Shimano Deore shifters are known for their ease of use, strength, accuracy and dependability. The shifters' flat ergonomic design makes them simple to use for even the newest riders; however, they won't work correctly if they are not set up and adjusted properly. The bicycle will shift erratically and uncontrollably, leading to a frustrating bicycling experience. Adjust your Deore shifters at home to make your bike ride more enjoyable.
Set the bicycle in a work stand if you have one available. If you don't, set the bike on its kickstand while you work so it will not fall over.
Use a hex wrench to loosen the cable stop bolt on the rear derailleur and the front derailleur to loosen the cables. Set the barrel adjuster on each shifter to its original position against the lever body by turning the adjusters clockwise with your fingers.
Use pliers or cable grips to hold the cable of the rear derailleur taught while you tighten the rear derailleur cable stop. Be sure the cable doesn't slip through the cable stop bolt.
Pull the front derailleur cable taught in the same way as the rear. Tighten the front derailleur cable stop.
Take the bicycle out for a short test ride. Shift both shifters through every gear to ensure that they are working correctly. If a shifter is too tight (shifts more than one gear at a time or won't reach the highest gears on the cassette) loosen the cable slightly by loosening and re-tightening the cable stop. If a shifter feels too loose, tighten the barrel adjuster at the lever body to tighten the cable.