S1 Publishing(Oxford)© 1999-06

World of motorcycleS
S1 Publishing(Oxford)© 1999-06
Chains and Sprockets
Drive Chains, Adjustment;
As the main drive chain is used, the chain stretches, and becomes slack. To keep the chain to the correct tightness, the chain must be adjusted. This is easily done; Most chains should have about 2-3CM of play, an bit more for off road bikes.

Trials Type: See below
Model used, Honda XR400

Type 2: See below
Model used, Honda cb550/4k

Type3: Click on photo for more info.
Model used, Kawasaki ZXR400
(Video clip awaiting publishing)
First put the machine on the main stand, with the engine in neutral. Then remove the split pin (if fitted) in the rear spindle, and slackening off the nut. Then depending on the type of adjuster fitted you either move the adjuster to the next number indicated,as used on off road machine shown here
 In this photo you can see the 10 mark aligns with the pin in the swinging arm. To tighten the chain it would be turned clockwise on one or two notches, then anti clockwise on the opersite, the same amount of notches. If you this type of adjuster it's that easy. all you have to do is to tighten the nut again and turn the back wheel a few times to make sure the chain is not snagging or too tight.
First put the machine on the main stand, with the engine in neutral. Then remove the split pin (if fitted) in the rear spindle, and slackening off the king nut. 
slacken the two locking nuts (the most rearward of the two nuts on the adjuster), and then you do the adjuster bolt in (up) a half a turn on the left adjuster, then a half a turn on the right side of the adjuster, this keeps the rear wheel in alignment. 
 Repeat this until check if the chain. This you do by putting your finger on the lower part of the chain, which is usually accessible, roughly between the sprockets. If the chain is able to move up about 2', 5 cm (more is you have a moto-x/enduro machine), it is about right, if it moves further than that, it is still too slack, if it won't move, then the chain is too tight. If it is still too slack, turn the adjuster nut up again, a half a turn on the left, then the right.
Spin the wheel , look and listen for tight spots or any other sign of wear.
When the correct amount of adjustment is achieved, re-tighten the two locking nuts on the adjusters, then re-tighten the king nut on the spindle, and replace or renew the split pin.
If you have made the adjustment, and you have run out of numbers on the adjusters, then replace the chain, personally I replace my chains before they get that far.

Click on the Photo for a larger view
Allan Key Type
Again place the machine an a main stand, release the clamp bolts located at the end of the swinging arm, turn the key few degrees one side then the other side.
Chain Replacement; Split link type:
Put the machine on the main stand or pit stand, with the engine in neutral. Then remove the split pin and loosen the king nut, loosen locking nuts, and undo the adjuster nuts, until you are able to move the rear wheel forward as far as is possible. Then find the split link, and turn the wheel untill the split link gets to about o'clock (on a clock face), and then using a pair of pliers, remove the "fish" from the link, then remove the side plate from the link. 
Push the rear of the link out from the main part of the chain. 
 Then replace one of the pins into one of the links on the old chain, the other pin, place into the link on the new chain, pull the end of the old chain, this should feed the new chain over the front sprocket.
 If you have the new chain ready, put one end of the pin from the split link into one end of the new chain, and, the other pin into top link the old chain. Then pull the bottom of the old chain. This will feed the new chain through to the front sprocket, which avoids the need to remove any front casing and ancillary parts. 
Removing and replacing the Wheel (rear) sprocket
Wheel Sprocket As the machine is used, the sprocket suffers from normal wear, the teeth get a little less metal on them, the longer they get left, the more the damage the suffer. To check the teeth, place the machine on it's center stand with the engine in neutral, then turn the back wheel to see all of the teeth. Look for chips on the teeth, look for hooked teeth, or, even worse than than, look for teeth missing.
Replacement; Place the machine onto it's center stand, remove the split pin from the spindle on the rear wheel, and remove the king nut and washer. Then remove the back wheel from the swinging arm. place the wheel on the floor, with the sprocket upwards. Using a hammer and either a screwdriver, or a drift, knock the tab washers until they are flat. Then remove the nuts from the sprocket. Place the new sprocket into position (so the bolts come through the holes on the sprocket), Then replace the tab washers, replace the nuts. Then bend the tabs up, so that they stop the nuts from moving. Then replace the back wheel into the swinging arm then re grease and replace the spindle, washers, king nut and split pin. Before riding, check the chain adjustment, and make sure the rear brake is operating correctly.

A chipped tooth

These teeth now looks like a sharks fin, a sure sign that the sprocket needs replacing.
Engine Sprocket
to be done
This is just a general guide. If you are about to do your own maintenance, using these pages, I take no
                                responsibility if you get things wrong!