Chain skipping

Arnaud said:

Hi all,

The chain on my touring bike is slightly skipping on a couple of rear
cogs (the 2 cogs above the smallest). It is quite subtle for the moment
but it's starting to get annoying.

I measured the distance between 12 links of the chain and it is slightly
above 12" by 1/10th of an inch. I don't know if 1/10th of an inch is
enough to cause the skipping but I think the chain has to be replaced.
From what I read I need to also replace the cassette. Is that all I
should replace or should I also change the front middle ring (the one I
use the most) ?

The chain has about 1500 miles of use, mostly during winter. I lubed it
quite often although I degreased it only 3 times. Is this normal to have
a worn chain after only 1500 miles??
The chain on my MTB lasted 5000 miles until I had to replace the whole
drivetrain...

Cheers,
Arnaud.

My suggestion would be to fit a new chain and see how it feels. If it
still doesn't feel quite right then buy a new cassette. If it still
doesn't feel right replace the jockey wheels in the mech etc etc. I
wouldn't rush out and buy a whole new drivechain, expecially if the
chain is only slightly overworn.

David Waters said:

My suggestion would be to fit a new chain and see how it feels. If it
still doesn't feel quite right then buy a new cassette. If it still
doesn't feel right replace the jockey wheels in the mech etc etc. I
wouldn't rush out and buy a whole new drivechain, expecially if the
chain is only slightly overworn.

Yup maybe just changing the chain will be enough...
Off to the LBS in the morning then 🙂

Thanks
Arnaud

Arnaud said:

The chain on my touring bike is slightly skipping on a couple of rear
cogs (the 2 cogs above the smallest). It is quite subtle for the
moment but it's starting to get annoying.

I measured the distance between 12 links of the chain and it is
slightly above 12" by 1/10th of an inch. I don't know if 1/10th of an
inch is enough to cause the skipping

Only if the cogs have already been well worn from previous chain(s).

Quoted message said:

but I think the chain has to be replaced.

Now will be a good time to change it anyway.

Quoted message said:

From what I read I need to also replace the cassette.

You wouldn't normally need to at this point with sprockets in good
condition but they won't be if the chain really is skipping over the
teeth. Check for stiff links in the chain, eliminate any gear shifting
problems and anything else you can think of.

Quoted message said:

Is that all I should replace or should I also change the front middle
ring (the one I use the most) ?

Chainrings outlast rear sprockets. Only change the chainring if a new
chain skips on it.

Quoted message said:

The chain has about 1500 miles of use, mostly during winter. I lubed
it quite often although I degreased it only 3 times. Is this normal
to have a worn chain after only 1500 miles??

Not exactly uncommon to elongate the chain by 1/10". But is this the
first chain with these sprockets? The chain shouldn't be skipping yet if
so.

Quoted message said:

The chain on my MTB lasted 5000 miles until I had to replace the whole
drivetrain...

You can normally do that or more mileage with road bike transmission as
well, it's just not a good idea to because chainrings are expensive and
they will eventually wear out like that.

Note. Excessive wear can be caused by crossing the chain over too much
(small-small, big-big, etc).

~PB

Arnaud said:

Yup maybe just changing the chain will be enough...

Nope, changing the chain alone will make the problem WORSE if the chain
really is skipping due to sprocket wear.

~PB

Pete Biggs said:

Chainrings outlast rear sprockets. Only change the chainring if a new
chain skips on it.

Why do chainrings outlast sprockets? For most of my cycling, the load
is shared between two chainrings but a whole stack of sprockets.

Are sprockets softer?

in message <[email hidden]>, Arnaud

(') said:

The chain on my touring bike is slightly skipping on a couple of rear
cogs (the 2 cogs above the smallest). It is quite subtle for the
moment but it's starting to get annoying.

New chain, new cassette, probably new chain-rings as well. It's a [censored].

Quoted message said:

From what I read I need to also replace the cassette. Is that all I
should replace or should I also change the front middle ring (the one
I use the most) ?

It's quite hard to see (with modern funny shaped teeth) exactly how worn
a chainring is. Without having seen yours, I would tend to, on the
precautionary principle, and the small one as well (because, having
fewest teeth, it wears fastest).

Quoted message said:

The chain has about 1500 miles of use, mostly during winter. I lubed
it quite often although I degreased it only 3 times. Is this normal to
have a worn chain after only 1500 miles??

