Chain "jumping" on rear cassette

lukeatlarge0
lukeatlarge0 Posts: 12
edited March 2008 in MTB workshop & tech
Hi all. Before I start I should explain I'm fairly new to mountain biking so may seem a bit thick. I have an XT 9 speed cassette and a HG 93 chain, both less than 100 miles (and two months) old. I use my bike for fairly aggresive XC. Recently when powering uphill the chain jumps on the rear cassette, it seems to be being thrown off the second and third sprockets (from the top of them not the bottom where the derailluer is (XT Shadow long cage)) and "mashing" its way on to the fourth or fifth sprockets; this causes the pedals to spin for about quarter of a turn breifly engage the higher gear then change back to the lower gear again when it may or may not start the whole process again. I find it hard to believe the chain or cassette could have worn out so quickly.
Anyone got any idea what could be causing this and how I fix it.

Comments

  • robbiemagic
    robbiemagic Posts: 132
    I had a similar problem with mine and it was just the casette that needed tightening up and then it was fine!
    "Second place is the first loser"
    Orange Five SE
    Orange P7 one
  • nicklouse
    nicklouse Posts: 50,673
    check the cable tension and that there are no stiff links. How toos on parktools.linky below.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Crayfish
    Crayfish Posts: 225
    Same problem on my new Stumpy after 40 miles with an SRAM chain. It was a stiff link. Put bike in stand and turn pedals slowly and you will see it jumping on one particular link - the same one every time.

    My solution was to stick a pair of long nose pliers in the link to widen it a bit, then lots of lube and playing with it by hand. The link will free up after a while. You will always need pleanty of lube on it though.

    Good luck.
    http://www.youtube.com/user/stumpy25lbs
    Choose a ****ing big television. Choose washing machines, cars, compact disc players, and electrical tin can openers. Choose a bike. Choose some singletrack. Choose your future. Choose Life. (Irv Welsh)
  • artillerydave
    artillerydave Posts: 715
    sounds like your indexing is out a touch, a quick l=play with the barrel adjuster on your shifter should sort it out, cables do strech a bit after initial use so this is to be expected not worn out, hence the reason most good bike shops do 6-8 week checks.
  • lukeatlarge0
    lukeatlarge0 Posts: 12
    Thanks everyone, feel a bit stupid now. Cable had streched, couple of clicks on the barrel adjuster and it works like new. There you go another thing learnt.
  • cl1988
    cl1988 Posts: 19
    had the same problem with my hardrock didnt really do anything and it stopped doing it is it common for shimano cassettes or just something that happens

Categories