Chain rubbing @ jockey wheels

scottc1978
scottc1978 Posts: 20
edited April 2014 in Workshop
Just had a new chain and cassette (Tiagra 12-28) fitted by a local repairer.

I've noticed now that when I'm running on the smallest 5 cogs at the back and the smallest ring on the front the chain is rubbing on the cage of the jockey wheel. Is this something to do with the tension on the rear cage? Perhaps the chain is too long?

Took it back to the repairer, he adjusted the B-screw, said that the chain is the correct length and it's just one of those things that you have to live with.

Have attached a photograph.

Comments

  • slowbike
    slowbike Posts: 8,498
    Find a different local repairer ...

    Things that cause chainrub

    B Screw not in far enough
    Chain too long
    mech too short for the range of gears on the bike

    28-12 is within the abilities of a short cage shimano mech.

    Look up how to size chain ... then just for us here - put the chain in the big ring at the front and the big cog at the back and then take another pic of the mech as you've done above... :)
  • peteone
    peteone Posts: 152
    Can you show us a zoomed out pic so you can see the chainline between the chainset and cassette. From the pic above it looks like the chain is too long.
    Cervelo R3
    Giant TCR SL
    Ibis Tranny
  • keef66
    keef66 Posts: 13,123
    +1 Try a better bike shop. That chain looks far too long to me.
  • darkhairedlord
    darkhairedlord Posts: 7,180
    Even if the RD is short it appears to be on the 15 in the photo so shouldn't be a problem.
    As above, photograph with it on Big-Big and post it up.
    No amount of twiddling the B tension screw is going to dial that out.
    Chain looks waaaay too long. Although a sticky pivot post can lead to similar problems (I don't think this is the case). Buy a chain splitter and sort it yourself, it's really not that hard and plenty of tutorials about.
    Then take the removed links an put them in the "repairers" sandwiches.
  • drlodge
    drlodge Posts: 4,826
    +1 on the chain looks too long.
    WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
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  • scottc1978
    scottc1978 Posts: 20
    Thanks guys.

    I'll post a few pics when i get home.
  • JayKosta
    JayKosta Posts: 635
    When using the Big / Big gear combination, having the rear deraileur doing only a minimum amount of chain 'take-up' should resolve the problem. Shorten the chain as needed.

    Jay Kosta
    Endwell NY USA
  • kwozzymodo
    kwozzymodo Posts: 45
    Looks like your chain is too long, by at least 8 links. My chain has 106 links and I run a 50 front chainring and a 12 smallest rear cog. The derailleur cage should be near enough vertical when in 50/12.

    My guess is someone has just taken a new chain out of the box and installed it without measuring the required length, which varies according to a bike's gearing.

    No sweat though - just remove the excess links and refit. At least it's not too short!
  • scottc1978
    scottc1978 Posts: 20
    Photo in big ring, big cog.
  • kwozzymodo
    kwozzymodo Posts: 45
    Big ring/biggest rear cog should leave the jockey cage pointing forwards at about 45 degrees. Looks like the answer is to remove those links.....
  • darkhairedlord
    darkhairedlord Posts: 7,180
    Yep, chain way too long. your "repair" man was too incompetent to do it correctly the first time and too lazy to put it right the second time. Take it back and tell him to sort it out. If he still won't put it right, Name and shame.
  • slowbike
    slowbike Posts: 8,498
    darkhairedlord wrote:
    Yep, chain way too long. your "repair" man was too incompetent to do it correctly the first time and too lazy to put it right the second time. Take it back and tell him to sort it out. If he still won't put it right, Name and shame.

    Nah - just get a chain tool and fix it yourself and find a new repair man - he's had 2 chances - don't give him the chance to balls it up again - it's not worth it.
  • scottc1978
    scottc1978 Posts: 20
    Fixed now thanks to my neighbour. Watching over him as he done it so might get one of those tools and tackle it myself in the future.

    Diagnosis: Sunrace chain with a KMC missing link. Had to remove around 8 links.
  • spanner239
    spanner239 Posts: 181
    scottc1978 wrote:
    Fixed now thanks to my neighbour. Watching over him as he done it so might get one of those tools and tackle it myself in the future.

    Diagnosis: Sunrace chain with a KMC missing link. Had to remove around 8 links.

    8 links! Looks like the person who installed it in the shop just put the brand new chain on without checking the appropriate length. Never, ever go there again, who knows what other shortcuts they will take with your bike!
  • crankycrank
    crankycrank Posts: 1,830
    +1^^^. That is what I would rank as inexcusable for a pro mechanic. The OP would be justified in asking for a partial refund of labour costs seeing not only did the mechanic do it wrong but he then claimed it was done properly requiring scottc1978 to take care of it himself. :evil: This place would be worthy of a name and shame if you don't get a refund IMO.

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