I would say not. What make of chain, and what lubricant do you use?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Wise man with foot in mouth use opportunity to clean toes.
;; the Worlock

in message <[email hidden]>, David Waters

(') said:

Quoted message said:

I measured the distance between 12 links of the chain and it is
slightly above 12" by 1/10th of an inch. I don't know if 1/10th of an
inch is enough to cause the skipping but I think the chain has to be
replaced.

From what I read I need to also replace the cassette. Is that all I
should replace or should I also change the front middle ring (the one
I use the most) ?

My suggestion would be to fit a new chain and see how it feels. If it
still doesn't feel quite right then buy a new cassette.

The problem with that solution is that by the time you've desided you
need a new cassette you've already [censored] the new chain, so you'll need
another new chain, because if you don't get one you'll rapidly [censored] the
new cassette...

If any part of the drive train is significantly more worn than any other
it will hugely accelerate wear in the other components.

Replace them all at once. It's a [censored], it's expensive, but it's a _lot_
cheaper in the long run. And in future, monitor chain wear and replace
early with good quality chain.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I'd rather live in sybar-space

in message <[email hidden]>, Al C-F

(') said:

Pete Biggs said:

Chainrings outlast rear sprockets. Only change the chainring if a new
chain skips on it.

Why do chainrings outlast sprockets? For most of my cycling, the load
is shared between two chainrings but a whole stack of sprockets.

More teeth. The wear is shared out equally among the teeth of the
sprocket, so each of the teeth on an eleven tooth sprocket will get
four times the wear of each of the teeth on a 44 tooth sprocket.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

...but have you *seen* the size of the world wide spider?

Simon Brooke:

Quoted message said:

More teeth. The wear is shared out equally among the teeth of the
sprocket, so each of the teeth on an eleven tooth sprocket will get
four times the wear of each of the teeth on a 44 tooth sprocket.

Except on a road bike you'd be more likely to be running the chain on a 48
or 50 or 52 tooth chainring when it's on the 11 tooth rear sprocket, so the
difference is even greater.

However, the big chainring would get considerably more than four times the
use of an 11 tooth sprocket on any bike ridden by me (not that I have such a
thing - 52*14 is quite a big enough gear for my knees, thanks), so that
would even out the wear a bit, which is what the previous poster was getting
at, I think.

And yet the smaller sprockets *do* wear faster, even with less use - I think
I know why, but I couldn't begin to explain it. Something to do with torque.
I expect Sheldon Brown probably has something about it on his site.

d.

Al C-F said:

Quoted message said:

Chainrings outlast rear sprockets. Only change the chainring if a
new chain skips on it.

Why do chainrings outlast sprockets? For most of my cycling, the load
is shared between two chainrings but a whole stack of sprockets.

It's mainly because they're larger (on a road bike at least). I think
being at the *front* might make a difference as well, though I don't
understand why.

Quoted message said:

Are sprockets softer?

Nope, usually harder!

~PB

Al C-F <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Pete Biggs said:

Chainrings outlast rear sprockets. Only change the chainring if a new
chain skips on it.

Why do chainrings outlast sprockets? For most of my cycling, the load
is shared between two chainrings but a whole stack of sprockets.

1. The sprockets go round more times than the chainrings so get more
wear.

2. Chainrings generally do not give problems until they are quite
badly worn. Rather than skipping, when they do finally wear out the
chain will tend to jam or "suck" (i.e. fail to disengage at the
bottom) especially when changing gear from a larger ring to a smaller
one. This can actually be quite dangerous.

--
Dave...

Dave Kahn said:

2. Chainrings generally do not give problems until they are quite
badly worn. Rather than skipping, when they do finally wear out the
chain will tend to jam or "suck" (i.e. fail to disengage at the
bottom) especially when changing gear from a larger ring to a smaller
one. This can actually be quite dangerous.

Chain can skip on chainrings as well. I think chain suck is more common
on MTB chainsets, with the smaller rings.

~PB

"Pete Biggs" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Al C-F said:

Quoted message said:

Chainrings outlast rear sprockets. Only change the chainring if a
new chain skips on it.

Why do chainrings outlast sprockets? For most of my cycling, the load
is shared between two chainrings but a whole stack of sprockets.

It's mainly because they're larger (on a road bike at least). I think
being at the *front* might make a difference as well, though I don't
understand why.

The pressure load at the front is shared over many more teeth. The wear is a
nonlinear function of the pressure on the teeth.

Quoted message said:

Quoted message said:

Are sprockets softer?

Nope, usually harder!

