On 2017-09-15 05:59, Dennis Davis wrote:
In article ,
John B. wrote:

...

There seems to be three options. One, to use a ruler and measure from
pin to pin. Two to use a chain tool and measure from roller to roller.
Or three, to use some combination of the two.

Or perhaps there is a fourth - ignore the whole thing as a tempest in
a tea pot :-)

Chains are half an inch pitch. Put the chain under tension and
measure 24 links. At 12 and one eighth inches you're looking at 1%
elongation and you're likely to need to replace both the chain and
sprockets at the same time. At 12 and one sixteenth inches you're
at 0.5% elongation and you're likely to just need to replace the
chain.


That's how I monitor it. Why buy a chain gauge when one already has a
sufficiently long ruler? After I clean a chain and before lubing it I
put a little pull on the chain by leaning my hand on a pedal, then hold
the ruler with the 0" mark to a link edge and read the value 12" down
the chain. I let my chains to about 0.8% which IME still allows same
cassette use. One chain accidentally went to 1% on a long hilly and very
dirty MTB ride (with KMC X10.93 it seems the wear accelerates a lot
towards the end) and that ruined the cassette.


Looks like I need to replace both the sprockets and chain on my
hybrid bike :-(

If your chainstays are short, you may need to measure just 20 links
and work with tenths and twentieths for the elongation.

Bear in mind that most riders will mainly use a few sprockets.
Those at the extreme end of the cassette get less use. You may find
the much used sprockets will not run well with a new chain even if
the old chain did not appear to have worn too much.


With many the cogs can be turned around which requires dremeling off
part of the wider spline for HG cassettes. Fast shifting is gone then
but on a road bike that never mattered much to me.

--
Regards, Joerg

http://www.analogconsultants.com/