year as I mechanic across the country I throw away dozens of cog sets and
chainrings whose life could have been extended with a little bit of
attention…mainly attention to the chain.
Chain wear is inevitable but it shouldn’t ruin your whole drive train
if you keep it clean, lubricated, inspect it regularly, and replace the chain
before it damages other components.
The first step in
maintaining a smooth shifting system and giving it a long life is to keep it
clean and well lubricated. No one
will argue the importance of lubrication, but many people neglect the cleaning
process. Simply lubricating a chain
over and over without cleaning eventually becomes counterproductive as it
attracts dirt and grit. Grit
multiplies the natural wear and tear on these moving, rubbing parts.
This grit gets into the pins of the chain and expedites their wear as
they travel thousands of times around the cogs and chainrings.
The result is chain stretch and excessive chain side flex.
The side-flex will eventually affect smooth shifting, as the chain will
get sloppy as side forces are put on it by the shift system. Chain stretch (the medal doesn’t really stretch, but the
chain actually becomes longer as these pins wear so they are farther apart) will
begin to wear the cogs and chainrings to match the longer chain.
This ruins these components very quickly.
Cleaning will extend the
life of the chain but replacing the chain regularly will extend the life of the
rest of the drive train. Neglect of
this process can ruin an expensive drive system within 3000-4000 miles.
What’s a regular basis? It
depends on how well you kept it clean and what conditions you ride in.
I recommend changing approximately every 2000 miles or so for roadies (maybe sooner if
you don’t keep the chain clean), or anytime you start finding “stretch.”
If you replace the chain before it starts to stretch, you keep the
other parts (cogs, pulleys, and chainrings) wearing against a good chain (one
that’s not stretched). To keep
explanations simple, this keeps the spacing of the teeth constant.
If you replace the chain regularly, you will get longer life on the other
components. Replacing the chain
regularly is not only good preventative maintenance it’s also the least
expensive option since you’ll be able to do it several times before you have
to replace the cogs, and even more times before replacing the chainrings.
Wait too long to replace the chain and you may have to replace the whole
shooting match…that costs bucks!
How do you check for
chain stretch you ask? It’s easy.
You can buy a chain stretch tool from a parts catalog or bike shop.
This tool will indicate when it’s time to replace the chain. Or if you are cheap like me, you can measure the chain.
To do this, lock the rear brake and put pressure on the pedals to tighten
the chain. Then measure the
distance between the chain pins with a ruler (measure the section of chain
that’s under stress...on top of the cogs to the top of the large chainring).
Put “0” on the center of a pin and then look at the “12 inch”
mark. The pin at the one-foot mark
should be dead center…if it is long by any measure, it’s either time to
replace the chain or it could already be too late.
I've seen chains that were a complete link (that's 1/2 inch) longer over the
entire length of chain compared to a new one...now how could that be a good
There’s nothing worse
than a chain that skips as you try to climb a hill or a loud rattle every time
you try to shift gears. These may
just be simple adjustment problems, but the neglected wear of a dirty, stretched
chain will definitely affect other components that will cost you unnecessary
grief and money before you know it. If
you keep your drive train clean, lubricated, and replace the chain regularly;
you’ll find you’ll have many miles of carefree cycling and you’ll avoid
those costly repairs due to excessive wear from an overused chain.
Come to think of it, I think I'll go change mine right now. Happy
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