Diamondback SHEPPARD CYCLES Owner's Manual page 75

sprocket, the chain will come off when pedalling. If the guide pulley is set
too far toward the larger cogs, the chain wheel may not shift onto
the small sprocket. Re-tighten the cable fixing bolt.
At this point the cable must be checked and adjusted to eliminate
slackness with the right shifter all the way to the low position
(fully forward for downtube shifters, fully back on MTB top bar shifters).
If there is too much slack, loosen the cable fixing bolt, pull the cable taut,
High Gear
and re-tighten the bolt.
adjustment screw
To adjust low gear, turn the adjustment screw marked 'L' far enough
counter-clockwise so that you can shift the chain onto the largest rear
LowGear adjustment screw
sprocket and the smallest chainring. Move the shifter until the derailleur
guide pulley and the sprocket are aligned. Turn the 'L' adjustment screw
Rear Derailleur Side View
SIS Cable Adjuster
until it meets resistance. If the screw is turned in too far it will allow the
derailleur to move outward and throw the chain off the sprocket when
pedalling. If the adjustment prevents the derailleur moving far enough,
the chain may not engage low gear.
Test the adjustment by shifting the chain rapidly up and down the
freewheel. On bicycles equipped with indexed gears (SIS) the chain
should move into each position without hesitation. If the chain won't
move easily onto the large sprocket while on the small chainring, screw
out the 'L' adjusting screw slightly. If the small sprocket is difficult to
engage with the chain on the large chainwheel, screw out the 'H'
adjusting screw slightly.
When adjusting SIS rear derailleurs there are some additional points to
attend. Some derailleur models have an additional adjustment screw to
set the guide pulley as close as possible to the sprocket. This is adjusted
with the chain on the small cog and when set there must be no hint of
rubbing noise or fouling when pedalling in reverse.
After a period of use, the derailleur cable will stretch and you may find
difficulty shifting the chain to the large freewheel cog or the large
chainwheel. If this occurs, re-adjust the cable either with the barrel
adjuster or by repeating the above procedures.
73
SC/2012
SHEPPARD CYCLES ABN 60 082 376 289