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I need a new rear deraillier ( sp? ) I have a XT m750 but I dont know the cage size. What is the difference between a XT long cage rear der and a mid cage der.

Thanks
 

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guitarscrub said:
I need a new rear deraillier ( sp? ) I have a XT m750 but I dont know the cage size. What is the difference between a XT long cage rear der and a mid cage der.

Thanks
What chainrings are you running?
 

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ride hard take risks
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If your doing XC riding go with a long cage it will shift smoother. If you do more FR/AM i use a med cage with 11-34 rear cog & 22-32 front sprockets.
 

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dogonfr said:
If your doing XC riding go with a long cage it will shift smoother. If you do more FR/AM i use a med cage with 11-34 rear cog & 22-32 front sprockets.
Actually a shorter cage tends to shift quicker and more easily. Not really a big deal with the current ramped and contoured cassette cogs but it was with straight(er) cut teeth. Usually with three rings you could/can not use the big/big gear combos and a short cage without breaking something so it was/is not a setup for inexperienced/inattentive rider.
With a double or single chainring a shorter cage can handle the full gearing range and keep the chain tighter.
 

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shiggy said:
Actually a shorter cage tends to shift quicker and more easily. Not really a big deal with the current ramped and contoured cassette cogs but it was with straight(er) cut teeth. Usually with three rings you could/can not use the big/big gear combos and a short cage without breaking something so it was/is not a setup for inexperienced/inattentive rider.
With a double or single chainring a shorter cage can handle the full gearing range and keep the chain tighter.
I'm switching my gearie from 24/34/46 to 22/32/44. Sticking with an 11/34 cassette. (body is getting old) Can I go with a short cage rear der? or should I stick with the long cage? BTW, I never go big-F/big-R or small-F/small-R. The most cross-chain I do is big-F/4th-R or small-F/5th-R.
 

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Yea to be on the safe side go with a long cage.. XT only comes in long or medium cage models.. I had both models before with 11-32 and 44-32-22 setup and I didn't find the medium cage to be shifting any smoother or faster than the long cage. Maybe that's because I've always had XT shifters and XTR cableset... They were on two different bikes, and the only difference was the short cage bike had Deore cassette and chain while the long cage bike (my current one) has XTR chain and XT cassette.

I think cables and housing make a bigger impact on shifting quality overall.
 

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You still have a 22t difference. No change except you might be able to remove a bit of chain.
 

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I'm not sure why you need a long cage?

I run a medium cage HN XT on my 6" full suspension bike with no worries. The medium cage is shorter and gives more clearance with less chance of a stick in it. I also believe the shifting is a bit more lively with the shorter chain. I can access all cogs (11-34) in the middle chain ring and get a descent range with the small and big rings (22,44) Why promote the long cage so much? Am I missing something?
 

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All Mountain said:
I'm not sure why you need a long cage?
I run a medium cage HN XT on my 6" full suspension bike with no worries. The medium cage is shorter and gives more clearance with less chance of a stick in it. I also believe the shifting is a bit more lively with the shorter chain. I can access all cogs (11-34) in the middle chain ring and get a descent range with the small and big rings (22,44) Why promote the long cage so much? Am I missing something?
The long cage allows you to run a larger front sprocket & run in the larger rear sprocket, witch the fancy guys insist is a nono, put the pros do it when needed. The longer cage makes for a longer chain, the derailler is also a tenssioner. Also the long cage keeps the top roller away from the larger rear sprocket. I also run a mediume cage with a 11-34 rear & 22-32 front. Withe that 44T front just make shure you have enough chain slack especially if you are runing in the 34 rear & 44 front thats a long stretch.
 

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All Mountain said:
I'm not sure why you need a long cage?

I run a medium cage HN XT on my 6" full suspension bike with no worries. The medium cage is shorter and gives more clearance with less chance of a stick in it. I also believe the shifting is a bit more lively with the shorter chain. I can access all cogs (11-34) in the middle chain ring and get a descent range with the small and big rings (22,44) Why promote the long cage so much? Am I missing something?
What happens if you run the 34 cog in back and the 44 ring up front?
What happens if you run the 26, or 30 cog in the back, and the 44 ring up front,
and you fully compress that 6 inches of suspension?
There is a chance you may reach the limits of the derailleur, and start to pull
on the hanger tab, or frame.

Now some people are disciplined enough to never run these "iffy" cassette-chainring
combo's. but for most people running a triple ring set up, and a wide range cassette,
the long cage derailleur makes the most sense.
 

