Chain woes.

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bigjim
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Location: Manchester

Chain woes.

Postby bigjim » 30 Jun 2019, 5:11pm

This week the 8 speed chain keeps jumping on high cogs. 11 and 13 I think. Check the chain and it's worn. Replaced with new chain and re-indexed gears. It's still jumping! Ok. Worn cassette. But on inspection the teeth on said cogs look fine. Just as square as all the others. Can teeth look ok and still be worn?
Thanks. Jim.
Nothing left to prove.

alexnharvey
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Joined: 10 Jan 2014, 8:39am

Re: Chain woes.

Postby alexnharvey » 30 Jun 2019, 5:16pm

Yes, it doesn't take much wear, especially on the small sprockets. You really need to put an unworn one right next to see it. I think there are some pictures on the forum which do just that.

reohn2
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Joined: 26 Jun 2009, 8:21pm

Re: Chain woes.

Postby reohn2 » 30 Jun 2019, 5:25pm

alexnharvey wrote:Yes, it doesn't take much wear, especially on the small sprockets. You really need to put an unworn one right next to see it. I think there are some pictures on the forum which do just that.

Due to to chainwrap on not many teeth
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Brucey
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Re: Chain woes.

Postby Brucey » 30 Jun 2019, 5:29pm

it only takes a few microns of wear on the sprockets to make it so that a new chain won't run right. If the affected sprockets are ones you don't use much then you have little to lose by running the chain for a few hundred miles and seeing if it all settles down or not.

However that the old chain was skipping on the sprockets is a bit odd; normally they don't do that; possibly there is another fault (eg not enough tension in the chain because the derailleur is binding, or something...?).

cheers
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bigjim
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Location: Manchester

Re: Chain woes.

Postby bigjim » 30 Jun 2019, 7:21pm

Brucey wrote:it only takes a few microns of wear on the sprockets to make it so that a new chain won't run right. If the affected sprockets are ones you don't use much then you have little to lose by running the chain for a few hundred miles and seeing if it all settles down or not.

However that the old chain was skipping on the sprockets is a bit odd; normally they don't do that; possibly there is another fault (eg not enough tension in the chain because the derailleur is binding, or something...?).

cheers

I blamed the old chain at first as when I used the chain checker it was well over the 75 limit. I'll investigate fuirther using the above advice.
Thanks.
Nothing left to prove.

mercalia
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Re: Chain woes.

Postby mercalia » 30 Jun 2019, 8:14pm

bigjim wrote:So this week the 8 speed chain keeps jumping on high cogs. 11 and 13 I think. Check the chain and it's worn. Replaced with new chain and re-indexed gears. It's still jumping! Ok. Worn cassette. But on inspection the teeth on said cogs look fine. Just as square as all the others. Can teeth look ok and still be worn?
Thanks. Jim.


I am surprised you say that. On my Shimano 8 speed cassettes the teeth on the very smallest sprockets are shaped as if they are worn ( but they aint), they aint and never were like the bigger sprockets. What brand are you using?

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bigjim
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Location: Manchester

Re: Chain woes.

Postby bigjim » 30 Jun 2019, 9:54pm

mercalia wrote:
bigjim wrote:So this week the 8 speed chain keeps jumping on high cogs. 11 and 13 I think. Check the chain and it's worn. Replaced with new chain and re-indexed gears. It's still jumping! Ok. Worn cassette. But on inspection the teeth on said cogs look fine. Just as square as all the others. Can teeth look ok and still be worn?
Thanks. Jim.


I am surprised you say that. On my Shimano 8 speed cassettes the teeth on the very smallest sprockets are shaped as if they are worn ( but they aint), they aint and never were like the bigger sprockets. What brand are you using?

I don't know as it's a while since I changed one. I imagine Shimano. It's an 11-34. But yes definitely square with that slight curved indent on the front face like all the other sprockets..
Nothing left to prove.

philvantwo
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Joined: 8 Dec 2012, 6:08pm

Re: Chain woes.

Postby philvantwo » 30 Jun 2019, 11:02pm

8 speed??
We're up to 11 speed now chaps!! :lol: :lol: :lol:
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francovendee
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Joined: 5 May 2009, 6:32am

Re: Chain woes.

Postby francovendee » 1 Jul 2019, 7:48am

philvantwo wrote:8 speed??
We're up to 11 speed now chaps!! :lol: :lol: :lol:

I must have lost 3, off to the shed now to take a look for them 8)

gxaustin
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Re: Chain woes.

Postby gxaustin » 1 Jul 2019, 11:44pm

it only takes a few microns of wear on the sprockets to make it so that a new chain won't run right.


I've seen this said more than once. If so why have I never worn out a cassette? Some of mine must have clocked up well over 10.000mls. I can't believe that they have worn by less than a few microns, bearing in mind that a micron is one thousandth of a millimetre. My gear changing is fine with a new or worn chain.

Brucey
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Re: Chain woes.

Postby Brucey » 2 Jul 2019, 12:48am

gxaustin wrote:
it only takes a few microns of wear on the sprockets to make it so that a new chain won't run right.


I've seen this said more than once. If so why have I never worn out a cassette? Some of mine must have clocked up well over 10.000mls. I can't believe that they have worn by less than a few microns, bearing in mind that a micron is one thousandth of a millimetre. My gear changing is fine with a new or worn chain.



Sprockets can wear but if they wear in the right way they don't wear out, or at least don't wear in such a way as a new chain will definitely skip.

There are quite a few factors at work; one is which sprockets you favour, another is how hard you push on the pedals.

cheers
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Sweep
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Re: Chain woes.

Postby Sweep » 2 Jul 2019, 5:41am

philvantwo wrote:8 speed??
We're up to 11 speed now chaps!! :lol: :lol: :lol:

Not sure what your point is.
Or who "we" is.
Have just built up an 8 speed. It's great.
Do enjoy your 13 speed.
Sweep

pwa
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Re: Chain woes.

Postby pwa » 2 Jul 2019, 7:58am

philvantwo wrote:8 speed??
We're up to 11 speed now chaps!! :lol: :lol: :lol:

2x11=22
3x8=24
I'm up to 27 now (3x9) and have been for many years. Catch up! :lol:

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Mick F
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Re: Chain woes.

Postby Mick F » 2 Jul 2019, 8:24am

I'm on 10 x 3 x 3 = 90 .............. come on guys, catch up! :lol:
Mick F. Cornwall

Ant...
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Location: Denbighshire

Re: Chain woes.

Postby Ant... » 2 Jul 2019, 8:57am

90 gears, nothing, i'm on pinion box and rolhoff hub 18x14=252!