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New chain keeps slipping under load

Duncan0506Duncan0506 Posts: 7
edited February 2010 in MTB general
Hi guys,

Had my 2008 Specialized Hardrock Pro Disc for just under a year now, and so far there's been no major problems... Up until now.

Over the winter, anytime I went out for a ride I didn't clean my chain, and due to the salt on the roads the chain corroded quite severely so when the weather cleared up I decided to replace it.

The old chain was a KMC X8 1/2" x 3/32" w/ Reusable Master Link, and I replaced it with a KMC 'X8-93' 8 speed chain, and now for some reason the chain keeps 'slipping' under any load in any gear.

The only difference between the old and new chain I can spot is that the new one is 2 or 3 links longer, but the derailleur still has plenty of clearance in the lowest gear, so I'm not sure if this would affect anything.

Any help or further questions would be greatly appreciated :)

Posts

  • delcoldelcol Posts: 2,848
    did you change your casset as well the casset may be worn causing the chain to slip..

    also have you shortened the chain. you are suposed to knock a few links out of new chains.. measure it against the old one..
    you tube has video showing you how to set up the drive chain...

    i bet it will be the rear casset thats causing you the problem.
  • No I haven't replaced the cassette although some of the teeth have signs of wear on the side that is in contact with the chain, so would it be a good idea to change the cassette?

    I'll try shortening the chain as well to rule that out.
  • delcoldelcol Posts: 2,848
    the chainring and casset wear over time especially if the drivetrain is neglected, the more you clean the chain and lube it the longer it should last..

    grit gets in the chain and acts as a grinding paste on the drivetrain.. look at the teeth are they showing signs of wear ie do they look like a sharks fin.. if so then there's every chance that the casstet needs to be replaced to.. possably the chain rings to...
  • petejukpetejuk Posts: 235
    Although excessive wear of the cog teeth can cause some slippage in extreme cases, it is most likely that your new chain is too long. As you place load on it, the rear mech spring does not take up sufficient tension and therefore causes it to slip. If you still have your old chain, measure the new one against it and shorten it to the same length.
    Ideally, replacing the rear cassette and the chain together means that you get the most wear out of both items as they wear at the same rate. The shifting will be smoother and crisper too. I do recommend you shorten the chain first though.
  • richg1979richg1979 Posts: 1,087
    its deffo the cassette, change it and all will be fine, ive got a box full of cassettes that look fine but wont take a new chain.

    nothing to do with chain length, as long as theres still tension on rear mech it shouldnt slip.
  • ilovedirtilovedirt Posts: 5,798
    richg1979 wrote:
    its deffo the cassette, change it and all will be fine, ive got a box full of cassettes that look fine but wont take a new chain.

    nothing to do with chain length, as long as theres still tension on rear mech it shouldnt slip.
    how do you know it's the cassette and not the chainrings?

    It's called chainsuck, basically it means some other part of your drivetrain is worn too, either the cassette or one or more of the chain rings. Have a look them, if the teeth have started to look hooked on one side, it means it needs replacing.
    Production Privee Shan

    B'Twin Triban 5
  • ilovedirt wrote:
    richg1979 wrote:
    its deffo the cassette, change it and all will be fine, ive got a box full of cassettes that look fine but wont take a new chain.

    nothing to do with chain length, as long as theres still tension on rear mech it shouldnt slip.
    how do you know it's the cassette and not the chainrings?

    It's called chainsuck, basically it means some other part of your drivetrain is worn too, either the cassette or one or more of the chain rings. Have a look them, if the teeth have started to look hooked on one side, it means it needs replacing.

    Pretty sure chainsuck is where the chain doesn't disengage from the chainring causing the chainset to come to an unexpectedly abrupt halt.
  • richg1979richg1979 Posts: 1,087
    edited February 2010
    chainsuck? wtf you on about??? his chains slipping not getting pulled round by front rings wich is CHAINSUCK!

    and the cassette teeth dont need to be hooked for it to be worn out.

    its all to do with radial contact points between the chain roller seats in the sprockets and the chain rollers.
  • richg1979richg1979 Posts: 1,087
    ilovedirt wrote:
    richg1979 wrote:
    its deffo the cassette, change it and all will be fine, ive got a box full of cassettes that look fine but wont take a new chain.

    nothing to do with chain length, as long as theres still tension on rear mech it shouldnt slip.
    how do you know it's the cassette and not the chainrings?

    It's called chainsuck, basically it means some other part of your drivetrain is worn too, either the cassette or one or more of the chain rings. Have a look them, if the teeth have started to look hooked on one side, it means it needs replacing.

