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Shimano rear mech? cassette? problem

AndyRubioAndyRubio Posts: 880
edited April 2017 in Workshop
Hi,

I recently (yesterday) put on a new cassette and chain onto my Shimano 10-speed gearset. The problem I have is that, when in the middle gear, the chain and the rear mech start doing a 'clicky-clicky' thing. It's pretty much ok in the other gears.

'Clicky-clicky' thing seems to invove the chain not being properly in line with the rear mech. Twice per rotation of the crank.

Possible culprits:

* The new cassette is 11-28, previously 12-27. I erroneously kept the new chain to the same length, should be 2 links bigger - but I don't see how that could affect things.
* I might have switched round the pulleys of the rear mech, but I've tried both configurations. The pulleys appear to be identical, although one has an arrow of rotation, the other one doesn't. I've read that one is a 'guide' and one is a 'tenson' pulley.
* Brand new wheels (thank you Paul Hewitt!). I don't see how this would affect things.

I've got a 12-27 cassette on order to see if that fixes it.

If you have any ideas on how to address this problem, I'd be eternally grateful!!

Thanks,
Andy

Posts

  • MatthewfalleMatthewfalle Posts: 17,380
    Did you adjust the indexing at all?
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • AndyRubioAndyRubio Posts: 880
    Did you adjust the indexing at all?
    Is that the twisting device that attaches the cable? if so, yes - but it didn't help. The clicky-clicky moved to different gears.
  • MatthewfalleMatthewfalle Posts: 17,380
    If it's moving to different gears that may suggest an indexing problem - I think that if it was the old chain not meshing with the new cassette then the clickety click would remain constant.

    Are you ok at a complete re-index or do you need a bluffer' guide? It's not difficult at all - remarkably simple in fact.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • AndyRubioAndyRubio Posts: 880
    I've never done it before so any help would be madly appreciated thanks!
  • arlowoodarlowood Posts: 2,538
    AndyRubio wrote:
    I've never done it before so any help would be madly appreciated thanks!


    One of the better Youtube videos on correct indexing of you gears

    https://www.youtube.com/watch?v=SkzvfCaIbyQ
  • svettysvetty Posts: 1,904
    Not sure why you've dismantled the jockey wheels but as long as you have put the cage back together properly this shouldn't be an issue. The change from 27-28 won't make a difference - you don't need a longer chain to accommodate this unless you were at the absolute limit before on chain length which is unlikely. New wheels may be a factor - I assume you fitted have the required spacers behind the cassette?

    Basically it sounds as if you just need to make sure you've put everything together correctly then adjust the indexing properly.
    FFS! Harden up and grow a pair :D
  • MatthewfalleMatthewfalle Posts: 17,380
    I found the videos really confusing then I spent some time with a friend in his shop and he showed me at it's as simple as.

    1. Put bike in smallest rear cog, smallest front.
    2. Release cable completely.
    3. Use flat blade screwdriver. You have two screws on the rear mech. When you turn one of these you'll see the mech left and right(in and out).
    4. Sit/stand/squat/whatever behind the bike and using the screwdriver and the screw line up the mech so that the middle of the chain is perfectly in line with the middle of the cog.
    4. This is the trickiest part. Now, push the mech in towards the biggest sprocket while turning the cranks. Hold it in place over the biggest sprocket or get someone to do it for you.
    5. Now using the same screw, adjust the mech so that the middle of the chain is in the middle of the sprocket.
    6. Turn pedals so that the chain goes back to the bottom cog.
    7. Turn the barrel adjuster (big black knobble bolt screw thing that the cable goes into) all the way in then turn it out 2 full turns.
    8. Pull cable finger tight (no need for pliers) and do up bolt that holds it in. No need for FT here, just nipped up nicely.
    9. Turn pedals and change gear to go to the biggest sprocket. If it doesn't slip in, turn the barrel adjuster I. The direction that you want the chai to go. This tensions and releases the cable.
    10. Do that until it changes through the cassette.
    11. Once you have that then shift through the gears a few times making sure it works.
    12. Then go through the gears really slowly turning the barrel adjuster really slowly (generally a 1/4 of a turn at a time) until it's as slick as me on the dance floor.
    13. Job jobbed. Retire to the front room, pop on NATN, drink beer.

    The most important part is getting the mech sitting central to the big and small cogs.

    Hope that sounds ok - it really is as simple as anything.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • AndyRubioAndyRubio Posts: 880
    Thanks folks!

    It's all (almost) beautiful now, good ride out today, felt gooooooooood.

    Still something not quite right though, but am going to wave the white flag and take it in to Hewitt's. They'll sort it in 20 seconds.

    Cassette's on correctly, spacers all good. I replaced the pulleys, looks like I had 2 guide pulleys! I'd removed them for cleaning BTW.

    I really appreciate your posts, and I learned about indexing so thanks for that.

    Andy :)
  • izzaizza Posts: 1,561
    Mech hanger not true?
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