SLX Rear Mech Indexing frustrations

echowitch
echowitch Posts: 196
edited June 2012 in MTB workshop & tech
I have just recently fitted a new 9 speed cassette, chain, and SLX rear mech to my MTB (One month ago. The Crank has been on for about 6-12 months). However I'm having immense problems with getting the gears indexed. There's only the one barrel adjuster on the shifters and not on on the mech itself I've noticed. When the gears are indexed they don't seem to stay that way for long. The most they've stayed that way is 3 days. I cycle 15 miles a day Monday to Friday. #

Its really starting to frustrate me as my local bike shop normally indexes it for me and its got them stumped as well. When I try to do it makes things worse. Even making a small adjustment then putting it back does it, and now they seem to frequently crunch or skip. I never had this many problems with my previous Deore mech.

Can anyone suggest any fixes ? Anyone know the cause ?

The last thing to be done the other day was part of the cable was replaced. (Section at the rear of the top tube was replaced. All the rest of it is also about a month old.)

Comments

  • nicklouse
    nicklouse Posts: 50,675
    mech hanger bent?

    the fact there is only one adjuster makes no difference. you donr need two.

    re read how to set it up on Parktools and start again.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • echowitch
    echowitch Posts: 196
    I'll suggest that too them tonight when I take it back in again. Hopefully it is that simple :D
  • The Rookie
    The Rookie Posts: 27,812
    Rear QR not tight? My mech hanger doesn't sit flush to the frame unless the QR is tight, loosen it a little and the indexing goes to pot long before I pick up any other symptoms.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • bikaholic
    bikaholic Posts: 350
    Also check for play in the rear hub and the bottom bracket.
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    Could be a few things, rear hub bearings, damaged or dirty cable, misrouted cable, cable ends not seated properly, Cable too short, Damaged mech hanger, cracked frame, damaged or mismatched shifter.
    My photos
  • cooldad
    cooldad Posts: 32,599
    When I'm struggling, I replace the cables and start again after a deep breath, a cup of coffee and a cigarette (although I no longer smoke real ones). Works miracles.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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    Parktools
  • echowitch
    echowitch Posts: 196
    Problem solved......my bike hates Reading :)

    Or more specifically it hates the nasty gritty stuff all over the roads which keeps getting in to my chain and causing it to stick. The chain has been thoroughly cleaned and relubed with a thicker wet lube that will hopefully keep the majority of the gunk out but its still going to need redoing on a regular basis whilst this horrible weather continues. :?
  • echowitch
    echowitch Posts: 196
    Correction. I am still getting skipping. Or more accurately in about gear 5-8 I can't go up or down gear at a time, it won't shift over until I go up another gear. Its got my LBS stumped as well. They've suggested getting a cheap Deore rear mech off of Ebay (as they have none spare) and they will fit it for free. So far they've checked everything. The cassette and chain and mech are about 2 months old, and they've confirmed that its definitely NOT the chain or cassette. Crank is fine and is a year old. Shifters are a year old and confirmed as ok. (They swapped them over and still have the same issue.) And the cables have been partially replaced, and were again checked last night.

    One of the guys who checked the bike over said its like when mixing SRAM and Shimano parts and shifters. But its all Shimano parts.

    Any idea's ??
  • nicklouse
    nicklouse Posts: 50,675
    bent mech hanger. Or mech.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • echowitch
    echowitch Posts: 196
    Mech hanger is fine, and they've checked the mech and they've said thats fine as well. They think it may be the mech but they can't see anything wrong with it. Thats why Im trying to get a cheap Deore rear mech off of Ebay to test with. :p
  • echowitch
    echowitch Posts: 196
    A more mechanically minded colleague at work is going to take a look at lunch time. He suggested it might be the mech spring. If all else fails I may go sweet talk the local Evan's mechanics to take a quick peek at it.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    edited May 2012
    Doesn't sound like a great first LBS. They are not dealing with a rocket. Hope you get it sorted, but don't think getting another cheap mech is the best idea, best idea would be to borrow someone's that you know which works if you want to rule it out.
  • echowitch
    echowitch Posts: 196
    Well the mate at work has just said he has a spare but it needs cleaning first :) Which if I know him means its probably encased in mud :D
  • mister p
    mister p Posts: 405
    edited May 2012
    I reckon you have a 10 speed rear mech on a 9 speed system. What is the model number of the rear mech you are using? It will be on the back somewhere and should be RD-M6 something.
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    Chunkers1980 wrote:
    Doesn't sound like a great first LBS. They are not dealing with a rocket. Hope you get it sorted, but don't think getting another cheap mech is the best idea, best idea would be to borrow someone's that you know which works if you want to rule it out.
    I am blown away by the notion of a bike shop that doesn't have any Shimano rear mechs around somehwere to try out, if just to rule out a faulty mech.
    My photos
  • echowitch
    echowitch Posts: 196
    Yeehaa I think I took their last one, and they've had no cause to order new stock in. They mostly deal with BMX's and hybrid bikes.

    Mister P I will go and check the model number and post up later on :)
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    Even hybrids have mechs. I truly am surprised that they don't have any in.
    My photos
  • echowitch
    echowitch Posts: 196
    Lack of need I think. /shrug

    Okey dokes I checked (involved plenty of crawling around on the floor lol) and it says RD-M662 and underneath it looks like it says VIA.

    From what Im finding online it would seem to be a 9 speed.
  • mister p
    mister p Posts: 405
    That is 9 speed so should work with no issues. Fit some decent quality cables (Shimano SP41 outer and a decent quality Shimano inner). When I mechanic at events it is amazing how much better people's bikes shift from simply replacing their cables. Replacing just the inner doesn't make much difference but putting brand new outer on works a charm.
  • echowitch
    echowitch Posts: 196
    Cheers, I'll go measure the amount I need and order some :)
  • echowitch
    echowitch Posts: 196
    Finally my bike is fixed. The spring on the rear mech was defective it seems. The mechanic again suggested I get a cheap mech from Ebay to swap it to test. I pointed out that he had a 9 speed SLX rear mech in the window. I had to fight not to laugh when his face dropped as he realised he'd have to fit the new mech to replace the dodgy one they'd fitted two months ago lol

    To be fair it was also 5 minutes before they were to close. They also replaced the cable outers for free. :)

    I did however ride my bike like I stole it when I left lol

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