Forum home Road cycling forum Workshop

Indexing Issues with new touring build

hububallihububalli Posts: 26
edited May 2016 in Workshop
After following all the advice there already is here about touring setups, I built the following:

105 STI triple 10 speed shiters
105 triple front mech
Deore M590 9 speed triple 48.36.26t chainset (with 2 spacers on left side, 1 on right)

Tiagra 10 speed 11-32 cassette
Deore RD-M591 long cage 9 speed rear mech

The front shifts fine but at the back I cannot get the indexing right. I have the never ending cycle of when in the lowest gear and you try to shift it doesn't go down a cog, so I loosen the cable a little until that shifts. Then in the highest gear the cable is now to loose to shift up a gear so I tighten it a little till it works and then I am back where I started.

Everything on the bike, including the frame is new. I got the rear mech second hand though, although it was sold as near new, which it certain looks like. Do you think it is the rear mech? I was thinking about upgrading to an XT M771 but thought I would ask here first in case there is something I can do.



  • If I remember, Shimano road & MTB groups aren't interchangeable - presumably using your Deore mech with 105 shifters is the issue.

    I'd expect a 105 or Tiagra long-cage rear mech would be pretty inexpensive though.
  • hububallihububalli Posts: 26
    From what I read, Shimano Road / MTB parts are interchangeable up to 9 speed. 10 speed MTB has a different ratio so cannot be used. I don't think there are any Shimano road mechs with a big enough capacity. They do not do long cage versions anymore it seems, they only do the GS.

    I have a capacity of 43 teeth. The 105 GS rear mech has a total capacity of 40 so its not quite big enough.
  • mercia_manmercia_man Posts: 1,365
    There's plenty of advice and discussion on this topic on the CTC, now Cycling UK, forum. It would appear from what I have read that 10-speed road is not compatible with 10-speed MTB. The get around appears to be what you have done - using a nine-speed MTB RD with 10-speed road shifter.

    So it sounds like your problem with indexing may be down to technique. Here's a summary of what says:

    Shift the derailleur all the way down to smallest cog, screw barrel adjuster right in and turn H limit screw so upper pulley wheel is directly under the cog.

    Tighten cable by unscrewing clamping screw on RD, pull cable taut and retighten.

    Shift to fourth or fifth cog and turn barrel adjuster so upper pulley wheel is lined up under correct cog. You may find it easier to do without the chain fitted. According to the article I'm reading it is generally best with Shimano for the wheel to be slightly inboard of the cog. Do practice shifts to ensure it's changing correctly.

    Shift onto largest cog and adjust the limit screw L so pulley wheel lines up with largest cog.

    Adjust B-tension screw on RD so upper wheel is as close as possible to largest cog without dragging.

    I apologise if you have already done all this but I have found that following this process in order rather than simply turning the barrel adjuster in or out is the answer to getting your indexing perfect. Problems sometimes result from slackness in the cable - it must be taut when you are on the smallest cog.
  • hububallihububalli Posts: 26
    This is different from the process I use so I will give it a try, thanks. I like the step of adjusting the barrel mid cassette, makes a lot of sense. I will have a look at the Cycling UK forums too!

    I usually screw the barrel adjuster all the way in then out a turn, set the H, check for slack in cable, shift to largest then slacken L till you get rubbing, then turn it back half a turn. I run through the cassette a few times with a slight adjustment on the barrel if needed. Works on my road bikes but no luck on this build.
  • dj58dj58 Posts: 2,073
    The new Tiagra 4700 RD GS model will take 34T low sprocket, unfortunately for you it is not backwards compatible with your 5700 10 speed STI. I'd buy a new RD as if the S.H. one is damaged in some unseen way that could be your problem.

    IIRC there was a post a couple of years back where the poster had bought a nearly new RD and when he had fitted it, it exhibited the same symptoms as you describe. He bought a new RD the same type/model and it index perfectly, his LBS said that the cage was out of alignment I think. Also check your inner/outer cable loop leading to the RD is functioning correctly.
  • hububallihububalli Posts: 26
    I nearly bought one of those until I noticed all the reviews from annoyed people saying it is not compatible. Seems a strange thing to do, not making all the 10 speed road components compatible.

    I will try doing the indexing again tomorrow and will check the cable is not catching somewhere. If it doesn't work I will go pickup a new XT mech instead. That post you mentioned does make it sound like I have the same situation here.
  • AK_jnrAK_jnr Posts: 717
    Hanger alignment.
  • Nick PayneNick Payne Posts: 288
    Mercia Man wrote:
    It would appear from what I have read that 10-speed road is not compatible with 10-speed MTB.
    According to the OP, he/she is using 10s road shifters and cassette with 9s MTB rear derailleur. That combination is perfectly compatible and should change without problems - I have it running on one of my bikes. The problem must be due to something else - e.g. is the cable inner clamped on the correct side of the pinch bolt on the RD?
  • hububallihububalli Posts: 26
    I tried Mercia Man's suggestion and its better but still doing it. I decided to order a hanger alignment tool before going for the new RD as it seemed like a good excuse to get a new tool for the collection! I think it would be a good thing to have on hand too.

    I just assumed that as the bike is new, the hanger would be fine but there is really no reason to assume that.

    The cable is aligned with the groove in the RD which makes a straight line to the barrel.
  • AK_jnrAK_jnr Posts: 717
    Yeah I would of thought that too until I saw videos of a mechanic showing how far out one was on a brand new frame.
    Mine was out by 10mm. Night and day difference.
  • hububallihububalli Posts: 26
    I think I saw the same, or a similar video on youtube after you suggested it might be the hanger.

    So I got the tool, and it was about 2cm off. Got that all aligned and as you said the difference is huge but the indexing is still not quite right so I have ordered a new mech. I went for the XT M772 9 speed.

    I also ordered a new hanger as after all that moving around it feels a bit soft. It is a lot easier to bend than it was to start with so think I have stressed out the aluminium too much.
  • AK_jnrAK_jnr Posts: 717
    My indexing seems to be slipping back to how it was before the alignment as well so I think I need a new hanger too. Maybe being bent the wrong way so long is making it gradually ease back there
  • hububallihububalli Posts: 26
    To finish this topic off, I got my new hanger (not sure if I really needed it but better to be safe than sorry!) and my new XT M771 mech and everything is now working fine. Adjusting the hanger made a big difference and the new mech just made it perfect.

    I spent a few extra ££ and got the Shadow version on the M771. It really does push the mech down and inwards quite a lot, leaving it much less exposed.
Sign In or Register to comment.