Rear Derailleur Adjustment

These instructions should solve all shifting issues,motion by the rear derailleur past the biggest &
however they may be overkill for most users. Mostsmallest cogs to minimize the probability of problems
new bikes come with straight rear derailleur hangers,occuring. These instructions are for a single chainring
properly adjusted b screw, and properly set H &drivetrain. Our procedure ( algorithm ) is very quick
L screws. Hence stage#1-#3 are not required for forand proper for our bicycles, but allows for some
most new bike owners. However going through allvariability. Do not use these instructions for a multi
the steps should solve shifting issues if simply goingchainring bike. Step #1 Check the rear derailleur. View
through #4 is not sufficient. Stage #1 Make sure thethe H & L screws Step #2 H screw has a
rear derailleur hanger is straight Check the rearyellow oval around it. L screw has a blue oval.. Note
derailleur hanger. Visually, one can see the belowthe H screw is out & L screw is in. Step #3
hanger is bent inward toward the frame. A rearPlace the chain on the largest cog. Pull the cable with
derailleur hanger alignment tool is required to adjust ityour hand to create tension, if this causes the
perfectly. However when a tool is not available it canderailleur to move inside the largest cog you must
be adjusted by pulling the derailleur with ones handturn the L screw clockwise until the derailleur is below
away from the cassette until the derailleur isthe biggest cog, then back off counterclockwise a bit
perpendicular to the ground. The stock hanger is very( not to restrict range ). This will keep the rear
soft and can be bent several times. Below we usederailleur from coming off the largest cog &
the Park DAG-1 too to straighten the hanger. We willbacking off will not restrict the range of motion. Step
remove the derailleur, then use the tool to check if it#4 Place the chain in the smallest cog. Relieve all
aligned properly, if it is misaligned we will use the tooltension from the cable, if this causes the derailleur to
to bend it back into place and repeat until we aremove outside the smallest cog you must turn the H
finished. From geometry we know two points definescrew clockwise until the derailleur is below the
a line, and three points define a plane. Our goal is tosmallest cog, then back off counterclockwise a bit (
place the hanger on a parallel plane with respect tonot to restrict range ). This will keep the rear
the cassette. We will use the tool to place thederailleur from coming off the smallest cog &
hanger on a parallel plane as the rim. We will assumebacking off will not restrict the range of motion.
the rim and cassette are on parallel planes. We willStage #4 Cable tension adjustment We will assume
use the DAG-1 tool to measure the distance fromyou have gone through stages #1 to #3 in adjusting
the rim at 3 different points and to bend the hangera rear derailleur. This is the last and possibly easiest
until the distance from three points to the rim is thestep. You will require a bike stand or a person willing
same. Step #1 Remove rear derailleur from theto hold the rear wheel in the air. Due to spring
hanger with an allen wrench. Step #2 Install thetension the rear derailleur prefers to stay in the
DAG-1 hanger tool onto the hanger as shown Stepsmallest cog ( assuming there is no cable tension ).
#3 Test the distance from the DAG-1 tool to the rimCable tension lifts the derailleur into the larger cogs.
at three points. If this distance is the same theHence if the derailleur does not move into larger cogs
hanger is in the proper plane and the job is done.it needs more cable tension, achieved by turning the
Step #4 If the distances are not the same at allbarrel adjuster counter clockwise. If the derailleur
points around the rim use the tool as a lever bendingdoes not move into smaller cogs it has too much
the hanger to make the distances closer. Repeat thecable tension, and the tension must be relieved by
steps #3 & #4 as often as needed until theturning the barrel adjuster clockwise. In short our
distances are the same. Stage #2 Adjust the bprocedure ( or algorithm ) for adjusting the shifter is
Screw We will assume the rear derailleur H & Las follows. If the shifter is in a smaller number gear
screws are pulled out. Hence there should be nothan the chain ( for ex. chain is in #2 cog while shifter
restriction on the derailleur's movement. The b screwin #1 ) one should turn the barrel adjuster clockwise.
adjustment is required when either: A). In the largestOn the other hand. If the shifter is in a larger number
cog there is an issue with chainsuck ( when the chaingear than the chain ( for ex. chain is in #2 cog while
wraps around the largest cog instead of goingshifter in #3 ) one should turn the barrel adjuster
directly to the rear derailleur). B). One experiencescounterclockwise. Step #1 View the barrel adjuster
shifting issues in the smallest cogs. As a general ruleon the rear derailleur. Step #2 Put the bike in a stand
of thumb the b screw should be about 6mm awayor have a partner hold up the rear wheel. Step #3
from the largest cog. Step #1 If you experiencePut the shifter in 1st gear and rotate the pedals. If
chainsuck issues in the biggest cog turn the b-screwthe chain is not in the biggest cog we will assume it is
clockwise to pull the rear derailleur back. Step #2 Ifin a smaller cog due to the limiting ( H & L )
you have problems shifting in the smallest cogs turnscrews do not allow it anywhere else. Turn the barrel
the b screw counterclockwise to push the rearadjuster counterclockwise & rotate the pedals
derailleur in. Stage #3 H & L screw adjustment Huntil the chain is in the largest cog. Step #4 Run
& L screws limit movement on the rearthrough the gears on the shifter from 1 to 9 if the
derailleur. The rear derailleur should never be allowedrear derailleur does not shift properly follow the
to move inside the inside face of largest cog, thisprocedure above Step #5 Run back through the
risks the chain getting caught between the spokesgears on the shifter from #9 to #1 if the rear
and rear cog. Once this happens you may need toderailleur does not shift properly follow the procedure
rebuild your rear wheel. Additionally the rear derailleurabove Step #6 Test shifting through the gears
should never be allowed past the outside face of theseveral times to make sure it is proper. One can
smallest cog. This could allow the chain to getadjust the derailleur while riding by turning the barrel
wedged between the frame & cog possiblyadjuster on the shifter clockwise or counterclockwise
tearing up the frame. The H and L screws will limit( as explained in the procedure ).