How to Perfectly Adjust the Gear Shifter on Your Mountain Bike
To adjust the gear shifter on a mountain bike, first shift the bike to the highest and lowest gears to locate the limit screws on the rear derailleur. Use a screwdriver to adjust the limit screws to align the chain with the gears. Check if the chain moves smoothly by shifting through all the gears on the bike. If there are issues still, adjust the cable tension by unscrewing the cable securing bolt, altering the tension, and re-tightening the bolt.