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I was running a RD-M7000 dérailleur on my Scott E-Genius 730 and I recently received some good advice here that the Deore RD-M6000 is a drop-in replacement. I have now purchased and fitted that, but the topmost jockey wheel appears to be touching, or at least far too close, to the cassette. As a result I get a lot of unacceptable gear clatter in most rear gear selections (I also can't reach the highest gear, but one step at a time).

Here is an overview of the cassette, dérailleur, chain and crank.

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I believe I've taken some six links out of the standard chain, and I think it is probably still too long. However, I don't think this is the problem. If I pull down on the main lower section of chain (to emulate a shorter chain), it pulls the lower jockey wheel closer to the crank, but it does not at all move the upper jockey wheel away from the cassette. I think that is what I need to fix.

Here is a closer view:

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You can see here that the upper jockey is far too close to the cassette.

Finally here is what I want to achieve - something to reorient the dérailleur angle so the upper jockey is distanced from the cassette:

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I have a suspicion I know what is wrong, though I don't know how to fix it. In the first two pictures a red connecting mount on the bike is shown. There is a black connector piece attached to that, and finally the dérailleur is attached to that. What I notice is that the two connector brackets form an angle of some 15° from each other. However in my previous post (see first link) they are some 85° from each other, and note: it is the old bracket. Not a new matching model - the actual old one from the old photo.

However I have slackened the internal hex key nut off, and tried to move the dérailleur clockwise around this pivot point, but something is preventing this bracket from travelling further. I wonder, could I have installed it back to front?

  • How many teeth are on your biggest cassette cog ? Looks like about 40 ? The specs say iit can run a 42 tooth bike.shimano.com/en-NZ/product/component/deore-m6000/… so do you need the red adapter ? – Criggie Jun 17 at 1:56
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    Thanks @Criggie - I have 36 on the largest cassette cog. The red adapter was OEM fit - I'm basically trying to do a like for like swap. Here is the original dérailleur in place (see pic). – halfer Jun 17 at 9:31
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    (The dérailleur is a slightly different model because the original was quite hard to obtain. However my information at the moment is they are of the same physical dimensions and will behave in the same manner). – halfer Jun 17 at 9:41
  • Based on the specs of the mech, and that excellent answer, I wonder if the red adapter is doing you mischief. I'd be tempted to try without it, and if everything works in the garage then try a test ride. – Criggie Jun 17 at 10:46
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On these Shadow derailleurs, there is a tab that must rest on the bottom lip of the derailleur hangar. (I'll note at this point that you must use the correct hangar for your bike. "Almost" like it or "derailleur has the same angle" when an incorrect hangar is used doesn't cut it. Millimeter differences create big changes in the workings of these things. Consider how a few rotations of a fine threaded Barrell adjuster can change a whole gear. Or if the cable is not routed just right--like say misses a small little leverage tab, the derailleur won't be able to get onto certain gears.). If the little tab isn't touching the lip of the hangar, shifting will be compromised. In addition, I see your derailleur's cable is not properly seated into the derailleur's housing. That will eventually cause excess friction and poor shifting. While one doesnt necessarily need ferrule at this point on the external (the derailleurs cable seat/stop can act as one)—a sealed ferrule will prevent easy contamination of the inner cable at this vulnerable spot. Full Suspension bikes utilize the aluminum ferrule to help prevent ghost shifting when the suspension moves.

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Note the things I'm talking about on these pics of my XT Shadow der. My cassette is an 11-36. Up front I have a 2x crankset, 38-28, and I'm on the big ring. You have to hold the derailleur just so on install so that tab gets seated in the proper spot. In this Dealer's Manual from Shimano these issues are discussed.

Finally. When a rear derailleur and it's cable are installed correctly, manipulating the B-screw moves the upper jockey wheel closer to or away from the cassette. Clockwise rotation moves the screw in and the jockey wheel away from the cassette; anti-clockwise moves the jockey wheel closer to the cassette. See photo for location and a view of the proper distance the jockey wheel should ride from the cassette.

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  • This is great, Jeff - many thanks. My "double hangar" (the metallic-effect device, plus the black section connected to it) appears also to be wrong - your first photo helps confirm that. On your hangar you have two circular disks (one of which is a hex key) and they are mostly horizontally in line - mine are some 45 degrees on the diagonal. If I can reorient this then the whole body of the dérailleur will move away from the cassette, including the top jockey wheel. – halfer Jun 17 at 9:48
  • I have been fiddling with the grub screws, but I appreciate your better description of what they actually do. I've historically thought of them as setting the top and bottom gear "stops" to prevent the chain falling off either edge of the cassette. However, gear adjustment is something I've long avoided, having got myself into a frustrating pickle so many times - I nearly always try to get someone else to do it. Not so easy in lockdown... – halfer Jun 17 at 9:49
  • @halfer There's actually three screws. Two are limit screws doing the function you described, while the third (the B screw) adjusts the distance between the guide pulley and the cassette. – MaplePanda Jun 17 at 19:39
  • @halfer As MaplePanda describes and you also correctly noted, the other two "grub" screws are the high and low limit set screws. Once these are set on installment, there is little reason to change them unless there are changes to the hub that changes the cassette location laterally. This situation would be rare. Indexing and tweaking of any shifting issues is done by manipulating the Barrell adjuster at the shifter (Shadow derailleur's do not have barrel adjusters like older model derailleurs). – Jeff Jun 18 at 19:25
  • @halfer I'm unable to do the research myself at the moment, but you should determine if your bike is compatible to have the derailleur connected via "direct mount." Essentially you will remove the tail of the derailleur which now contains the bolt that connects to the der hangar and use the next bolt (the one now connecting the "tail") to connect der to the bike's direct mount hangar. Benefits are a bit simpler install. The der gets tucked in more behind the cassette and out of harm's way. Shifting may be a touch smoother. Direct mount takes full advantage of the "Shadow" design. – Jeff Jun 18 at 19:35

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