Twisted chain

lonzo
lonzo Posts: 62
edited March 2011 in MTB workshop & tech
:cry:
My last two chains a KMC X9 73 and a SRAM PC951 have developed twisted links causing really annoying phantom shifting. I have a truvativ blaze chainset (22, 32, 44), deore front mech, a shimano LX cassette and an SLX rear mech.

Have previously run PC951 chains with no problems until changing to KMC chain and SLX rear mech (previously a LX mech)

Is there a problem with my set up or am I just too big(14.5 stone)?

are some chains tougher than others?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    how do you use your gears?

    have a read.

    http://www.bikeradar.com/forum/viewtopic.php?t=12647117
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • lonzo
    lonzo Posts: 62
    edited March 2011
    Thanks for the reply. I don't think this is the problem - I don't use the high gears in the granny ring or low gears on the big ring and the twist tends to be in one or two links rather "the chain" as a whole. I would post a photo but I think it would be too difficult to see properly what's going on.

    I certainly have the odd gear change that is less than smooth - could that be the problem?
  • nicklouse
    nicklouse Posts: 50,675
    must be something you are doing.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • lonzo
    lonzo Posts: 62
    So I can rule out any problems with the set up?

    I know the chain doesn't twist itself, so what type of thing that I might be doing could twist a chain?

    I quite often stick the bike in the boot of my car - could the chain be twisted by the weight of the bike? seems unlikely when I think about the amount of force required to straighten the chain back to make it run smoothly?
  • nicklouse
    nicklouse Posts: 50,675
    parts are fine though I wonder why you went from LX to sLX they are basically the same.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • lonzo
    lonzo Posts: 62
    the LX was the stock one fitted to the bike from new (2005) it had taken a few hits over the years, it needed a second replacement jockey wheel and I felt it was a bit slack so I bought a SLX when they were on offer. I have found that the tension is better (and adjustable) - seems to reduce the number of times the the chain gets dropped when it gets rough
  • konadawg
    konadawg Posts: 447
    I have had chain twists with Shimano too so it's not a chain-make issue. I'm almost 100% convinced that a single bad shift under load does it, or something similarly violent.

    I would use two pairs of pliers to twist the chain straight again, usually the damage is on one or two links. Yes you must do this, a twisted chain does not make for smooth shifting and will likely result in a broken one in short order.

    Aside, I went to KMC from Shimano, but was greatly disappointed. I had a link plate tear in the middle (taking out my derailleur hanger with it) and thought it was an exceptional occurrence, but less than a month later another link plate also tore, this time around the pin, and that was the final straw - I had never, ever had this happen with any Shimano chain.

    The first incident the chain was barely 3 months old.
    Giant Reign X1
  • lonzo
    lonzo Posts: 62
    Cheers dawg, comforting to know I am not the only one with this problem - already resorted to pliers but thanks for the tip, again comforting to know someone else doing the same!!

    Also I found the bottom of the range KMC chain to be generally poor compared to the bottom of the range sram - I chucked it in the end and went back to sram but was surprised when the problem recurred.

    Sounds like it's something I may have to live with or learn to nurse the gears!
  • The Rookie
    The Rookie Posts: 27,812
    Shifting under high torque puts a twisting force on the cahin when its part wrapped on 2 gears, this is at its highest just before it lifts off the ring your changing from and worse when changing down a gear (and likley to be at higher torque if your just starting a climb for example), that's just physics, being a big guy I guess your backing off is relative!

    Simon
    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.
  • lonzo
    lonzo Posts: 62
    lol, yeah I need a fair bit of torque just to get going!

    From what yo're saying I think this comes down to technique rather than hardware - I need to do all my gear shifting before I get into a high torque situation.

    Cheers
  • cavegiant
    cavegiant Posts: 1,546
    This is caused almost all the time by chainsuck or bad shifting.

    The X9 chain is ridiculously strong, so not a small thing to bend it. However it is a small thing to bend it back. Two adjustable wrenches, clamp, and twist.
    Done that a few times (I normally treat my X9 chains poorly cause they can take it), and no issues.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?

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