Medium or Large Cage Rear Derailleur?

[Honestcox]

I just trashed my rear derailleur and need to get a new one. Upon looking for a new one, I realized my original was a medium cage. (SRAM X-7). All I could find locally were large cage derailleurs (X-7 or X-9). I understand that large cage derailleurs offer capacity for all the cog/chain ring combinations. I have always avoided going to the extreme combinations of small cog/small chain ring etc. and never had any issues with my medium cage derailleur i.e. I don't need the benefit a large cage would provide.

There are pros and cons to both the large and medium cage sizes, but what should I do - replace with a large cage or stick with a medium cage? What do most mountain bikes have? I am assuming long cage . . .

Any thoughts will be appreciated!

[Rage]

Depends on your front setup. If you're running a 1x9 or 2x9, then a medium cage is fine. I'd stay with a long cage for a 3x9. Long cage are much more available and will cover all bases. I like a medium cage for urban stuff, but that's because the derailleur is pretty exposed to grinds. Most bikes have long cage, by far. Of course, if you chg to a long cage you'll likely need a new chain.

Rg.

[Honestcox]

Thanks for the reply - interesting thing is this bike came stock with the medium cage X-7. (Specialized Rockhopper Pro)

[Rage]

Huh, that's odd. The Specialized specs show a 3x9 setup with a long cage. Again, not sure what your gearing is so if you're not a 3x9 you're prolly ok.

A medium cage has a 37T capacity whereas a long cage can handle 45T. Let's say you're a 2x9 with 11-34 rear and 22-32 front. You got 23T spread on the rear and 10T spread on the front for 33T total spread, so a medium will work. A typical 3x9 with 22-32-44 front will have 22T front (added to the 23T rear) for 45T total, so you need a long cage. A 3x9 could only shift up to the 15 tooth cog with a medium cage derailluer which would make the big ring pretty much unusable IMHO.

Rg.

[jimithng23]

Huh, that's odd. The Specialized specs show a 3x9 setup with a long cage. Again, not sure what your gearing is so if you're not a 3x9 you're prolly ok.

A medium cage has a 37T capacity whereas a long cage can handle 45T. Let's say you're a 2x9 with 11-34 rear and 22-32 front. You got 23T spread on the rear and 10T spread on the front for 33T total spread, so a medium will work. A typical 3x9 with 22-32-44 front will have 22T front (added to the 23T rear) for 45T total, so you need a long cage. A 3x9 could only shift up to the 15 tooth cog with a medium cage derailluer which would make the big ring pretty much unusable IMHO.

Rg.

that's an awful lot of math on a Sunday morning...sheesh

[Honestcox]

Huh, that's odd. The Specialized specs show a 3x9 setup with a long cage. Again, not sure what your gearing is so if you're not a 3x9 you're prolly ok.

A medium cage has a 37T capacity whereas a long cage can handle 45T. Let's say you're a 2x9 with 11-34 rear and 22-32 front. You got 23T spread on the rear and 10T spread on the front for 33T total spread, so a medium will work. A typical 3x9 with 22-32-44 front will have 22T front (added to the 23T rear) for 45T total, so you need a long cage. A 3x9 could only shift up to the 15 tooth cog with a medium cage derailluer which would make the big ring pretty much unusable IMHO.

Rg.

I agree with your math - my setup is the standard 3x9 with the standard number of teeth you quote, and technically the medium cage should not work, but it actually worked and I never had any issues. I always avoided going from the big ring to the biggest cog, so never ran into trouble. I have the 2009 model and they do show the med cage was standard with that model:

http://www.specialized.com/zz/en/bc/...3&menuItemId=0

But I am going with the long cage! Going to put it on right now . . . Thanks for the input!

[Rage]

I have the 2009 model and they do show the med cage was standard with that model...

Well, I'll be duped.

Rg.

[Honestcox]

Just to close the loop - to satisfy my curiosity I contacted Specialized. The story they gave is that if their bike designers can get away with a medium cage, sometimes they'll do it. No problem either way with large or medium cage.

Now that I put the large cage derailleur on along with a new chain, I am finding the rest of my drivetrain is worn - may need new chainrings too, which is par for the course I guess . . . $$$

[Gunchie]

Just to close the loop - to satisfy my curiosity I contacted Specialized. The story they gave is that if their bike designers can get away with a medium cage, sometimes they'll do it. No problem either way with large or medium cage.

Now that I put the large cage derailleur on along with a new chain, I am finding the rest of my drivetrain is worn - may need new chainrings too, which is par for the course I guess . . . $$$

It's a good idea to change out the cassette when you get a new chain (if it has a lot of wear that is) as well. Like most Midwest riders I'm guessing you spend the majority of your time in the middle chainring. I'd just change that one out if it's that worn. Do the cassette first and see how it feels then. Changing out the cassette is a good way to loss weight on your bike anyway. Here's a XT on sell: http://www.jensonusa.com/store/produ...+Sprocket.aspx

[bleedfororbea]

wow look at that capitan colorado

like most midwest riders i'm quessing you spend the majority of your time in the middle chainring

maybe he spends it in the big ring ;) or has a double and spends it in the high or low

[Gunchie]

wow look at that capitan colorado maybe he spends it in the big ring ;) or has a double and spends it in the high or low

My goal is to stay in the middle chainring even though the pain tells me to go to granny :)

[bleedfororbea]

you running old 3by 22,32,44? if so you should get what russ has. What is it 34,40 or like 26, 40 somthin like that.

[Gunchie]

you running old 3by 22,32,44? if so you should get what russ has. What is it 34,40 or like 26, 40 somthin like that.

Nah. If I'm going to change my gear ratios I'm going 2x10.

[Russhole]

I boutght a 2 ring crank 42/27, then JB gave me a 9 spd shifter. With the 9 spd cassette I don't need my small ring in the front. I wish I had a 1 by 9 now. I think I'm going to change out to a 42/ 30 something (see what's available) when it's worn so I can keep the chain straighter and not have such a big jump from big to small ring.

[Vibrato]

THREAD HIJACK!!

Hey Russ- You ride strong so don't get me wrong, but you might want to consider a granny for the moab trip. It's not that you couldn't do it without one, but you might be more comfortable and have more energy throughout the week if you did.

Keep in mind that even on the day we do the shuttle and 7,000 ft of decent, that 26 miles of trail also has 2000 ft of climbing. 2000 ft of climbing is like doing LT 15 or 20 times.


Sheesh... I shoulda trained more...

HIJACK OVER!!

[Gunchie]

THREAD HIJACK!!

Hey Russ- You ride strong so don't get me wrong, but you might want to consider a granny for the moab trip. It's not that you couldn't do it without one, but you might be more comfortable and have more energy throughout the week if you did.

Keep in mind that even on the day we do the shuttle and 7,000 ft of decent, that 26 miles of trail also has 2000 ft of climbing. 2000 ft of climbing is like doing LT 15 or 20 times.


Sheesh... I shoulda trained more...

HIJACK OVER!!

Ray's right (it feels weird to say that), you should really consider a granny gear. My typical ride involves 2000 ft of climbing and I can tell you my granny gear is my best friend at times. 26 miles of downhill... Egypt doesn't sound as cool anymore...

[jimithng23]

CONTINUE HIJACK...

I went to a 2x9 on the bike I'm bringing - 24/36 with 11/34 cassette I believe.