Chain "Stretch"

baccaman21

Is there a simple method to determine if a chain has reached the end of it's life?

I understand there's a tool you can buy that measures the 'stretch' - but what exactly does it measure and could I use a tape measure or another more accurate measuring tool?

ta

nicklouse

12 links = 12" as new.

baccaman21

k... and how far beyond 12" would be considered too far...

supersonic

Above 1/16th of an inch then its on its way. 1/8th plus and its shagged.

baccaman21

mmm Kthnx chaps!

stumpyjon

IMHO just get the park tools chain checker, about £ 7. It's dead easy to use, you hook one end into a link and then see if the other end will fit into a link further up the chain. It's double sided, if side 1 fits in but side 2 doesn't the chains on it's way out and if side 2 fits as well the chains knackered (automatically works to the tolerances Supersonic mentionned).

Takes about 2 seconds to check and is dead simple (it's what called a go / no go gauge), no measuring just fits or it doesn't so it's probably more accurate than any form of measuring device. It's the sort of thing we try and use at work for quality checks, no measuring, no mistakes, no ambiguities (might have guessed I like my chain checker) .

baccaman21

granted... but £7 for tool and a no fiddling... or no cost for some fiddling and a steel rule (that's in my tool kit anyway) or that micrometer I knicked from my dads tool box years ago is a no cost fix that works just as well...

but thanx for the advice...

supersonic

You gotta get the chain very straight though!

TBH I have never measured a chain in my life. If the shifting starts to go to pot, and I know its nothing else, then its new chain time. Changing cassettes or chainrings require a new chain anyway.

baccaman21

ah... that's where my 2 midget fettling gimps come in handy. They hold the chain from each end and pull it tight over the counter top and hey presto... straight as a die...

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:oops:

but yeah... I get ya point.

stumpyjon

I just like tools, the more specialist the better :twisted:

supersonic

I like my chain removal tool - a pair of bolt croppers!

MilitantGraham

As a rough guide;
Shift to the biggest chain ring,
Hold the chain at the front part of the chainring and pull it.
If you can see a whole tooth showing, the chain is worn out.

clanton

With reference to the chain meauring tool above - I have the PArk tools one which is double sided etc and checked my road bike chain with it which was fine on both. However when I had the bike checked over prior to a big ride by the LBS they used their own chain tool and said the chain was well worn. So is there a difference between various chains ie 9 spd vs 10 spd?

ride_whenever

I'd use the park one, or get a cheapo imitation one, and if you replace at an eighth stretched then you often can get two chains to one cassette

JamesB

Park tool well worth it...I used to use a tape and measure the chain but for £7 so easy and simple, just make sure though chain is gently stretched (ie put gentle pressure on pedals and measure on taut chain).