Shop Tech By: Brew Dude
This month’s tech article is on
chains. Chains?? Probably the
most neglected part of your bike is
the chain. They need adjusted,
cleaned and lubricated to function
correctly. I prefer chains over a
belt because I can play with the final
gearing to perform better by changing
either the front or rear sprocket or both
resulting in a different final gear ratio.
Also, if I have a problem with a chain on
the road, a chain can be changed quicker
and easier than a belt!
Most chain companies recommend chain
replacement when chains become stretched
1-1/2% for non o-ring and 1% for o-ring
chains. 20 links of 530 chain measures 12-
1/2″. If it measures more than 12-11/16ths
it needs to be replaced. When chains get
worn and need replacing, do you have any
idea what size, quality and how many
links? How many links is easy, count the
rollers or pins to get your number. An easy
way is to start at the connecting link or get
some white liquid paper and mark a link
you will start counting from.
Different motorcycles use different size chains
based on their engine horsepower and torque.
You’ll find 420, 428, 520, 525, 530 and 630 sizes
in most catalogs. What do these numbers mean?
The first number is the distance between links
measured in 1/8″ increments. A 4 means
4/8″ is 1/2″, 5 is 5/8″ and a 6 is 6/8″ or 3/4″.
Now you know if the first number is a 4, 5 or 6.
The next 2 numbers is the width of the chain at
the roller. This measurement again is measured in
1/8″ (.125″) increments. So a 20 is 20 x
125″=.250″ (1/4″). A 25 as the last 2 is 25 x
.125″ =.3125″ (5/16″) and a 30 is 30 x
.125″=.375″ (3/8″). So now you should know the
size and how many links.
Now comes the quality part of this article.
This is the hardest part because chains will have
different thicknesses of side plates, different
diameter of link pins and also different types of
heat treating and steel alloys. The chain
companies will have tensile strengths and some
also have a life table listed in their catalog or on
their Web site. The chain companies also have
recommendations determined by engine size or
horsepower.
Because of the different thickness of side
plates and o-ring chains, the overall widths
of chains differ greatly. The greater width
can cause many clearance problems.
These clearance problems can cause engine
case destruction, paint worn off the fender
or frame, rubbing the side of the tire and
frames with gouged tubes. Check your
clearances before there is a problem. (See
pics top of next column)
Now I could go on and on about sizes
but this is available on Web sites or has
been written before in books and
magazines.
BUT, one important fact about chains to
know is the connecting link also
referred to by some companies as
the master link. Some chains use
links that have to be pressed on. This type
requires a special tool. Don’t try to do this yourself unless
you purchase a quality tool and press the
chain on correctly. Look at the picture and
see the right way to press on the chain.
Now, if the chain has a master link with a
spring link clip make sure you install it so
the link clip has the closed end facing the
direction of the chain travel. (See
illustration.)
It amazes me how many clips are installed
the wrong way. If the clip is installed
backwards and it comes in contact with
anything, it may become unclipped,
causing it to fall off and soon the link follows
and then the chain!
Because of the different sizes of chains,
different overall width of links, pin sizes of
different diameters and different types of
installation there are many master links available.
If you have trouble on the road and need a
master link, a shop may not have one that
correctly fits your chain. Don’t try to install one
that has a different pin diameter or width or the
chain may come apart causing damage to the bike
or even cause personal injury. So, buy an extra
master link and put it in your tool bag or fasten
somewhere on the bike. Very cheap
insurance if you happen to have a chain
problem. This way you can fix your chain
and enjoy your ride.
