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  1. #1
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    Idea! Shimano XTR M950 Derailleur Overhaul

    xtrBlock1.jpg

    The XTR rear derailleur (1) is fairly simple to service. With the derailleur removed from the frame, first remove the two pulley wheels (2/3); the upper ‘G’ pulley (2/4) and the narrow lower (3/5). The ‘G’ pulley has a moveable centre which allows the introduction of grease into the bearings. The aluminium seals appear quite effective at keeping grit out, so I usually just push the centre until there’s sufficient space to press some grease in, then reverse the pulley and do the same from the other side. Depending on the condition, I may clean the bearings out with a degreaser, which in turn is cleared out with Isopropyl Alcohol and compressed air, before applying fresh grease.
    If you’re just topping up the grease, clean the pulley thoroughly so that the body is free of any dirt before you open the bearing. Only a small amount of grease is required; too much will create its own excess friction inside the bearing. I use Pedro’s Syn Grease for all my bicycle bearings.
    As you can see from the picture (5) the sealed bearing on the narrow pulley differs slightly, making it possible to remove the bearing seal for servicing.
    NB. Take great care when removing the seal from a sealed bearing. If the seal is bent or the edges are damaged you may have difficulty re-fitting or prevent the seals from working effectively when in use. I use a very small jeweller’s screwdriver to prise the bearing seals out and press them back in with a clean cotton bud.
    The bearing from the narrow pulley can easily have the old grease completely removed with degreaser. Try not to rotate the bearings too much when the grease has been removed. Same as with the G pulley; clean the pulley body before you open the bearing and go easy on the fresh grease.

    Remove the barrel adjuster mechanism from the derailleur body by unscrewing it, clean and put to one side.

    xtrBlock2.jpg

    The H and L parameter screws can also be removed (6/7), along with the plastic seat which they thread through.

    The cage plate of the XTR is also removable, allowing access to the cage spring assembly. Picture (8) shows the Philips-head screwdriver fitting on the top of the cage stop. To remove, push the cage anti-clockwise from the body until you can get your screwdriver in. This can be done with one hand, but make sure you have enough grip to keep the cage still. When the cage stop has been removed, slowly allow the spring to relax, pulling the cage clockwise and past the point that the cage stop previously dictated until it points ‘forward’ (9).

    With the spring relaxed, loosen the cage retaining bolt with a 5mm Allen key (10). Remember that the cage is still under a small amount of pressure from the spring, so try to keep a hold of both the cage and the body. The bolt is mounted in the cage and will only protrude 2-3mm when unscrewed.

    Now for a bit that has perplexed me slightly. On the M950 there are two holes in the cage for mounting the spring into (11). If you look straight on at the cage as if it were fitted to the frame, there is a hole at 12 o’clock and a hole at 1 o’clock. I bought my M950 used and when I first opened it up didn’t pay attention to which of these holes the spring was mounted into originally (well done, I know!). Anyway, I’ve come to ascertain that there is more spring tension when the spring is seated in the 12 o’clock hole and, perhaps as my derailleur is a few year’s old, it seems to work better in the higher tension setting. I’ve done some searching and checked the Shimano site but haven’t been able to get any definitive information, so I’m entirely open to further information/confirmation and will update this guide accordingly.

    So back to it; remember to take note of the position of the spring when you open the cage bolt assembly! Remove the cage from the body, the plastic ring seal and finally the spring. You’ll notice that the tips of the spring are not the same; the tip that sits in the body is longer than the tip that sits in the cage.


    The frame mounting bolt can be removed by first prising the retaining clip. To get the clip off, place the flat face of a screwdriver against the threads of the bolt and lever the clip slowly out (12). You could but something in here to protect the threads (I'll use a small piece of inner tube when I refit), but caution should be protection enough. The stopper plate is under a fair amount of pressure from the spring, so be prepared for it to spin clockwise once the retaining clip is removed (13) (it may not happen immediately!). With the stopper plate out of the way, the spring can be removed (14).
    The mounting bolt can now be pushed through from the inside and the rubber ‘o’ ring carefully prised from the outside of the derailleur body with a fine point. There is also a smaller ‘o’ ring on the bolt itself (17).

    xtrBlock4.jpg

    You should now have a completely dismantled derailleur (15/18). The jockeys should already have been cleaned and re-greased by this point. All of the other small parts and the derailleur body can be washed with degreaser, the latter also being rinsed under a hot tap. To make sure everything is rinsed well clean of degreaser, I'll use Isopropyl Alcohol and then dry it all thoroughly. Compressed air, or just blowing, will get any water out of the derailleur pivots/body and folded tissue paper will clear out the spring chambers.

