The first step to adjusting the
rear derailleur is to stretch out
the rear derailleur wire by pre stretching the wire we
help make our adjustments hold true for a longer period time. Grab the wire and pull the wire hard. It is more important to stretch a new wire. With an old wire you might not feel any stretch. You can see by the indents on my fingers that I pulled the wire hard Next, thread in the barrel adjuster. This way it can be used later. loosen the anchor bolt with a wrench to release the wire Now to set the wire tension I like the pull the wire as tight
as I can with my fingers and then tighten the anchor bolt down to hold the wire in place. Next we need to set the limit screws To make the high limit adjustment we need to disconnect the wire. The wire tension would otherwise interfere with the adjustment. To remove wire tension push the derailleur into the easy gears with your finger. Tension should release and you should be able to pull the wire out of the cable stop. After disconnecting the wire tension we move onto high limit screw adjustment These two screws limit how far up and down the derailleur to move on
cassette. The high limit controls how far down the derailleur can come
to the high (hard) gears. The low limit controls how far the derailleur can shift up into the easiest gears These are important screws. The high limit keeps the chain from falling down on the frame and scratching it. The low limit keeps the chain from falling into the spokes. The chain falling into the spokes can damage a wheel or chain. if we screw the high limit in far enough it should make it so the chain will not
ride in the smallest ring (hardest gear) Now we make the adjustment to make the chain ride in the hardest gear. unthread the high limit screw a little bit at a time Eventually the chain will fall onto the hardest gear. Double check that the chain will easily fall onto the smallest ring This can be done by pushing the derailleur up into the easy gears. Then let go of the derailleur while pedaling The chain should fall into the small ring smoothly If the the chain gets hung up before falling Then unthread the high limit screw a bit and try again. The chain should fall into the hard ring easily If the screw is unthreaded too far, the chain will fall onto the frame If the chain falls to the frame, screw the high limit in a bit After setting the high limit screw we need to reattach the the wire Push the derailleur and chain into the easy gears again This releases the wire tension set the cable back into the guides Pedal, the chain should fall to the small ring If it will not fall, the wire is too tight and must be loosend Now fine tuning the wire tension The high limit shouldn’t need to be touched again. We already set the limit without wire tension interference so setting the derailleur for the steps up and down the cassette is all done using wire tension which can be done using the barrel adjuster Lets check the shifting… 1 shifter click, and the chain moved up 1 more click, and the chain didn’t move That means we need to tighten the wire with the barrel adjuster Then check the shifting again It still has trouble moving up the cassette It did go up after hesitating – we are on the right track! another 1/8 -1/4 turn barrel adjuster to tighten the wire more Try shifting again It had a little trouble going up, so I tighten the wire a bit more. If the wire was too tight, it would make the derailleur swing too much with each shifter click. the over shift can make the derailleur skip gears. If the wire is to tight The chain may also have trouble falling into the small rings (tight wire example) The chain hangs up before falling down So I loosen the wire a little bit Then check the shifting again Still just a small hang up so to make the chain fall easier, loosen the wire a little bit more Now the chain shifts down freely Double check it will shift back up the cassette The two screws on the derailleur are also important If the derailleur pulley is touching any of the cassette rings the B-Tension screw needs to be adjusted Threading in the B-Tension screw in pushes the derailleur out away from the cassette cogs This should stop any rubbing The last screw is the low limit adjustment this controls how far up the derailleur can move If the screw is unthreaded too far The chain can be over shifted into the spokes Make sure the low limit is threaded in as far as possible So the chain will go into the big ring, but not over shift into the spokes If the limit is unthreaded to far you’ll see that there’s some play in a derailleur (side to side) as the derailleur tries to over shift To get rid of the play (and chance of over shift) thread the low limit in Now the side to side play is gone Double check the shifting now we know the low limit is set correctly Thanks for watching!