New rear mech not shifting - damaged shifter?

Discussion in 'Bicycle Mechanics and Repairs' started by beatleandrew, 15 Apr 2010.

  1. beatleandrew

    beatleandrew New Member

    I think I'll probably need to visit the local bike shop for this one, but thought I'd seek some advice here first from any experienced maintenance gurus who happent o be reading.

    I ride a 2008 model Specialized Roubaix, with Shimano 105 shifters & mechs and FSA chainset. I recently bought Planet-X Model B wheels. Riding back to London from Brighton after the March FNRttC, one of the rear non-drive side spokes snapped, fell into the chain and got dragged around the cassette and into the rear mech where it bent the arm holding the tension pulley out of shape. The wheel stopped turning, I couldn't move the cranks and the ride was prematurely over.

    I've just had the wheel back from Planet-X who repaired it without charge. I also bought a new Ultegra 6700 rear mech to replace the broken 105 - this should be compatible with my 105 shifter as they are both Shimano and both 10 speed (Shimano parts are interchangable).

    I attached the new mech and adjusted the right-limit screw to line up with the smallest cog. I connected the cable and tried shifting to the largest cog to adjust the left-limit screw. However, three clicks on the shifter didn't seem to pull the cable and the derailleur didn't move. I felt some pull on the cable after the fourth click and on the fifth I got a little derailleur movement but by the time I'd clicked as far as I could I was only half way up the cassette. So my first question is:

    Does the fact that I'm getting no pull on the cable for the first few clicks indicate that the shifter is damaged?
    My inital thoughts were tha the cable was not tight enough to begin with, so I reattached it a bit tighter and tried again, but no luck. I kept trying, experimenting with B-screw adjustments and cable tension. Eventually the cable snapped at the shifter end which ended my work for the evening.

    Anyway, now that the cable has snapped, the shifter will only move three clicks in either direction. So my second question is:

    Should a dual brake/shift lever click right through ten times in either direction when not pulling against anything, or should there be no clicks at all?
    Any tips would be most welcome. I haven't much experience with derailleur installation, but I'm pretty sure I've followed the instructions correctly. The bike will probably end up in the shop now, but I'd love to hear from anyone who might understand what my problem is.
     
  2. GilesM

    GilesM Guru

    Location:
    East Lothian
    I would recommend feeding a new gear cable into the shifter and through to the rear mech, do not connect the cable to the rear mech, just hold it tight in one hand, and with the other hand operate the shifter, you should be able to feel the ten shifts up and down, if not then have a closer look at the shifter. Also make sure the end of the gear cable is correctly seated within the shifter.
     
  3. OP
    OP
    beatleandrew

    beatleandrew New Member

    Cheers Giles. I'll try to pick up a cable on my way home tonight and give it a try.
     
  4. OP
    OP
    beatleandrew

    beatleandrew New Member

    Right. It looks like what happened is that the ball on the end of the gear cable had fallen out of position inside the shifter while the cable wasn't attached to anything at the derailleur end. As it was out of place, the ratchet in the shifter wasn't picking it up and pulling it for the first few shifts. The ball being stick in an awkward position also would have contributed to the cable snapping after several attempts to get the shifting to work properly.

    I've given the cable housings a little clean out with some oil and will try to piece everything back together with the new cable this weekend and see if I can get the new derailleur working properly.

    Thanks for the tip, Giles! :wacko:
     
  5. arallsopp

    arallsopp Post of The Year 2009 winner

    Location:
    Bromley, Kent
    Sorry to hear of your ongoing woes mate.

    My derailleurs have given me a fair amount of pain in the past, causing me to adopt this technique when fitting / debugging / adjusting:

    • Undo the cable completely.
    • Move the derailleur between limits manually with your hand. (guiding or removing the chain as need be)
    • Dial in the limits by eye.

    With that set right, almost everything else will be cable tension.

    YMMV, but its worked for me a number of times. Too many unknowns on a 'bent (and a long walk from wheel to pedals) to assess multiple parameters at once :smile:
     
  6. OP
    OP
    beatleandrew

    beatleandrew New Member

    Yeah, I'm starting to get a little frustrated after almost three weeks off the bike, so hopefully I'll have it all repaired this weekend. Having a broken bike while there's been such nice weather outside is really sad. Fortunately, I have managed to put some faster, slicker tyres on the Brompton, so I've at least been able to get a bit of speed up on my commutes.