    Never having had the experience of dismantling a new derailleur, I’ve had to use a certain amount of guesswork as to where fresh grease should be applied. My grease of choice for this job is Pedro’s Syn.
    I’ll give both springs enough grease to have them completely coated in a thin layer, with an extra dab on each spring tip. Whilst there is some need on the springs for lubrication to reduce friction, it appears to me that the greater need is to stop corrosion from the almost inevitable ingress of water, particularly in the main body spring where there is no seal between the cage plate, stopper or derailleur body.
    I run a small rim of grease under the outer ‘O’ ring and also inside the barrel of the body that the bolt will run through. This should be enough to lubricate the small ‘O’ ring seal when the bolt is replaced. With regular cleaning in mind, I’ll just run an extra line of grease around the rim of the body-spring chamber and wipe away any visible excess when the stopper is refitted, which leads me nicely to the task of refitting it…
    If you refer back to picture (13), this is the position of the stopper in its ‘rested’ state. Our job here is to turn it anti-clockwise until the stopper has cleared the corresponding ridge on the body and been depressed far enough to refit the retaining ‘U’ clip. The first time I did this it went on first time, no problem. The second time I must have spent ten minutes trying to do the same thing. With the body adjust screw fully extended away from the stopper to give you a little extra leverage, the trick is to keep pressure on the outer edge of the bolt so that it is kept fully inserted, then, in a quick, ‘snap’ movement, twist the stopper past the ridge and push it in to place against the body. At this point, keep a good compression on the assembly or the stopper may spring up again. Have the ‘U’ clip to hand so you can push it into its seat in the bolt, then use a pair of stub-nose pliers to press it all the way in. I have a small piece of inner tube handy to place over the thread of the bolt and protect it from the teeth of the pliers.
    If you’re finding it a struggle to get the stopper back into place by hand, a pair of pliers can be used. The ‘twist-push’ movement is the same; you’re just taking some of the pressure off of your fingers. Be aware that the pliers can easily slip and take the necessary precautions to protect the derailleur body and also your digits.

    For the rest of the derailleur, reassembly is the reverse of disassembly. In addition to the grease on the spring, I’ll also run some around the rim of the chamber on the cage spring, before replacing the plastic seal, and then a thin film around the outside of the seal. The bolt and spacer in the cage spring can also have a light coat of grease, although you may also choose to apply a medium (Loctite 243) thread lock to the tip of this bolt.
    It's also worth applying some grease to the H and L limit adjustment screws to help ward off corrosion. Don't forget that your H and L screws are now completely out of adjustment.

    When both springs/assemblies are refitted, use a cloth or tissue with some Isopropyl Alcohol on to wipe away any excess grease from the derailleur body.

    Lubing the pivots on any derailleur is really a matter of environment. During dry spells I don't put any additional lube on the pivots, spring or spring mounts as it'll attract more dirt than it would otherwise. If it's wet, or I'm expecting water where I ride, then I'll apply a little Finish Line Dry Teflon lube to the pivots, spring and spring-ends. After leaving the lube for 10 minutes or so to soak in and dry, I'll wipe any spill/excess off of the body with alcohol.
    Last edited by SteveUK; 12-08-2006 at 02:13 PM.
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  2. #2
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    Wow!

    Awesome pictorial!

  3. #3
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    maniacal..i love it...great write up...haven't seen anything better...you need to write a book Steve
    "He can make even a global summit meeting seem like a kegger." M. Dowd, NY Times, 19 July 2006

  4. #4
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    makes me want to do an unnecessary overhaul to my derailleurs!
    every thread needs an uploaded image of one kind or another.

  5. #5
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    If you refer back to picture (13), this is the position of the stopper in its ‘rested’ state. Our job here is to turn it anti-clockwise until the stopper has cleared the corresponding ridge on the body and been depressed far enough to refit the retaining ‘U’ clip. The first time I did this it went on first time, no problem. The second time I must have spent ten minutes trying to do the same thing. With the body adjust screw fully extended away from the stopper to give you a little extra leverage, the trick is to keep pressure on the outer edge of the bolt so that it is kept fully inserted, then, in a quick, ‘snap’ movement, twist the stopper past the ridge and push it in to place against the body. At this point, keep a good compression on the assembly or the stopper may spring up again. Have the ‘U’ clip to hand so you can push it into its seat in the bolt, then use a pair of stub-nose pliers to press it all the way in. I have a small piece of inner tube handy to place over the thread of the bolt and protect it from the teeth of the pliers.
    I just rebuilt my XTR deraileur and this was, by far, the most difficult part. Messing with those spring action sections takes a little getting used to. Thanks for the excellent post. I referenced it (and beer) multiple times while doing mine. I was on the verge of buying a new deraileur because it was in such bad shape. Now it's just like new

    Will you be doing a front Shimano XTR deraileur tutorial anytime soon?

    Thanks!

