Silly me - need help indexing....

stubobby

So..... decided to upgrade my slx shifter and got myself M8000 xt shifter and new inner cables.....

and after several hours and video watching I simply cannot get my shifter to change smoothly and index properly......

I have checked and rechecked the H/L screws and played about till i'm going mental - but i just cant get a smooth or consistent shift.... i cant really tell if the hanger or actual derailleur is bent/broken or an issue - BUT it all seems ok.....

my setup is

M8000 rear derailleur

2 front sprockets

M7000 11 speed cassette

bike is around 7 years old with moderate use

any pointers well appreciated

thanks

The Rookie

H and L screws are only there for safety and have ZERO impact on any shift not involving the highest and lowest gears. in between it's all about correct alignment and cable tension.

The best guide for indexing is IMO from Parktool.

https://www.youtube.com/watch?v=UkZxPIZ1ngY

Obvious thing to check is

1/ Is the cable running smoothly

2/ is the mech moving freely on the pivots.

You can check that by having the rear wheel out the bike, shifting to a lower gear and then releasing it 2 two gears higher, if you can then move the mech cage OUT by hand it wasn't moving freely (so one of the above is an issue) and that will always drive you mad trying to index it!

trevor.hall12

Change outer casings as well as the cable ,if it still dosnt index it's the derailler itself or the hanger .

Check for any play in the derailler and the clutch is working properly ,internals for tge clutch are cheap and easy to change

While the chain is off check it pivots OK where it mounts to the hanger ,Shimano rear derailers get stiff at the b limit spring and it can be serviced too for a few quid

If all is well there it's the hanger

steve_sordy

I know how to index gears, it's not rocket science, but it can seem like an art when you watch someone who knows what they are doing.

Whenever I have been foxed by the usual procedures that have always worked before then it has always been these:

# The gear cables need renewing. Typically this is manifested by gears moving to larger gears OK, but not dropping down smoothly. Your thumb is nice and strong, much stronger than the mech return spring. Sticky shifting. Most indexing problems are relieved by new cables.

# 11 or 12 speed. They just need more care than the 8-10 speed stuff. After all, the gaps between the gears are smaller, so the indexing set up needs to be more precise.

#1x. These tend to have a wide spread of gears on the cassette, even 10-speeds can have them. See next one for what follows.

# Usually, the 11 or 12 speed comes with a big dinner plate gear on the cassette. This requires a longer and therefore lower hanging mech arm, which is more in harms way than before. When it gets knocked there is more leverage to exert on the mech and the mech hanger. Stuff you used to ride through on 8-10 speed gears suddenly starts hitting your mech. Mostly you will not notice because it swings out of the way, but the impact was felt by the mech and the mech hanger and can manifest as poor shifting.

# A build up of crushed vegetation in the mech. It will be black due to the oil and decay, it will be small, and it will look like part of the mech. But it stops the mech from working properly. Remove the mech and clean it with hot water, degreaser and a stiff brush. Once dry, re-lube the mech and it will work like new, or at least as good as it can!

If you are certain that it's not the cables, a dirty mech, or even your own poor set up, then that leaves only one candidate:

# Mech hanger alignment. In my years of mtb I never once required my mech hanger to be aligned, but once I went 11 and 12 speed, I had to have it done three times in quick succession by the LBS (I had two bikes then, one with 1x11 and one with 1x12. It was cheap to do, but disruptive as I didn't have the kit to do it myself. The tool, which is also a gauge, checks whether the mech hanger has been bent, or even if the mech itself has been bent. There was no visible damage in all cases. The only indicator was sub par and unfixable shifting. The same bit of kit is also the tool that corrects the misalignment. Google "mech hanger alignment tool". The gold standard is by Park Tool, but there are cheaper ones. Start by looking at the Park Tool ones and watch the video on how to use them, then look for cheaper ones if you are on a budget. They all work well.

I have used a mech hanger alignment tool to set up a mech that had previously been severely bent when it sucked up a stick. I dismanted the mech, then hammered out the bends and rebuilt it. I tested it to see it worked and now it sits as a spare in my cabinet. :)