I fitted a new chain to my MTB. It was a KMC brand rather than the original shimano, but it was an 8 speed so should have been compatible. However, the chain slips a little when under tension and on the smallest rear cog. The chain length is OK in that the jockey wheel cage is vertical when it is supposed to be, So...is the cassette worn (in which case why doesn't it slip on the bigger cogs that I use more often) or have I goofed and bought an incompatible chain? Any advice welcome.
CityCyclingEdinburgh Forum » Questions/Support/Help
Slipping chain
(22 posts)- Started 10 years ago by Its_Me_Knees
- Latest reply from Cyclops
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Posted 10 years ago #
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Yeah, your cassette is likely to be worn out too. I generally replace cassettes at the same time as chains to prevent this very issue.
Posted 10 years ago # -
My cassettes usually wear out on the middle cogs? Not true that you always have to change chain and cassette, sometimes bit of filing of teeth required, I leave that to people who know what they are doing.
Sharking on the front cogs checked?
Posted 10 years ago # -
@gembo: er....sharking...?
Posted 10 years ago # -
Do the teeth on the front cogs look a bit more like shark fins than a new tooth would? Bit less symmetrical, bit curved??
Posted 10 years ago # -
Three options -
Less force using small cog until chain 'beds in' - ie wears!
New cassette.
Just replace small cog - may be a suitable one at Bike Station.
Posted 10 years ago # -
Ah, OK. No, they look OK...not sure how that would affect the performance of the rear cogs though....or is it just another sign of wear? The chain slips regardless of which front cog I'm on.
Posted 10 years ago # -
@chdot: I'm avoiding the small cog at the mo' so allowing it to bed in is no biggie for me (I use the MTB to commute over Edinburgh's various moonscapes). I also like this cheap option ;-)
All of the feedback thus far hasn't mentioned incompatibility, so would I be correct in thinking that, as long as I have 8 speed chain on an 8 speed cog, any brand will work?
Posted 10 years ago # -
"so would I be correct in thinking that, as long as I have 8 speed chain on an 8 speed cog, any brand will work?"
I'd say so - in spite of what Shimano may tell you..
Personally I think most chains are better than Shimano ones - but than may be dated prejudice...
I suspect there may be more genuine compatibility concerns with 10 and 11 speed systems.
Posted 10 years ago # -
KMC chains are a perfectly good replacement for a Shimano chain. Indeed, I'd say it's better. If your chain is slipping then as others have said it's highly likely to be a new cassette needed at the same time. I have yet to manage to replace a chain early enough before it has rendered the cassette also needing to be replaced. As chdot says, if the small cog is separate from the rest of the cassette, you might be able to get a (say) 12T one on its own rather than buying an entire cassette.
What I disagree with however is "bedding in" the new chain. This merely means that the chain will be worn away so that it works on the small worn out cog (assuming it is worn out). I'd prefer to keep my new chain in good nick by getting a cassette in good nick.
Posted 10 years ago # -
"What I disagree with however is "bedding in" the new chain. This merely means that the chain will be worn away so that it works on the small worn out cog"
Yes I was using "bedding in" slightly ironically. Some people say that chains "stretch" but that isn't really true either. All the tiny parts rub together and wear!
"I'd prefer to keep my new chain in good nick by getting a cassette in good nick."
This is where it gets 'interesting/'personal choice'. There is (said to be) a 'general consensus' that (if you don't run the chain for too long) you can get 'three chains per cassette'.
A worn chain will accelerate the teeth wear on the front rings too, but I'm not so sure that a new chain will be adversely affected by worn teeth on front or rear.
(Except perhaps if they've reached the shark's teeth stage.)
Posted 10 years ago # -
I be correct in thinking that, as long as I have 8 speed chain on an 8 speed cog, any brand will work?
Yes - I mix them quite a lot. KMC is used by many companies in combo with Shimano or SRAM blocks / ringsOther chain faults are stiff links on a new chain join. You'll have checked that?
It can be a very subtle fault. Put it into the the 11T and run it round backwards to see if any part of the chain lifts. On smaller sprocket is has to bend chain more. Of course it will also show in rear mech tensioner.
I would also say one chipped 11T tooth could be a problem but this has only happened since you introduced the new chain.
Take it to the Cycle Service or TBW maybe?
Posted 10 years ago # -
There is (said to be) a 'general consensus' that (if you don't run the chain for too long) you can get 'three chains per cassette'.
Yeah, this is what I've heard too. Never managed it! I'm still replacing them both at the same time. What exactly are you supposed to do to achieve this? Replace the chain early, or clean it mercilessly? Or something else?
Posted 10 years ago # -
" Replace the chain early, or clean it mercilessly? Or something else?"
Good questions.
Posted 10 years ago # -
at risk of double entendres - 'teenth, eighth, bigger..
If there's an 1/16th an inch over 12links of stretch, replace the chain, 1/8, chain and cassette, ,more than thi, chain, cassette and rings...
Since I know so little, an appeal to authority..
Posted 10 years ago # -
Nice. I shall need to obtain myself a steel ruler, methinks.
Posted 10 years ago # -
Have just clunked my way into work with exactly the same problem and now have the solution without even having to ask - this is a very efficient forum ;-)
Posted 10 years ago # -
Chain wear guides are available very cheaply. I have one and use it once a month.
http://www.chainreactioncycles.com/mobile/cyclo-chain-wear-indicator/rp-prod42815
Posted 10 years ago # -
@DaveC, Yes I use one of them. When it gets to 0.75% I make sure I've got a spare chain and when it hits 1% I replace it.
A chain seems to last about 500Km in the winter and more in the summer, but at least it's cheaper than replacing the rear sprocket.
Posted 10 years ago # -
I try to replace the chain before 0.75 so that I don't need to change the cassette. The aim is to keep the change to use again so I can get two chains per cassette. I don't always get this right - the last chain I let pass 0.75 - when I changed it without changing the cassette it was very skippy.
Posted 10 years ago # -
Posted 10 years ago #
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I try and change between 0.75 and 1% and normally get through 3 to 4 chains before I need to change the cassette. Brand new chains can have between 0.25 and 0.5% "stretch" due to the play in the chain to allow it to bend so I'm always a little wary of changing a chain too early before it needs done.
Posted 10 years ago #
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