Chain Slipping.

andytxc
andytxc Posts: 666
edited February 2008 in MTB workshop & tech
Ok, when I put power down in the 7,8&9 gears, the chain, or something, constantly slips.

I have only one 32tooth chainring at the front.

I have checked the normal things;

Brand new chain at the correct length

Brand new cassette

Hub is good

Gears adjusted and hanger not bent.

Any solutions?

Thanks.

Comments

  • nicklouse
    nicklouse Posts: 50,673
    if it is as you say and there is nothing clogging up the cassette and the spds are correct then it needs looking at as something is not working as it should.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • andytxc
    andytxc Posts: 666
    hmm so i suppose its a take one thing off and replace it to see if it works kinda thing!

    Thanks for your reply.
  • nicklouse
    nicklouse Posts: 50,673
    no, get it looked at buy some one who knows.

    But first check for stiff links.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • andytxc
    andytxc Posts: 666
    ok, I work in a bike shop and nobody there knows! I may take it somewhere else. And it's not stiff links, I have checked.

    Cheers
  • nicklouse
    nicklouse Posts: 50,673
    list the parts then.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • andytxc
    andytxc Posts: 666
    Shimano deore rear mech

    SRAM P991 chain (i think)

    Shimano xt rear cassette.

    The same setup works on my stumpjumper (except I have an xtr rear mech)
  • nicklouse
    nicklouse Posts: 50,673
    check the chain, are the jockey wheels 8 or 9spd. 9 are a tad thinner.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • andytxc
    andytxc Posts: 666
    I'm not sure. I think they are 9speed jockey wheels.

    I'll have a butchers tomorrow.

    Thanks for your help.
  • nicklouse
    nicklouse Posts: 50,673
    i am grabbing at straws now. just check what every thing is and then with the bike in the stand see where it is happening.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Drfabulous0
    Drfabulous0 Posts: 1,539
    Well it's unlikely to show up in the stand, put the bike in a turbo trainer and have somebody pedal it hard while you sit on the floor and watch the drivetrain to see where it's skipping.

    Did you get the chain from the box at the back of the workshop? Is it actually a 9 speed?

    Are your jockey wheels knackered or the mech bent?

    Did you use a powerlink, is it the right one? If you didn't check the pin on the link you joined isn't sticking out too far and catching on the cassette.

    Is the chainline right?

    Is the chainring worn?
    <center><font><b>My Scott</b></font></center>
    <center><font><b>My Kinesis</b></font></center>
  • RideTheLakes
    RideTheLakes Posts: 209
    You have either a worn cassette or a worn chainring that needs replacing, possibly both. It often only becomes apparent when you buy a new chain.

    Incredible that your lbs couldn't work that out! Find a new shop :D
    Lake District Mountain Biking
  • nicklouse
    nicklouse Posts: 50,673
    Drfabulous0
    it is amazing what can be seen on the stand that is not always visible on the trainer or road.. but yes a good load on the drive train can help.

    RideTheLakes
    he does have a new cassette.

    but it could be lifting on the chain ring, but it would have to be very worn.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • RideTheLakes
    RideTheLakes Posts: 209
    nicklouse wrote:
    Drfabulous0
    it is amazing what can be seen on the stand that is not always visible on the trainer or road.. but yes a good load on the drive train can help.

    RideTheLakes
    he does have a new cassette.

    but it could be lifting on the chain ring, but it would have to be very worn.

    Ah yes not the cassette so definitely the chainring.
    Lake District Mountain Biking
  • andytxc
    andytxc Posts: 666
    Chain ring brand new on both cranks I've tried. Thats why I just can't work it out! Oh, and the chain is a PC971 (still compatible). And it doesn't show up in the stand!

    I have actually never been so puzzled!

    I have lots to try now, thanks for the ideas :)
  • ride_whenever
    ride_whenever Posts: 13,279
    Chain tight enough?

    What is the chainline like, from the sounds of things, gears 789, might be an alignment thing, have you go a chain device?
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • andytxc
    andytxc Posts: 666
    I have a chain guide at the front and the chain cant really be tightened anymore. I may get a roadie cassette and tighten my chain.
  • ride_whenever
    ride_whenever Posts: 13,279
    Everything is new then, are you sure the mech is set up correctly, could it be cable stretch meaning the gears are not indexed and so jump around under power?
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • robbarker
    robbarker Posts: 1,367
    Are you sure the chain is actually slipping or could it be worn freehub pawls? Swap in another freehub from a known working bike and check. Come to that are the splines on the freehub body and cassette damaged?

    Derailleur properly installed, spring working OK? B screw adjusted properly and the tab against the stop OK?

    Jockey wheels rotate freely and not worn out, i.e pointy teeth?

    Indexing sounds like a the most likely suggestion though..

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