    Pretty sure chainsuck is where the chain doesn't disengage from the chainring causing the chainset to come to an unexpectedly abrupt halt.

    exactly.
  • ilovedirtilovedirt Posts: 5,798
    alright then i'm getting my terms mixed up, no need to be an censored . You still didn't answe my question though - how do you KNOW it's the cassette without even taking a look at his bike?
    Production Privee Shan

    B'Twin Triban 5
  • richg1979richg1979 Posts: 1,087
    because its a very common prob when fitting a new chain to a used cassette.
    ive got about 6 cassettes that all look mint but slip with a new chain.

    its usually sram ones i find the worst.

    i am 99.9% sure its the cassette if by the unlikly chance im wrong i will bow my head in shame and apologise.
  • ilovedirtilovedirt Posts: 5,798
    i've had it happen with chainrings before too
    Production Privee Shan

    B'Twin Triban 5
  • richg1979richg1979 Posts: 1,087
    ive not had it with a chainring unless the chainring actually looks worn, but its poss with a granny ring, its usually the smaller rings that are affected the worst as theres less contct points with the chain.
  • ilovedirtilovedirt Posts: 5,798
    i use my middle ring a lot, i mean i did probably a thousand miles or maybe two on it, back when i had a paper round and rode 4 miles or so every night for two years on the same old beater bike!
    Production Privee Shan

    B'Twin Triban 5
  • supersonicsupersonic Posts: 82,708 Lives Here
    I do see this often with chainrings - the chain will slide over the teeth.
  • .blitz.blitz Posts: 6,588
    It's surprising how little force the chain needs to disengage. Some morons have been known to put the middle ring on the wrong way round and then the chain comes off very quickly (and painfully) under load hahahahahaha *ahem* :oops:
  • Sirius631Sirius631 Posts: 1,015
    I'm astounded that nobody has mentioned the method of balancing chain/cassette wear that is common within the road community. Considering the price differential between chains and cassettes, it is wise not to have waste a cassette every time you bin a chain.

    As a worn chain wears out a cassette faster it is wise to change the chain early, before the cassette is unable to take a new chain. When I buy a new cassette, I buy 3 chains aswell. After a couple of months I swap chain 1 out for chain 2, swap chain 2 for chain 3 a couple of months later, and return to chain 1 another 2 months down the line. I expect to go through three rotations of chain installation before all the chains reach their full stretch. This way a cassette will run with a new cassette for a third of its life, and the chains and cassette will be only 1/3rd of the way through their life after 6 months, rather that half way through.
    To err is human, but to make a real balls up takes a super computer.
  • dresbodresbo Posts: 129
    On the subject of chain/cassette wear, personally I find it much more economical to wear out both a chain and cassette together until they are both totally worn and then replace the two. It's great changing your chain when it's stretched but a new chain is only just less than the cost of a cassette (depending on what you get of course) and if you keep the two matching worn parts together I find they last easily as long as two chains take to stretch. Plus you get a brand new cassette each time you change.

    each to their own
  • cgarossicgarossi Posts: 729
    Might be a daft question, but you did route the chain properly?

    Some people route the chain through the jockey wheels in front of the metal tab, when it should be behind. This can cause the appearance of chain slip when actually its just the tab getting caught on the chain.
  • FSR_XCFSR_XC Posts: 2,258
    Duncan0506 wrote:
    Hi guys,

    The old chain was a KMC X8 1/2" x 3/32" w/ Reusable Master Link, and I replaced it with a KMC 'X8-93' 8 speed chain, and now for some reason the chain keeps 'slipping' under any load in any gear.

    The only difference between the old and new chain I can spot is that the new one is 2 or 3 links longer, but the derailleur still has plenty of clearance in the lowest gear, so I'm not sure if this would affect anything.

    Any help or further questions would be greatly appreciated :)

    Firstly, you should fit the new chain with the same number of links as the old one.

    You say it slips in any gear . . . . is this any gear on the rear cassette or on the front chainrings?

    Often people use middle ring for just about all of their riding. It is therefore not uncommon for a middle ring to wear quite quickly, especially if you tend to put a lot of load through your pedals (as opposed to using high cadence).

    Stick the front in granny ring and see if it still 'slips' in every gear. If it does, it's the cassette.
    Do the same with middle and then outer rings. If it only 'slips' in granny or middle, it's that chainring.

    It is good practice to change the chain and cassette together or as has been mentioned, swop chains to extend the life of the cassette. So even if it is the chainring, it won't be a bad idea to change the cassette too.
    Stumpjumper FSR 09/10 Pro Carbon, Genesis Vapour CX20 ('17)Carbon, Rose Xeon CW3000 '14, Raleigh R50

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  • supersonicsupersonic Posts: 82,708 Lives Here
    Measure chain the normal way - around the two biggest cogs, bypassing the mechs and add two full links.
  • colintravcolintrav Posts: 1,074
    My chain kept slipping and all i did to rectify it was by tightening the gear cable


    It would slip if I used 1,2,3 ...and in 10th
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