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Short cage rear der.?

1073 Views 24 Replies 15 Participants Last post by  Beau, 
F
I see some people running dura-ace rear der.s.
Do short cage der.s last longer?
if so why don't bike companies spec them on DH/FR bikes?
Just wondering since I have been going thru rear der.s
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V
I need a rear del too and I'm going for the 105 short cage...I have few friend using them and they are pritty happy with it...and the best part is that they are 30bux new and come in black...
For DH/FR go for a short cage...
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fathead said:
I see some people running dura-ace rear der.s.
Do short cage der.s last longer?
if so why don't bike companies spec them on DH/FR bikes?
Just wondering since I have been going thru rear der.s
Click to expand...
That's what I'm running, along with a little roadie cassette. Couldn't be happier... the shifting is super tight and crisp :)

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smelly
short cage derailleurs shift much faster and they shift a lot better under pressure. i've also heard, although i don't know this as fact, that short cage derailleurs make it harder to bend the chain because it puts less lateral tension on it. like i said, that was just something i heard, but it does make sense
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C
Short cage

The short cage derailluers are lighter, need less chain, are less likly to hit things and are non-rapid rise.
Downsides are some bikes need a lot of chain (223s etc) and you can only run a 27t max rear sprocket.
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J
Ultegra

Yep, I switched from a Shimano XT short cage to a Shimano Ultegra road deraileur. The shifting is much crisper and the retrun spring keeps the chain much more taught. Also the cage is super short so I catch it on stuff alot less. I'd never use XT/XTR on my freeride bike again, road Ds are way better in my opinion. Also just switched my crapola deore shifter that come on my bighit for an SRAM. Aint tried it out yet but it seems like a good idea to me to have your shifting all with your thumb, leaves ya fingers to operate the gear levers..
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Speedub.Nate
Cyco said:
The short cage derailluers are lighter, need less chain....
Click to expand...
They need the same amount of chain as any other cage length.

But in addition to everything else you guys said, they do a good job of reducing chain slap.
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D
Brakes, right?

jungleuk said:
Also just switched my crapola deore shifter that come on my bighit for an SRAM. Aint tried it out yet but it seems like a good idea to me to have your shifting all with your thumb, leaves ya fingers to operate the gear levers..
Click to expand...
Frees up your trigger finger for the brake lever, right?
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---Matt---
Cyco said:
The short cage derailluers are lighter, need less chain, are less likly to hit things and are non-rapid rise.
Downsides are some bikes need a lot of chain (223s etc) and you can only run a 27t max rear sprocket.
Click to expand...
Are you sure about the 27t max rear sprocket? I'm running a 30t rear sprocket on my bike with a Shimano 105 derailleur and I've had no problems at all for the last year.

I thought it was a combination of the front and rear gears that determined what derailleur cage length you could use.

---Matt---
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DeeEight
Cyco said:
The short cage derailluers are lighter, need less chain, are less likly to hit things and are non-rapid rise.
Downsides are some bikes need a lot of chain (223s etc) and you can only run a 27t max rear sprocket.
Click to expand...
Actually the last part is quite false. While shimano "claims" the max cog size is a 27T its a lie. In reality they'll work fine all the way up to a 34T cog. For starters, the max cog size is based on road frames, which typically have shorter derailleur hangers (measured from axle) than mtb frames. Second. If they told the truth, nobody would waste money on their heavier MTB derailleurs.
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man w/ one hand
90 degree cable bend @ derailluer?????

Slack said:
That's what I'm running, along with a little roadie cassette. Couldn't be happier... the shifting is super tight and crisp :)
Click to expand...
Are you still runnin' your cable like that pic shows? Looks like the housing is making about a 90 degree turn @ the derailluer. If its workin'....don't fix it.
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COmtbiker12
man w/ one hand said:
Are you still runnin' your cable like that pic shows? Looks like the housing is making about a 90 degree turn @ the derailluer. If its workin'....don't fix it.
Click to expand...
It doesnt look like the housing is even going into the barrel adjuster thing there either.
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R
tooth capacity

I agree with the other guys who are running the larger cassette. I have run 32 tooth cassettes on 2 differant bikes with no problems. The main purpose of the long arm derailleurs is because they have to take up so much chainslack when running a triple chainring on the front. Since DH bike only run a single chainring the short cage works xlnt.
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man w/ one hand said:
Are you still runnin' your cable like that pic shows? Looks like the housing is making about a 90 degree turn @ the derailluer. If its workin'....don't fix it.
Click to expand...
Actually, I was having a lot of problems till I added the Rollamajig. That was the secret ($10) ingredient :D
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B
Ummmm?

Speedüb Nate said:
They need the same amount of chain as any other cage length.
Click to expand...
Think about that one.

Beau
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J
umm yeah

damion said:
Frees up your trigger finger for the brake lever, right?
Click to expand...
Sorry I dunno why I typed that.. I meant it leaves your fingers free to operate the BRAKE levers.. not the gear levers :)
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Speedub.Nate
Beau said:
Think about that one.
Click to expand...
Chain length is determined by wrapping the chain around the largest cog and the largest ring, independant of the rear derailleur.
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B
Absolutly..........

Speedüb Nate said:
Chain length is determined by wrapping the chain around the largest cog and the largest ring, independant of the rear derailleur.
Click to expand...
......Wrong. Proper chain length is determined by putting the chain in the smallest cog, and smallest chainring. When the der. cage is parallel to the ground, that is your proper chain length. If you want to see how short you can get your chain, you do it using the described method. Shifting performance will be compromised though and your "B" limiter screw will be worthless.

As far as the chain length goes, a short cage chain will use less links than a long cage rear der.

Beau
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Beau said:
......Wrong. Proper chain length is determined by putting the chain in the smallest cog, and smallest chainring. When the der. cage is parallel to the ground, that is your proper chain length. If you want to see how short you can get your chain, you do it using the described method. Shifting performance will be compromised though and your "B" limiter screw will be worthless.

As far as the chain length goes, a short cage chain will use less links than a long cage rear der.

Beau
Click to expand...
http://www.parktool.com/repair_help/FAQchainlength.shtml

Same thing in my Barnetts manual. The large >>> large has worked well everytime I've used it.
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Speedub.Nate
Beau said:
......Wrong. Proper chain length is determined by putting the chain in the smallest cog, and smallest chainring. When the der. cage is parallel to the ground, that is your proper chain length. If you want to see how short you can get your chain, you do it using the described method. Shifting performance will be compromised though and your "B" limiter screw will be worthless.

As far as the chain length goes, a short cage chain will use less links than a long cage rear der.
Click to expand...
Sorry Beau, I'm not familiar with the "parallel to the ground" method, but perhaps you can enlighten us.

The two methods I'm familiar with are these:


These are both suggested by Shimano. The first (the big-big method) is also suggested by SRAM. The second method I've seen suggested for drivetrains with narrower cassette spreads and wider chainring spreads, such as road bikes.

It's true that both are assuming double or triple chainring combos, but I've run the big-big method on a 1x9 drivetrains and have not experienced the "compromised shifting" you warn about.
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