Depends. If they are hard, they are generally case hardened. Once the hardened
layer wears through, the softer metal beneath wears very rapidly.
--
"To live in San Francisco and just not care that
there are naked triathletes running across
your lawn, that's just a waste of exhibitionism."
- Kibo

Mark South said:

Quoted message said:

It's mainly because they're larger (on a road bike at least). I
think
being at the *front* might make a difference as well, though I don't
understand why.

The pressure load at the front is shared over many more teeth. The
wear is a nonlinear function of the pressure on the teeth.

Yes but what about when the chainring happens to be *smaller* than the
largest rear sprockets (as in the case with some triple inner chainrings)?
I think they still wear slower in that case as well.

Quoted message said:

Quoted message said:

Quoted message said:

Are sprockets softer?

Nope, usually harder!

Depends. If they are hard, they are generally case hardened. Once
the hardened layer wears through, the softer metal beneath wears very
rapidly.

Chainrings are often aluminium. Rear sprockets are usually steel. Just
have a go at filing them if you doubt which are harder.

~PB

On Tue, 18 May 2004 19:03:37 +0100, "Pete Biggs"
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Chainrings are often aluminium. Rear sprockets are usually steel. Just
have a go at filing them if you doubt which are harder.

Maybe wear particles become embedded in the soft material, causing it
to wear the chain rather than the chain to wear it?

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington University

"Pete Biggs" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Mark South said:

Quoted message said:

It's mainly because they're larger (on a road bike at least). I
think
being at the *front* might make a difference as well, though I don't
understand why.

The pressure load at the front is shared over many more teeth. The
wear is a nonlinear function of the pressure on the teeth.

Yes but what about when the chainring happens to be *smaller* than the
largest rear sprockets (as in the case with some triple inner chainrings)?
I think they still wear slower in that case as well.

Well, ride around for a few months in your 22x34 gear, measure the wear and
report back :-)

Quoted message said:

Quoted message said:

Quoted message said:

> Are sprockets softer?

Nope, usually harder!

Depends. If they are hard, they are generally case hardened. Once
the hardened layer wears through, the softer metal beneath wears very
rapidly.

Chainrings are often aluminium. Rear sprockets are usually steel. Just
have a go at filing them if you doubt which are harder.

A. Case-hardened aluminium can be way harder than mild steel.
B. Filing is a very poor way to judge hardness - titanium, for example, cannot
be made much harder (without being ridiculously brittle) than around 48-50 Rc,
but filing it is a pain because it work-hardens under the file and the soft bits
that do go into the file clog the teeth. This is what Rockwell gauges are for.
C. Actual hardness does relate very well to wear resistance though.
--
Mark South
Citizen of the World, Denizen of the Net
<<Tiens! Ce poulet a une grenade!>>

"Just zis Guy, you know?" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Tue, 18 May 2004 19:03:37 +0100, "Pete Biggs"
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Chainrings are often aluminium. Rear sprockets are usually steel. Just
have a go at filing them if you doubt which are harder.

Maybe wear particles become embedded in the soft material, causing it
to wear the chain rather than the chain to wear it?

Chain steel is probably the hardest stuff on your bike apart possibly from the
ball bearings. Chains as a consequence can be brittle - most of us have seen
chain plates fail catastrophically.

But frankly, it's less work to replace one's chain every 3000 km than it is to
try to work out what the wear patterns are....
--
Mark South
Citizen of the World, Denizen of the Net
<<Tiens! Ce poulet a une grenade!>>

In article said:

Mark South said:

Quoted message said:

It's mainly because they're larger (on a road bike at least). I
think
being at the *front* might make a difference as well, though I don't
understand why.

The pressure load at the front is shared over many more teeth. The
wear is a nonlinear function of the pressure on the teeth.

Yes but what about when the chainring happens to be *smaller* than the
largest rear sprockets (as in the case with some triple inner chainrings)?
I think they still wear slower in that case as well.

Probably used less in those cases.

Mark South said:

A. Case-hardened aluminium can be way harder than mild steel.
B. Filing is a very poor way to judge hardness - titanium, for
example, cannot be made much harder (without being ridiculously
brittle) than around 48-50 Rc, but filing it is a pain because it
work-hardens under the file and the soft bits that do go into the
file clog the teeth. This is what Rockwell gauges are for. C. Actual
hardness does relate very well to wear resistance though.

Thanks for the info. Which make/model chainrings use case-hardened
aluminium?

~PB