    /gC

  6. #6
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    qoute [Now for a bit that has perplexed me slightly. On the M950 there are two holes in the cage for mounting the spring into (11). If you look straight on at the cage as if it were fitted to the frame, there is a hole at 12 o’clock and a hole at 1 o’clock. I bought my M950 used and when I first opened it up didn’t pay attention to which of these holes the spring was mounted into originally (well done, I know!). Anyway, I’ve come to ascertain that there is more spring tension when the spring is seated in the 12 o’clock hole and, perhaps as my derailleur is a few year’s old, it seems to work better in the higher tension setting. I’ve done some searching and checked the Shimano site but haven’t been able to get any definitive information, so I’m entirely open to further information/confirmation and will update this guide accordingly.]

    I have found that most of the shimano rears have two spring adjustments as you described. Stock they are set on the lighter tension. I find that I prefer how they work on with the heavier spring tension. So all of my shimano bikes I have changed the spring tension.

    Mike

  7. #7
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    "I have found that most of the shimano rears have two spring adjustments as you described."

    How do you get the cage assembly off on other derailleurs? In my experience, only the XTR has a removeable cage bolt (pic 10) and cage stop pin (pic 8).
    Last edited by SteveUK; 03-04-2007 at 06:52 AM.
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  8. #8
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    Quote Originally Posted by SteveUK
    "I have found that most of the shimano rears have two spring adjustments as you described."

    How do you get the cage assembly off on other derailleurs? In my experience, only the XTR has a removeable cage bolt (pic 10) and cage stop pin (pic 8).
    I took several photos of a deore rear. This second photo shows the bolt to remove to remove the cage. The last photo shows the two holes, one at the 5 o clock position and the other at the 6 o clock position.

    Mike

  9. #9
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    Could you post the photos?

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    ok I dont know why it did not upload my photos with the last post but I am trying again.
    deore rear 1.jpg
    deore rear 3.jpg
    The 3rd photo shows the holes at the 5 and 6 oclock positions. This allows the spring tension to be adjusted.
    deore rear 4.jpg
    Sorry about the photos not coming through in the previous post.
    Last edited by Mac Attack II; 03-04-2007 at 02:17 PM.

  11. #11
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    Nice one, cheers. What age is the mech? I have an old (maybe 2001) Deore lying around and also have an 06 XT on my Big Hit and neither of them have the facility to remove the cage bolt. Also, how do you get the stop ridge on the body past the stop on the cage to reinstall the cage to the body?

    (Would you mind reducing the image size on your pics? Anything over 800 pixels and the text in the XTR guide and subsequent posts gets all screwed up, at least it will on some browsers. Cheers)

  12. #12
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    Quote Originally Posted by Mac Attack II
    ok I dont know why it did not upload my photos with the last post but I am trying again.

    The 3rd photo shows the holes at the 5 and 6 oclock positions. This allows the spring tension to be adjusted.

    Sorry about the photos not coming through in the previous post.

    Mike

    COOL PICS. does the XT have the same holes? also how difficult is it to switch from the default setting to the tighter setting? i don't wanna take it apart and realize i need a special tool to rebuild it...
    every thread needs an uploaded image of one kind or another.

  13. #13
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    [ATTACH][/ATTACH]
    Quote Originally Posted by SteveUK
    Nice one, cheers. What age is the mech? I have an old (maybe 2001) Deore lying around and also have an 06 XT on my Big Hit and neither of them have the facility to remove the cage bolt. Also, how do you get the stop ridge on the body past the stop on the cage to reinstall the cage to the body?

    (Would you mind reducing the image size on your pics? Anything over 800 pixels and the text in the XTR guide and subsequent posts gets all screwed up, at least it will on some browsers. Cheers)
    I am going to try to go step by step for this Deore. I have looked at all of my bikes from my 1996 xt to my 06 xtr and they all have removable cages.
    d2.jpg
    1st photo: Remove the retaining bolt with a 2mm hex driver.
    d3.jpg
    2nd photo: Pull the cage away from the body. So the stop pin clears the boss on the body. Remove the spring and the location of the hole that the spring attaches to the cage. Reinstall the spring into the body making sure to catch the hole in the body with the spring.
    d4.jpg
    3th photo: Rotate cage so that the pin clears the boss on the body. There will be noticably more tension on the cage as you do this.
    d5.jpg
    4th photo: Push the cage back to the body.
    d6.jpg
    5th photo: While holding the cage and body together, put the retaining bolt back in place. The retaining bolt should slide in easily if it does not try moving the cage and body a bit. The first time I did this it took me a couple of trys to get the retaining bolt to easily slide in.

    As a side note: Last year I had my first introduction to XTR and hated it. I had a very hard time getting it adjusted so it would shift as well as my older xt stuff. I am not sure why I stayed with the XTR for so long, but when I turned up the spring tension it was like a different derailure and now I LOVE it.
    Last edited by Mac Attack II; 03-04-2007 at 01:52 PM.