    I can push the derailleur right across the cassette manually, so that seems to be ok. I'll follow your steps and hopefully that will do it!
     
  7. actonblue

    actonblue Über Member

    Have you also checked that the gear hanger is still straight? It could have been bent by the spokes and that would also effect your shifting.
     
  8. OP
    OP
    beatleandrew

    beatleandrew New Member

    Yes, I had a check and the gear hanger looks straight.

    I'll have another go at getting the derailleur working during the weekend and report back on Monday!
     
  9. e-rider

    e-rider crappy member

    Location:
    South West
    this should be straight forward - from reading the first post only, it sounds like a cable routing issue. Have you doubled checked that the cable is in all the right places? and you're not using brake cable outer cable are you?!!!

    Snapped cable!!! how hard are you pulling it? These shifters are not bomb proof.
    Although I'm all for DIY when it comes to bikes, in this case I think you might damage your shifters (which will be expensive) if you carry on so perhaps go to LBS.
     
  10. gwhite

    gwhite Über Member

    Location:
    Auchtermuchty Fife
    By the way, a ten speed shifter should only have 9 clicks given that your starting place is position 1. Good luck.
     
  11. Good luck Andrew - don't forget to make sure the rear end of the cable connecting the mech is located in the groove of the clamp...:smile:

    I have Shimano and I'm dreading anything going up the spout - all my others are Campagnolo gist...'the bells, the bells!'
     
  12. OP
    OP
    beatleandrew

    beatleandrew New Member

    Thanks so much for all of the advice and encouragement!

    I started over on Saturday with the new gear cable. However, I could only get the derailleur to span 8.5 of 10 cogs.

    Going back to arallsopp's advice, I took the chain right off and disconnected the cable. The right limit was dialled in nicely, but manually pushing the unconnected derailleur across the cassette, still only spanned 8.5 cogs (sorry for my earlier comment to the contrary, I thought I'd been able to push it right across but obviously hadn't given sufficient attention to it).

    I compared it to my old mangled 105 and sure enought the 105 can push across the full ten gears but the new Ultegra can't, even though it is supposed to be ten speed.

    I'm thinking now that the new derailleur is faulty and needs to be returned, unless I'm missing anything. Can anybody think of anything else to try before I send the derailleur back to the shop?
     
  13. arallsopp

    arallsopp Post of The Year 2009 winner

    Location:
    Bromley, Kent
    Ok. I may be teaching granny's to suck eggs, but here's how I'd play it:

    If the jockey pulley clears the sprockets, and the 1.5 gears missing are those with the biggest number of teeth, loosen the low gear limit stop (probably labelled 'L').

    If the jockey pulley is fouling the sprocket, and the 1.5 gears missing are those with the biggest number of teeth, tighten the angle adjuster (possibly labelled 'B').

    If the 1.5 gears missing are those with the smaller number of teeth, loosen the high gear limit stop (probably labelled 'H').

    If none of the above looks to be the culprit, or any of the limits can't be dialled out far enough to give the full range, I'd be wondering whether the old 105 bent the rear drop out in its death throes.
     
  14. OP
    OP
    beatleandrew

    beatleandrew New Member

    Got it working. Schoolboy error I'm afraid, so Andy, thanks for sparing me from any further embarrassment.

    What I'd failed to note (and observe) is that tightening the L screw moves the pulley to the right where as tightening the H screw moves it to the left. Both, of course, have a similar role: tightening pulls the limit inwards and loosening outwards. I'd just had it in mind that tightening moved the limits to the left and loosening to the right regardless of which screw it was. I'd had the L screw fully tightened, expecting it to be wide of the large cog and need pulling in, but of course the opposite was true which explains why I the derailleur could only span 8.5 cogs. Seems obvious now! :angry:

    You'll see that this is clearly my first time engaging in any serious tinkering with cables and derailleurs, but hopefully this experience will aid my slow progress from Know How advisee to advisor. Rather than take my bike into the shop every time something goes wrong, I'm determined to learn how to fix bike problems myself as they arise. This case has really helped me along with that, so many thanks to everyone who's helped me out!

    Looking forward to seeing some of you on the next FNRttC! :sad:
     
  15. e-rider

    e-rider crappy member

    Location:
    South West
    Yes schoolboy error - but that's how we all learn. Glad you got it sorted in the end. In my experience Shimano products are very rarely faulty straight out the box; after all they are Japanese.
     
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