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All Mountain said:
I'm not sure why you need a long cage?

I run a medium cage HN XT on my 6" full suspension bike with no worries. The medium cage is shorter and gives more clearance with less chance of a stick in it. I also believe the shifting is a bit more lively with the shorter chain. I can access all cogs (11-34) in the middle chain ring and get a descent range with the small and big rings (22,44) Why promote the long cage so much? Am I missing something?
Some suspension frames will require you be very careful about chain length. Many full suspension frames have growing chainstay lengths as the suspension compresses. Even though you might have enough chain to clear the big/big combo you might not once the suspension compresses. Depending on how much this increase is you need to be careful how big you go in the back when running the big ring.

When installing a chain on a FS bike the first time I always make sure there is enough to clear the big/big ring. Then I removed the shock from one of its pivots and cycle the suspension all the way in by hand with the chain on the biggest cogs to see how the derailleur responds. If the chains reaches its limit before the suspension can reach the end then I start adding links as necessary. Its all a tradeoff. You can go safe and run the longer chain at the expense of having a limper chain on the granny or go short and have better tension and be more careful about your shifting.

The advantage of long cage is its the most "idiot proof" model in a way of speaking. You can run the chain plenty long enough to take up the slack on any combo and FS although at a slight expense in shifting crispness. Personally I usually use a medium cage were ever possible regardless of the cassette. I run the chain long enough to be towards the safe side at the expense of having it go somewhat limp on the granny/11t cog. I will absolutely never need that combo and even if I accidentally shifted into it, it wouldn't cause any damge. The chain might get dropped at worse.
 

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Upchuck said:
Can I go with a short cage rear der? or should I stick with the long cage?
Never go with a short cage unless you are absolutely sure what you're doing. Short cages are mainly for roadbikes with small ratio cassettes. Don't use them on mountain bikes unless you are running a single chainring or at most a double with a road cassette in the back about 27t max. Medium is the smallest you will typically want to consider on a MTB and long if you just don't want to think about it.
 

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I was just logging on to ask a similar question - how convenient! I'm turning my drivetrain into a 2x8 over the winter, and I'd like to use a medium cage rear derailleur if possible. I'll be using 32/42 x 11-32 with either an m950 or m952 XTR rear derailleur. Can I run the mid-cage safely?
 

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brozek said:
I was just logging on to ask a similar question - how convenient! I'm turning my drivetrain into a 2x8 over the winter, and I'd like to use a medium cage rear derailleur if possible. I'll be using 32/42 x 11-32 with either an m950 or m952 XTR rear derailleur. Can I run the mid-cage safely?
Safely is a tough one, as mentioned when crossing the 42 to the 32 you are using alot of chain, true you ar not supposed to do this we do it any way. I would say go long. You must be a very strong climber for that set up.
 

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brozek said:
I was just logging on to ask a similar question - how convenient! I'm turning my drivetrain into a 2x8 over the winter, and I'd like to use a medium cage rear derailleur if possible. I'll be using 32/42 x 11-32 with either an m950 or m952 XTR rear derailleur. Can I run the mid-cage safely?
It will be fine.
 

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Only an idiot would use 34 back and 44 front, fair dinkum. It really astounds me that some people in this thread are worried about that.... people who have to ability to fully service and modify their own bikes, provide excellent tips, yet fret about using ridiculous chain lines like a 34/44 combination? I ride a 6" suspension bike with no problems on a medium cage. Long cage was invented for newbies and is a backwards step in the advancement of shifting technology.

deoreo said:
What happens if you run the 34 cog in back and the 44 ring up front?
What happens if you run the 26, or 30 cog in the back, and the 44 ring up front,
and you fully compress that 6 inches of suspension?
There is a chance you may reach the limits of the derailleur, and start to pull
on the hanger tab, or frame.

Now some people are disciplined enough to never run these "iffy" cassette-chainring
combo's. but for most people running a triple ring set up, and a wide range cassette,
the long cage derailleur makes the most sense.
 

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All Mountain said:
Only an idiot would use 34 back and 44 front, fair dinkum. It really astounds me that some people in this thread are worried about that.... people who have to ability to fully service and modify their own bikes, provide excellent tips, yet fret about using ridiculous chain lines like a 34/44 combination? I ride a 6" suspension bike with no problems on a medium cage. Long cage was invented for newbies and is a backwards step in the advancement of shifting technology.
:rolleyes: wow - if your not interested in a reasonable answer to a question that
you ask - don't ask the question. - It's that simple.
 
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