Chain drive is used on more motorcycles than drive
shafts or belts. The drive system consisting of a chain and two sprockets is
lightweight, efficient, and allows for easy gearing changes.
cleaning and adjusting of the motorcycle's drive chain is one of the most
overlooked maintenance requirement on any motorcycle. Because it's a time
consuming, dirty task to clean, lube and adjust the chain riders tend to put it
With periodic maintenance and adjustment today's modern O- ring
chains have doubled the life time of use we get from the drive chain. Today's
chains are made of stronger materials but are still subjected to the same
conditions; stress from horsepower, weather, and road grit. The greatest factor
in prolonging the chain's life is periodic maintenance. It's usually the lack
of maintenance that shortens their life spans.
Drive chains are made up
of links, side plates, pins, bushings and rollers. It's the rollers which
engage the sprockets teeth.
Today with the use of the o-ring chain; chain
life has been extended tremendously. The o-ring seals in grease to lubricate
the rollers; they also prevent water and dirt from getting in. The latest
innovation is the x-ring chain; it is supposed to reduce drag while still
offering the same level of reliability as the conventional o-ring chain.
Those little rubber rings have solved one of the chain maker's biggest
headaches; the loss of lubricant. The load bearing pins and bushings that
enable a chain to bend over a sprocket have precious little oil to keep them
lubricated. With high centrifugal forces that occur when the chain turns around
the drive sprocket, it forces the lubricant out and of the chain. The only
reason for chain wear is the loss of lubricant. With the use of the O-ring this
enabled the chain to keep its oil inside and stay lubricated where it counts
for longer periods of time and service.
The lubricant in a modern
O-ring chain is not ordinary oil. It contains plenty of synthetic additives
that help it withstand the enormous loads that develop during first-gear.
Friction is not a significant issue; the lubricant's film strength is what
keeps the metal from touching and wearing. The moment the lubricant is not
there, wear escalates.
The chain ends are joined together by a master
link. The master link may be staked, which is the strongest and safest method.
A staked master link creates an
endless chain, which is seen on most modern sportbikes. The staked master link
requires special tools to install or remove it.
The other method is by
the use of a spring clip, which can be installed and removed with a pair of
pliers. Master links with spring clips should always be installed with the
closed end facing the direction of travel. The spring clip can easily be
dislodged if the open end comes in contact with anything that can get in its
Even the cheapest chain without O-rings will last a
very long time with proper care, meticulous adjustment and oiling at 350-500
mile intervals. Heavy gear oil applied with a brush is used by many racing
teams. This is a messy proposition and best only when the chain can be left to
drip away the excess; preferably overnight.
Most people spray on chain
lube, which is good as long as you wait the required 20 minutes to let the
solvents in the spray evaporate and leave the thicker lubricant on the chain,
rather than on of the tire's sidewall.
Chain grease isn't as efficient.
It cannot get into the tight clearances between the moving parts and the most
good it can ever do is keep the chain's side plates from rusting in the winter.
Chain oil's main enemy is high running
temperatures. The running temperature of a chain should not exceed 160 degrees
Fahrenheit (70 degrees Celsius). Above that, chain lubricant starts to thin and
the chances of it seeping out past the O-rings increase; eventually the film
Surprisingly an over tightened chain is far worse than
a loose one. Suspension movement increases chain tension and what is a fairly
tight chain at standstill, will become tighter as the swingarm arc's through
its apex. These added unnecessary shock loadings can exceed the chain's
strength capacity and the increased friction will raise the chain's temperature
The best way to check chain tension, the one used by many race
teams; is too ask two of your biggest friends to sit on the bike and compress
the rear suspension to the point where the wheel axel, swing-arm bearing bolt
and the front chain-sprocket centerline are all in line. That is the point of
maximum chain tension. Or you can compress the bike's rear end with a
ratcheting tie down. Free up and down movement at the middle of the chain's
bottom run should be about half an inch (13 mm) with the suspension compressed.
Your motorcycle's owner's manual will have the recommended amount of
chain free play to be measured midway on the bottom run. That free play
includes both up and down movement of the chain while the bike is sitting on
Of course, a loose chain is not good either. It will rub on
many static parts of the bike such as the swing arm rubber buffer and frame
spacers. Besides, with the chain's ability to saw through anything in its path,
the added friction will again raise temperatures.
The sprockets will
also suffer from a loose chain condition. A loose chain will "ride up" into the
higher and weaker areas of the sprocket teeth and slowly bend them into a
hooked shape. Proper tensioning as explained above is the remedy.
proper tensioning means a straight and true running rear wheel. A cocked rear
wheel will place uneven stress on the chain, making one side of it work harder
than the other.
A quick check can be made by sighting the chain's top
run, back to front. A badly misaligned rear wheel will show as a notable kink
in the chain's run line.
For more exact results you can pick two eight
foot (2.5 meters) straight-edged wood boards and place each on either side of
the bike, about 4" (100mm) above the ground. On a properly aligned wheel, the
edges should touch the rear tire sidewall and leave equal gaps on both sides of
the front tire. Adjust your chain tension adjuster accordingly.
teams use a compass with two, long sharpened points to compare the distance
between the swing arm bearing pivot and the rear wheel axel; a measuring tape
can be just as effective; simply measure the distance from the center of the
swingarm pivot to the center of the axel. It should be the same on both sides,
if not adjust the chain tension adjuster until both measurements are the same.
