Drivetrain Pissing Me Off

nakita222
nakita222 Posts: 341
edited December 2011 in Workshop
Yesterday my chain started skipping about on the rear cogs, more frequently on the bigger ones than the smaller ones. When I got home I adjusted the rear cable tension, so that the shifting was perfect. I went for a ride today and my chain started jumping about again, even though it was fine on the work-stand, and when I was in the bigger sprockets out back, the chain would jump off the big ring, or occasionally slip down onto the small ring. When i got home today, I adjusted the rear derailleur cable tension, so it was perfect, check the chain rings for bent teeth. Checked the bottom bracket for play, checked the derailleur hanger was straight and checked the chain had no bent or stiff links. Does anyone have any other suggestions as to why my bike would be doing this.

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    Classic signs of a worn chain
    Make mine an Italian, with Campagnolo on the side..
  • The chain has only done around 1,500 miles, and gets cleaned regularly.
    Also worn chains usually go more gradually, and start off with small problems, and lead to huge problems,mine went from being perfect, to absolutely shite in the space of a week

    Is that the only solution?
  • desweller
    desweller Posts: 5,175
    Freehub failure / lack of grease? You haven't been cleaning it with solvents have you?
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  • crankycrank
    crankycrank Posts: 1,830
    Is your shifter cable moving freely? May need a good cleaning and lube. Make sure the shifter cable is not starting to fray and don't forget to check the cable end that goes into the shift lever as well. Also make sure the cable fixing bolt on the rear mech is tight.
  • the freehub is fine because when i back pedal, there is no resistance, and the wheels are new. It could be the cables.
    I was also wondering whether the wheel not being seated properly in the dropouts could cause this, As I am using exposed cam quick release skewers, which are notoriously bad, and could be causing the wheel to slide down a bit. I'm not sure though.
  • fludey
    fludey Posts: 384
    Had a similar problem on a mounting bike and turned out to be a sticking cable but was worse on down shifts. Worth a look perhaps?
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  • Diogenes
    Diogenes Posts: 1,628
    fludey wrote:
    Had a similar problem on a mounting bike and turned out to be a sticking cable but was worse on down shifts. Worth a look perhaps?

    +1. Try stripping the inner out and give it a good looking over and clean up, possible there is a piece of crap in sleeve. I would even be inclined to replace the cables.

    D :D
  • keef66
    keef66 Posts: 13,123
    +2 My recent shifting problems turned out to be a cable on the point of disintegrating inside the shifter.

    Of course by then I'd removed, cleaned and lubed the chain, the rear mech and the cable outers; that was the last thing I looked at!

    New cable and now it's all slick shifting and very clean and shiny!
  • Thanks guys, but two questions. How would you clean a cable outer, without an air compressor, and also my chain is jumping and slipping randomly off the at the front as well as the rear, not just when i'm shifting, just making sure this could be down to a sticky cable.

    Thanks for the help.
  • desweller
    desweller Posts: 5,175
    Stiff or twisted link? Can happen if the chain gets tangled up, no matter how new it is.
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  • keef66
    keef66 Posts: 13,123
    I hold the outer vertically and trickle oil in at one end until it starts coming out of the other, then insert a length of old (but clean and rust free) cable to give it a bit of a flossing. Pretty tedious getting the oil in cos the holes are so small.

    Not sure your random chain events at the front could be down to a gunky cable though... You sure the chain's not knackered in some way??
  • glasgowbhoy
    glasgowbhoy Posts: 1,341
    Been watching this thread as I seem to have the same issues.

    Run Tiagra on my winter trainer. Recently changed the chain, cassette and the chainrings but noticed the chain was slipping quite regularly especially when climbing. Took it to my LBS and they changed the cable. The problem is still there and not sure how to sort it. Cant see any damage to the chain and the cassette is a new Tiagra block.

    Very frustrating
  • crankycrank
    crankycrank Posts: 1,830
    nakita222 wrote:
    the freehub is fine because when i back pedal, there is no resistance, and the wheels are new. It could be the cables.
    I was also wondering whether the wheel not being seated properly in the dropouts could cause this, As I am using exposed cam quick release skewers, which are notoriously bad, and could be causing the wheel to slide down a bit. I'm not sure though.
    The freehub pawls may still not be grabbing properly even though it backpedals fine. A good flush and relube may be worth a try but you may have to disassemble it for inspection. Check to see if the freehub is on tight as well as the lockring for the cassette. Skewers are a possibility especially if you have vertical dropouts as the axle can slip and then can be forced back into position from your weight and appear to be fine when you stop to inspect. Horizontal dropouts the axle will most likely remain skewed until you loosen the skewers. If you have a spare set of reliable skewers do a switch to see if it helps. Have you checked to make sure the axle isn't bent or broken? Also check the mechs including the rear pulley's and cage rotation with the chain off to make sure everything moves freely and the springs are working properly.
  • Diogenes
    Diogenes Posts: 1,628
    nakita222 wrote:
    Thanks guys, but two questions. How would you clean a cable outer, without an air compressor, and also my chain is jumping and slipping randomly off the at the front as well as the rear, not just when i'm shifting, just making sure this could be down to a sticky cable.

    Thanks for the help.

    Pull the inner out (that often brings crap with it), spray some WD40 inside (its messy) which should free up any other debris and then "floss" with a piece of clean cable.

    If the cable is sticking then it can slowly come free as you ride along and you lose the tension imparted when changing gear.

    You may have to replace the outers as well if they are badly corroded.

    I am surpised that you are suffering front and back mech issues, what are the chances of both sets of cables being duff? Checking / changing is a straightforward and relatively cheap test so worth doing.

    Good luck.

    D :D