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Chain fannying around on rear cassette

CorianderCoriander Posts: 1,326
edited September 2008 in The workshop
Hi,

More technical help, please.

I went out for a long ride today and suddenly my rear cassette (that is the group of gear rings at the back, isn't it?) started behaving very strangely - sometimes it wouldn't respond immediatley when I tried to change gear, sometimes it would jump all over the place with corresponding amounts of clunking noise even though I wasn't touching the gear levers, and other stuff that wasn't much use to me when riding. It did this for the remaining two hours of the ride.

What's wrong - any ideas?

I was just about to say that I cleaned and lubed the chain a couple of weeks ago as proof that I look after it, but knowing me, that's probably the cause of the problem. :oops:

Posts

  • Its unfixable. You need a new bike I'm afraid.
  • nicklousenicklouse Posts: 81,520 Lives Here
    have you had an off?

    if yes you may have bent the rear mech hanger.

    if no i would say that either the gear cable in mucky and needs a clean and lube (internally) or you need to add a touch of tension to the cable as it could well have stretched a bit.
    there will be an adjuster on the gear shifter, have a look at the indexing gears on the park tools webby, but i would start with a click counter clockwise when looking from the cable end at the shifter.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • cjcpcjcp Posts: 13,345
    nicklouse wrote:
    have you had an off?

    if yes you may have bent the rear mech hanger.

    if no i would say that either the gear cable in mucky and needs a clean and lube (internally) or you need to add a touch of tension to the cable as it could well have stretched a bit.
    there will be an adjuster on the gear shifter, have a look at the indexing gears on the park tools webby, but i would start with a click counter clockwise when looking from the cable end at the shifter.

    Seconded.

    Cori - when was the last time the gears had a tune?
    FCN 2-4.

    "What happens when the hammer goes down, kids?"
    "It stays down, Daddy."
    "Exactly."
  • CorianderCoriander Posts: 1,326
    nicklouse wrote:
    have you had an off?

    if yes you may have bent the rear mech hanger.

    if no i would say that either the gear cable in mucky and needs a clean and lube (internally) or you need to add a touch of tension to the cable as it could well have stretched a bit.
    there will be an adjuster on the gear shifter, have a look at the indexing gears on the park tools webby, but i would start with a click counter clockwise when looking from the cable end at the shifter.

    Nick and Cj, thanks, you're genii. I turned the button thing on the gear cable and bingo, no more fartarsing around!! You're stars, thanks

    Cori
  • nicklousenicklouse Posts: 81,520 Lives Here
    well you did describe the problem so well.

    :wink:
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • biondinobiondino Posts: 5,990
    So I developed a problem along these lines with the Focus today, just as I was heading out on a very hilly ride in The Weald in Sussex. After 20 mins I managed to find the right combination of cable tension and Low limit screw turnage to sort the problem. Yay, I R bike mechanic!

    Except I guess I'm not. On the last 10 yards of the last hill of the day, I am up in the pedals and straining hard and suddenly something seizes and I'm thrown forward and left and collapse onto the verge. Couple of bruises from the handlebars hitting my legs (you can tell exactly what relative leg position I was riding in at the time by the placing of the bruises!), but no damage to either me or bike. So I think "what the hell happened?", expecting to see a chain off or similar. Nope - the back wheel had come out of the dropouts :shock:

    Now I had noticed a couple of times previously my quick release levers had worked themselves loose (with no ill effects, just a quizical look and an assumption that I'd knocked them while off the bike), but I was happy with the tightness of each and had even checked the rear one before this ride. Does this happen to anyone else?

    Anyway, my questions:

    1. Is it likely I damaged any part of the bike? The rear wheel, I noticed, is further out of true again but that may just be the spoke from last time working itself loose. No other obvious issues but obviously I don't want to ride a bike with damaged parts. I've now done over 1,000 miles on it so perhaps a 1st service is overdue anyway?

    2. Is there a correct tension to tighten a quick release skewer and any rule of thumb for doing so?
  • nicklousenicklouse Posts: 81,520 Lives Here
    get it serviced should be ok.

    2: yes there are, first which side do you have the lever on? I favour the non mech side. Now when the lever is lifted over and pressed home you must make sure the lever does not touch anything as it must be able to go "over center" on the cam.

    now the force needed to move the lever over should leave a nice impression on your Palm/thumb.

    it is also nice to have the lever pointing to the rear.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • cjcpcjcp Posts: 13,345
    nicklouse wrote:
    well you did describe the problem so well.

    :wink:

    And he deserves a pat on the back for setting this techy section up too. :)
    FCN 2-4.

    "What happens when the hammer goes down, kids?"
    "It stays down, Daddy."
    "Exactly."
  • cjcpcjcp Posts: 13,345
    nicklouse wrote:
    it is also nice to have the lever pointing to the rear.

    This is interesting. Is this to reduce the risk of it catching anything as you're riding? I've always had mine so that it rests just underneath the non-drive chainstay because it looks "neater". :roll:
    FCN 2-4.

    "What happens when the hammer goes down, kids?"
    "It stays down, Daddy."
    "Exactly."
  • nicklousenicklouse Posts: 81,520 Lives Here
    cjcp
    i do the same as you :oops:
    but yes the idea is so that if it get caught by something it is not possible to flip it open.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • cjcp wrote:
    nicklouse wrote:
    it is also nice to have the lever pointing to the rear.

    This is interesting. Is this to reduce the risk of it catching anything as you're riding? I've always had mine so that it rests just underneath the non-drive chainstay because it looks "neater". :roll:

    more Aero innit! And it looks better. :D
    2015 Canyon Aeroad CF SLX
    2020 Canyon Ultimate CF SLX
    2020 Canyon Inflite SL 7
    On the Strand
    Crown Stables
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