Even after all this straightening, it's worth checking, making sure
that the chain runs centered on the rear sprocket. A missing 1mm washer
somewhere may cause one side of the sprocket to make contact with the chain. If
after some mileage one side of the rear sprocket gets shiny near the teeth it
means that the front and rear sprockets are not properly aligned. A few shims
or washers behind the drive sprocket may be necessary.
have a few problems all of their own. The mud or sand that gets trapped between
the chain and sprocket works as a fine grinding paste, destroying chains in no
time. The "relieved teeth sprockets" that are available from aftermarket
suppliers will help a great deal in reducing chain wear and stretch by letting
the dirt out of the high-pressure area where the roller and sprocket teeth
Proper maintenance of a dirt bike's chain also means a good
hosing after the ride, first drying and only then oiling. By the time of your
next ride all the excess oil will have dripped away, reducing dust pick up to
Chains really don't stretch but as they do their job the
lubricant between the pins and bushings is burned off by heat, pressure, and
friction; lose enough of the chain's lubricant and rapid chain wear, takes
place. As the various parts of the chain rub against each other, wear develops
between the pins and rollers. With the wear, the chain elongates.
Sprockets, as a rule do not require any maintenance other than inspecting the
mounting bolts and cleaning. As the chain wears and elongates (stretches), or
if the chain is allowed too long in a slack condition, it will ride up on the
sprocket teeth, quickly wearing the teeth into sharp hooks.
the chain for wear is rather easy. If you have it off the bike checking its
length is one method. On the bike, pulling the chain off the rear sprocket is
another. If you have too much play or you've run out of adjustment it's time to
replace the chain. When replacing the chain, the sprockets should be replaced
at the same time.
Manufacturers use a series of
numbers: 420,428, 520, 530, and 630, followed by a series of letters to
designate type style and strength. With motorcycle drive chains the first
number will always be a 4, 5, or 6. These numbers correspond to the chains size
or physical dimensions.
Chains are measured in pitch. The pitch is the
center to center distance between any two adjacent pins. The first number is
the pitch measured in eighths. A 4 series chain measures 4/8 (1/2) inch between
pins. A 5 series chain is 5/8 inch between rollers and a 6 is 6/8 (3/4) inch.
530 EK heavy duty o-ring chain
The next digits represent the
nominal width of the chain between the inner plates or bushings measured in
eights. A common 530 chain would measure 5/8"from pin to pin and would be 3/8"
between the inner plates. These are nominal measurements; the actual dimensions
can vary a little from manufacturer to manufacturer. They can also vary between
chains of the same dimensions, but of a different grade or style made by the
same manufacturer. The letters after the numbers are the way the manufacturer
describes the special characteristics that particular chain may have.
Pitch is Pitch, a 530 chain from any manufacturer the pitch will always be the
same 5/8"; as well as the roller diameter. Chain width between the roller link
plates may vary slightly as well as the overall width. The plates themselves
may be thicker or thinner, pin lengths will probably be different and so on.
It's pretty clear that one manufacturer's master link may or may not
fit another manufacturer's chain. Using matched chain and links is the best way
to insure the fit is correct and it's the correct tensile strength. Remember a
chain is only as strong as its weakest link. Using the incorrect master link; a
5,000 lb master link in a 10,000 lb chain application can drive that old adage
home. Never mix chain pieces or manufacturers.
Always check your
owner's or service manual for recommended types of chain, or the chain
manufacture's recommendations before replacing your chain. It's ok to upgrade
your standard chain to a heavier duty or o-ring chain. You should never use a
lesser strength chain than is recommended. It can and will wear faster and
possibly stretch faster letting the chain saw away on parts of your motorcycle,
or worse break, leaving you a long walk home.
Ok you're all excited
about running out to the garage and cleaning, lubricating and setting the
tension on your chain; but just what do you use for a chain cleaner?
Most chain manufacturers recommend
kerosene, WD 40 works well and it's easier to handle and far more convenient to
use. Be careful what you use to cut the gunk off of the chain with; especially
if you have an o-ring chain. It won't help no matter what you use if it damages
Locate the master link in the chain, and mark it so you
will know where you begin and end. Spray the WD 40 on the inside or the lower
run of the chain as you rotate the rear wheel. You may want to use a plastic
bag to cover the wheel and rim or any other parts you don't want wetted down
with the WD 40. Use a rag to wipe off excess WD and dirt from the chain. Pass a
corner of the rag in-between the rollers and clean the inside of the side
plates and the rollers.
Do not use a wire brush of any kind to clean
the chain; they can damage the o-rings. Use more WD 40 on stubborn areas and
rub with a rag.
Once you have the chain nice and clean, make sure the
sprockets are clean too; there's no sense in letting the grit stuck on the
sprockets to contaminate the clean chain.
With chain and sprockets now
clean, take the bike out for a short 15 minute ride. This will help warm up the
chain. As soon as you get home spray or brush your chain lube on the inside of
the chain, (That's the part of the chain that wraps over the sprockets yes the
inside. Centrifugal force will push the lube into the chain as you ride). Let
it stand for a few minutes. Read the label on the can for the time it will take
for it to work its way into the chain. Do not run the engine or put the bike in
gear to apply the lube, raise the rear wheel off the ground or push the bike
forward or back to get access to the chain.
Then take a rag and remove
the excess lube, do not remove all of the lube, just the excess.
o-ring chains need to be lubricated, any of the chain lubes will work even
heavy gear oil will.
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