Rear Derailleur Adjustment - Shimano Altus 7 Speed

Gear shifting problems - If your chain comes off when you switch to the granny chainring (i.e., largest rear cog) or your derailleur is consistently having problems keeping your chain on the correct cog then you may be able to fix the problem with a simple adjustment. On a Shimano Altus 7 speed rear derailleur, there is a knobby adjustment mechanism located at the point where the gear shifting cable enters the derailleur. The knobby adjustment mechanism can be seen in the subsequent picture by following the black cable (in the forefront of the picture) into the back of the derailleur. First, position yourself at the rear of your bike so you can see how well the rear derailleur is lining up with your cogs. Second, tweak the derailleur's alignment with the cogs by slowly twisting the knobby adjuster clockwise or counter-clockwise until the derailleur is placing your chain on the center of your cogs. Finally, test that the derailleur is centering the chain on each of the cogs by shifting through all of the gears. If this procedure does not solve the problem then your derailleur may be bent and, thus, it may require a more serious fix.