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Adjustment and replacement
On derailleur geared bicycles the rear derailleur automatically tensions the chain. To adjust
the chain on single speed freewheel, coaster hub braked or 3-speed hub geared bicycles:
1. Loosen the rear axle nuts (and coaster brake arm clip if fitted) and move the wheel
forward to loosen, or backward to tighten, in the frame.
2. When correctly adjusted, the chain should have approximately 10mm of vertical
movement when checked in the center between the chainwheel and rear sprocket.
Center the wheel in the frame and re-tighten the axle nuts after any adjustment.
Bicycles which have a single speed freewheel, coaster hub brake or 3-speed hub,
generally use a wider type chain than derailleur geared bicycles. These chains can
be disconnected by way of a special U-shape joining link, that can be pried off of the
master link with a screwdriver. To replace, feed the chain around the chainwheel and
rear sprocket, fit the master link into the rollers into each end of the chain, position
the master link side plate, and slip on the U-shaped snap-on plate. Make sure the open
end of the U-shaped plate is trailing as the link approaches the chainwheel when
pedaling forward.
Derailleur geared bicycles use narrower chains and require a special tool to fit and
remove chain links, or to change the length. To remove, fit the rivet tool so that the
punch pin is centered over any one of the chain rivets. Push the rivet almost all the
way out, then back out the punch and remove the tool. Holding the chain on both sides
of the punched rivet, bend it slightly to release link from the rivet. To install, feed chain
around chainwheel, rear sprocket and derailleur cage with rivet facing away from the
bicycle. Bring the two ends together within the chain rivet tool and punch the rivet into
place. Be sure not to push rivet too far through side plate (Fig. 4.12).
Freewheel
Like the chain, the freewheel must be kept clean and well lubricated. If the chain has
become worn and needs replacing, then it is likely that the freewheel will also have
become worn and should also be replaced. Take the chain off the freewheel and rotate
it with your hand. If you hear a grinding noise or the freewheel stops suddenly after
spinning it, it may need adjustment or replacement. Such action is beyond the scope
of this manual and you should consult a bicycle specialist (Fig. 4.13).
MAINTENANCE
Chain
rivet tool
Punch pin
4.12
4.13
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