How to Adjust Shimano Deore Gears

There are two ways to calibrate Shimano Deore gears: the high and low limiter screws can be adjusted to restrict derailleur travel and the rear derailleur's barrel adjuster can be turned to change the cable tension. It only takes a few minutes, a small Phillips screwdriver and a bike stand to get your bike shifting crisp and clean. By watching the chain travel over the gears as you shift the bike, you can monitor the adjustment process to more accurately alter your Deore gears.

Things You'll Need

  • Bike stand
  • Phillips screwdriver
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Instructions

  1. Limiters

    • 1

      Place the bike in a bike stand. Locate two small chrome screws just above where your rear shifting cable enters the derailleur. The top screw should be marked with an "H" for the high gear limiter, the smallest gear on the back of the bike. The bottom screw will be marked with an "L" for the low gear limiter, the biggest gear on the back of the bike.

    • 2

      Shift the gears down by turning the pedals with your left hand as you push the button on the right-hand shift lever with your right hand. This will drop the chain to the smallest gear on the back of the bike. Use a Philips screwdriver to turn the high limiter screw counterclockwise one full turn if the chain stalls or fails to drop immediately onto the smallest gear. Continue to slowly twist the screw until the chain drops onto the gear.

    • 3

      Shift the bike up by pushing the shift lever all the way to the right while turning the pedals. Use a Philips screwdriver to turn the low limiter screw counterclockwise one full turn if the chain does not fully climb up the gears or fails to reach the biggest gear on the back of the bike. Continue to slowly turn the screw until the chain jumps up and stays on the biggest gear.

    Barrel Adjusters

    • 4

      Shift the bike back down to the smallest gear by pushing the button on the shift lever and turning the pedals. Watch the chain shift down.

    • 5

      Shift the bike one gear up by pushing the shift lever to the right one click with your fingers. Twist the rear barrel adjuster two turns counterclockwise with your fingers if the chain hesitates or will not rise. This will put tension on the cable and make the chain jump up to the next gear. Continue to slowly turn the rear barrel adjuster until the chain jumps to the next gear. The rear barrel adjuster is the black serrated knob on the back of the derailleur. It has a hole where the cable passes through.

    • 6

      Shift the bike down by pushing the button on the shift lever as you turn the pedals. Give the shifter button one click at a time. The chain should move down one gear with each click. Turn the barrel adjuster two turns clockwise to release tension on the cable if the bike is sluggish to shift or does not shift at all. This will allow the derailleur to lower, causing the chain to jump down to the next gear more crisply. Push the shift lever button once. Continue to slowly turn the front barrel adjuster until the chain moves smoothly down through the gears, one click for each gear. The front barrel adjuster is the serrated knob where the cable enters the shift lever handle on the handlebars. It has a hole where the cable passes through.

    • 7

      Shift the bike through the entire gear range as you turn the pedals by hand. Note any hesitation and repeat the above steps when necessary until the bike shifts crisp and clean through the gear range.