits cog). But his bike also is a hard-tail
 

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look 986
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Discussion Starter · #8 ·
COLINx86 said:
My brother uses a medium cage on his bike. And he can run 44-34, but he can't run 22-11(cage hits cog). But his bike also is a hard-tail
thanks.... i'm using a ht too, will check my cog count tomorrow
 

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Don't recall the gearing, but I ran an XT "medium" length rear derailleur (because it was available out in the sticks of Alaska) for maybe 2 years(?) without any problems.

Never went small/small, but it always worked just fine. I do not recall snappier shifting or anything, just that it worked.

I run "long cage" now, so that might say something-
 

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I have a question. Do you guys think it would be ok to clean your chain and crank using a cotton swab? I noticed that when I cleaned my chain a few small cotton fibers would stick on the chain.
 

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How about an old toothbrush? Much better at scrubbing away grime
 

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Derailleurless
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Regarding the snappier shifting, I don't run derailleurs so much anymore, but I did run all three lengths and there was a "snappier" feel. Might have been my imagination, but...

I rationalize it using a yardstick vs. ruler analogy. Imaging holding either, hanging straight down grasped in your hand, much like an extended cage hanging off of the upper body of a rear derailleur. Move your arm side to side, simulating a shift.

There's not much weight in the yardstick, yet it is noticeably draggier than the ruler. Adding up the extra cage material, plus the extra chain links, plus the longer lever arm, it all contributes a little more resistance to the derailleur body shifting positions.

Oppositely, when the bike is jarred and the chain is deflected sideways, it has a longer lever arm with which to act on the derailleur body, possibly pulling it sideways and causing your chain to jump a cog.

six foot sloth said:
Do you guys think it would be ok to clean your chain and crank using a cotton swab?
Sure, you can come by and clean my chains any time -- just let me know when!
 

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look 986
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Discussion Starter · #13 ·
i run a sram x0 which has a strong spring, surely this spring would be man enough to provide ample tension even if it has to transmit it through a long cage.
 

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demc1982 said:
i run a sram x0 which has a strong spring, surely this spring would be man enough to provide ample tension even if it has to transmit it through a long cage.
Sure, it does have ample tension, but a shorter cage with the same spring will only be an improvement.

It's like saying I've got ample strength in my arm to flip a hamburger on the grill. But if I was comparing a 4-foot spatula to a 6-foot long spatula, and I threw in a feisty Chihuahua trying to get at my burger (to simulate the trail vibrations or whatever), I'd have an easier time beating back the rodent and flipping my patty with the shorter spatula.

It's exactly like that! :D
 

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look 986
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Discussion Starter · #15 ·
This is all good stuff!

So if the medium cage is better at everything then i can't help but think why does a long cage exist? whats the point?
 

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demc1982 said:
So if the medium cage is better at everything then i can't help but think why does a long cage exist? whats the point?
So that a rider has full use of a 3x9 drivetrain, from the useless 22x11 to the equally useless 44x34 gear combos.

...er, not that I have actual Shimano written documentation saying so, but it only makes sense. What bike dealer wants to be tasked with educating his customers in what gear combos to avoid, or deal with customers returning to the store saying "my chain fell off" or possibly "my derailleur broke" due to them shifting into a cross-chain combo.

Again, the downside of medium and short cages is they have less capacity, so not all gear combos are possible. In previous threads, a large number of riders have commented that they don't want to have to worry about cross-chaining. Long cage is for them. Others are happy to avoid the small-small combo in trade for the benefits of medium cage. The ramifications of shifting to small-small are the derailleur loses tension, and the chain drops off -- no harm other than a brief stop and an oily finger.
 

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look 986
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Discussion Starter · #17 ·
what would happen if you select big-big combo by mistake with a medium cage?
 

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meh....
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Snapier shifting with shorter cage?

I don't see how that makes a difference. The upper jockey wheel is the one doing the shifting and they're all the same afaik. The lower wheel is just for taking up the slack and keeping the chain tensioned. I'd think they'd all shift the same if they were all set up the same.
 

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Speedub.Nate said:
Sure, it does have ample tension, but a shorter cage with the same spring will only be an improvement.

It's like saying I've got ample strength in my arm to flip a hamburger on the grill. But if I was comparing a 4-foot spatula to a 6-foot long spatula, and I threw in a feisty Chihuahua trying to get at my burger (to simulate the trail vibrations or whatever), I'd have an easier time beating back the rodent and flipping my patty with the shorter spatula.

It's exactly like that! :D
Best analogy so far!
 

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look 986
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Discussion Starter · #20 ·
Monte said:
I don't see how that makes a difference. The upper jockey wheel is the one doing the shifting and they're all the same afaik. The lower wheel is just for taking up the slack and keeping the chain tensioned. I'd think they'd all shift the same if they were all set up the same.
i think it just helps with chain bounce, better tension=less bounce

maybe less bounce=better shifting over bumpy terrain?
 
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