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    That is excellent information, Mike, cheers. I'll incorporate this into my Basic Maintenance guide.

    I realise that it's a bit of a pain to reduce the size and repost the first set of pictures (post #10), but they make it impossible to follow the XTR guide without scrolling. I'm not asking you to remove them, but I would really appreciate it if you could reduce their size. Cheers.

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    Quote Originally Posted by SteveUK
    That is excellent information, Mike, cheers. I'll incorporate this into my Basic Maintenance guide.

    I realise that it's a bit of a pain to reduce the size and repost the first set of pictures (post #10), but they make it impossible to follow the XTR guide without scrolling. I'm not asking you to remove them, but I would really appreciate it if you could reduce their size. Cheers.
    I reduced the size of the pics in post #10. Did this fix it for your viewer?

    Mike

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    Hey Mike,

    The XTR guide is based on text and pictures with a maximim width of 800 pixels. Where I have a row of pictures, it's actually just one image of 800 pixels in width, which allows me to keep the text and the pictures in an even block, and therefore easier to follow. I don't know how many browsers this is a problem with, some will automatically keep the page to a maximum size, so it's not an issue. Because I try to make my guides as accessable as possible to everyone, I just play it safe and limit my pictures to 800 pixels.
    The second group of pictures you've posted are great; they're in a single column. The one's in #10 are still in a row of three and stretching the thread. Thanks for your cooperation, I really do appreciate it.

    Steve

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    Job done, Mike. Really, thanks very much, and thanks again for the addition to the thread.
    Good dirt,

    Steve

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    Quote Originally Posted by SteveUK
    Job done, Mike. Really, thanks very much, and thanks again for the addition to the thread.
    Good dirt,

    Steve
    Hi Steve,

    I thought I would correct myself a bit. I was working on one of my road bikes a couple of days ago and decided to take apart the Sora rear derailleur. It does not have multiple holes for the spring tension. But I did think how it came apart was pretty cool and worth taking some pictures of.

    Dirty Sora Derailleur. My road bikes should get half as much attention as my mountain bikes.
    sora1.jpg

    This photo shows the access cover. It is a little marked up because I took the photo after I had taken it apart and put it back together. Now that I did it once I can say that the right way to take it apart would be to equally pry up the cover from both sides. This makes the cover very easy to remove.
    sora2.jpg

    This picture shows what the inside of the access cover looks like.
    sora3.jpg

    This photo shows the E-clip removed. The trick to taking this derailleur apart is first rotating the E-clip so that the open end is aligned with the opening. Then use two screwdrivers to push the E-clip into the derailleur. After the E-clip is pushed in the cage can be removed from the body.
    sora4.jpg

    This picture shows the single hole for the spring.in the cage. The body also has a single hole. So this derailleur does not have the spwing adjustment like the other two in this thread.
    sora5.jpg

  19. #19
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    Quote Originally Posted by gateCrasher
    I just rebuilt my XTR deraileur and this was, by far, the most difficult part. Messing with those spring action sections takes a little getting used to. Thanks for the excellent post. I referenced it (and beer) multiple times while doing mine. I was on the verge of buying a new deraileur because it was in such bad shape. Now it's just like new

    Will you be doing a front Shimano XTR deraileur tutorial anytime soon?

    Thanks!

    /gC
    I just overhauled the main body pivot in mine and I was having difficulty with this part as well. I spent a good 30 minutes trying to reassemble it and every time it got close, the spring would unwind. Finally, I took the spring out and flipped it around, I got it on the first try.

    So if anyone is having trouble, flip the spring around, evidently the spring tip is slightly longer on one side.
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  20. #20
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    "So if anyone is having trouble, flip the spring around, evidently the spring tip is slightly longer on one side."

    Do you think that the spring may be designed that way for a reason?

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    !!!!!! I just figured out an easy way to get the spring back on !!!!! I was having a lot of trouble on my M952, I could get the old spring back on but not the new one because it has so much tension. I screwed my derailleur hangar part way on to the bolt and used that as a lever to turn it into place and then tightened it the whole way down. Once you are there, back off just a little to put in the clip, you may have to pry it a wee bit so be careful and then take the hangar off. I struggled for over an hour before I thought of this and it was quite easy then. Hopefully this will save someone in the future a lot of trouble. Peace

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    This may be a dumb question, but......

    .....based on the above info, what is preventing someone from removing a long cage and replacing with a shorter cage.

    For example, I have the same Deore RD-M511 derailleur with the long cage as above. I also have an XT RD-M750 short cage derailleur. I've been wanting to get a Shimano short cage derailleur and didn't want to shell out the $$$$$ for a Saint, can I simply use the short cage from the M750 on the M511??
    No blogs here, nothing special.....I just like to ride my bike.

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