Chain wear

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olon1968
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Chain wear

Postby olon1968 » 17 Feb 2007, 9:47am

After how many miles should I replace my chain in order to minimze wear on other components? I am using Campag Veloce 2006 10spd which I clean and lube weekly. Thanks.

Jimbo

Postby Jimbo » 17 Feb 2007, 10:58am

You can measure it to see how much it has "stretched"

Here is a good place to start:
http://www.sheldonbrown.com/chains.html

reohn2

Postby reohn2 » 19 Feb 2007, 9:06am

I use a Park chain measuring tool for convenience,they cost about £7,just keep checking it with the tool every month and change the chain when the tool shows its worn,you'll get more life out of your cassette that way.

PW
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Postby PW » 22 Feb 2007, 9:37pm

The tools are unreliable, our friend Mr Biggs on another site hates them with a passion. Measure the pins centre to centre with a steel tape. The pins are set at 1/2" centres when new. When a nominal foot length measures 12 1/16" bin it. That will ensure the cassette is undamaged & can be re-used with the next chain. If you allow the chain to go beyond that measurement the new chain will skip on the old cassette. If the chain is allowed to wear to the point where a nominal foot length measures 12 1/8" the chainset will start to suffer too - then things really become expensive! :(

thirdcrank
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Postby thirdcrank » 23 Feb 2007, 8:43am

The tools may be unreliable (but in the absence of an explanation, I cannot see how.) I have a Rohloff Kaliber (of which the current Park offering is a thinly disguised copy.) It seems to work perfectly for me. Having faffed about over the years measuring chains, I would say that although a steel rule is obviously infallible, a human being such as me using one is not. Also, wear can be uneven, especially on a cheaper chain that has got wet a couple of times. With a measuring tool, it is possible to go quickly round the whole chain and check at intervals of 3-4 links. Accurate, repeated measuring with a ruler might be tedious.

In the end, it is individual choice.

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Simon L6
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Postby Simon L6 » 23 Feb 2007, 8:48am

my answer to this is always the same. Change the lot (cassette, chain, chainrings as neccessary) at the same time, and do it in spring, irrespective of the wear.

No drive is in good shape after the winter, and changing a chain on its own simply gives you slippage.

reohn2

Postby reohn2 » 23 Feb 2007, 9:20am

I'm with T/C on this my chain tool has worked ok for me I can remember getting four or five chains out of our old Dawes Galaxy twin before we changed the rear freewheel.The Thorn tandem on the last cassette went through three chains but it had an XTR cassette and i don't think they're as durable as the cheaper options due to their lightweight construction.The mileage for the XTRcasstte was 4800mls from memory but that was all weathers and a tandem is a bit heavier on drivetrains than solos.

It would be interesting to know what others get out of their drivetrains along with their cleaning regemes.

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andrew_s
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Postby andrew_s » 23 Feb 2007, 11:25pm

thirdcrank wrote:The tools may be unreliable (but in the absence of an explanation, I cannot see how.)

The problem with the Park/Rohloff type of measuring tool is that they don't measure the distance between pin centres, but between the front of one roller and the back of the one 3 or 4 chain links further on.
There's a variable amount of slop between the roller and the pin/inner plate bushings that the tool has to try and take into account.

The upshot is that with some makes of chain, a new one fresh out of the box can show up as being half worn out.

(apparently) - I take the same approach as SimonL6, so I've not gone around checking.

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Mick F
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Postby Mick F » 24 Feb 2007, 8:52am

I don't have a tool, can't see the reason to going to the (small) expense. As for replacing the whole lot, sprockets and all, it's a bit over the top. If the chain is kept clean, replaced early enough, sprockets will last for years.

I use a long steel rule to check the length when the chain's off for cleaning.

Mick F. Cornwall

thirdcrank
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Postby thirdcrank » 24 Feb 2007, 9:24am

andrew_s wrote:The problem with the Park/Rohloff type of measuring tool is that they don't measure the distance between pin centres, but between the front of one roller and the back of the one 3 or 4 chain links further on.
There's a variable amount of slop between the roller and the pin/inner plate bushings that the tool has to try and take into account.


The damage caused by a worn chain is because of the tooth wear when the rollers grow further apart and bite more deeply into the leading edge of each tooth. It seems to me, therefore, that gauges are more, rather than less likely to do the job. I can believe that Rohloff' as chain manufacturers, will want to sell more chains, rather than less, but so long as they are erring on the side of caution, that seems OK to me. But as I said, there is no compulsion, there is a choice of method.

reohn2

Postby reohn2 » 24 Feb 2007, 10:31am

Measuring inbetween the rollers is better than measuring the pin distances with a steel rule because it is the rollers that are in contact with the sprockets and it is the distance between rollers to sprocket interface that gives a true wear indication.Or am I missing something.
That said dirty chains wear out quicker and also wear out sprockets faster IMHO
If I could find a lube that a)doesn't wash off easily b)doesn't truly attract road dirt. my drivetrains would last a lot longer.
As it is regular cleaning and lubing is the only way to keep wear to a minimun.

KEELIEDW
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Postby KEELIEDW » 8 Mar 2007, 2:59pm

The longer the chain length which you can measure the better.
If the chain's off, hang it up & measure as great a length as possible,do the simple maths comparing the actual length versus the theoretical, divide the difference by the number of links & see if you're within tolerance.
I've given up cossetting chains with expensive lubes & cleaners, especially in winter. I simply fit a new basic Sedis chain (around £5 ) , and bin the old one, at least twice per year.

PW
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Postby PW » 9 Mar 2007, 10:50am

I find the modern (9speed & up) chains last more miles than the old type 6 speed ones. Given that the lubrication regime is the same I'll hazard a guess it's due to designed in improvements in flexibility. Exact mileages vary according to type of riding & geographical location, amongst others but I used to trash a 6 speed chain (triple chainset) in just over 1,000 miles. The 9 speeds are running 1,300+ with no damage to the cassette.

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Mick F
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Postby Mick F » 15 Mar 2007, 12:03pm

I've just taken off my Campag 9sp chain and cassette for a good cleaning.

I gave the chain a good measuring too. Spot on. 3,800 miles done with that chain and that cassette.

I clean the lot, and lubricate, every month or so, or as the fancy takes me.

White Lightning is a great lub.

Mick F. Cornwall

George Riches
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Postby George Riches » 23 Jul 2007, 6:02pm

A variation on the steel rule method of chain measurement.
Image

To minimise sag, I 've put the chain on the biggest sprockets.

Perhaps not quite as quick as the Park/Rohloff tool, but you do get a good record if you take a high resolution photograph. With use of a flash it's easy to read the ruler's markings by viewing the image on a computer screen. With a few photographs taken at various stages of a chain's life, you might be able to make a good estimate of when the chain will be nearing the 0.75% limit.

My experience with chains:
Image

I've unhappy about that last one. A TaYa TB50 (the dirty one in the image below). The others were Sram PC48 or KMC Z-78.

When the chain is off the bike I measure it against a virgin chain. To do this I use a wooden stick with a nail at one end and a screwed down plastic ruler at the other:
Image

This arrangement allows accurate measurements to be quickly made.