how to install rear derailleur mountain bike

How to Install a Rear Derailleur on a Mountain Bike

Installing a rear derailleur on your mountain bike is an essential skill for any cyclist who wants to maintain or upgrade their bike’s shifting performance. Whether you are replacing a damaged derailleur or upgrading to a better model, this guide will walk you through the installation process step by step. Make sure you have the necessary tools and a bit of patience, as precision is key to achieving optimal performance.

Tools Required

Before you start, gather the following tools

- 5mm Allen key (or the appropriate size for your derailleur) - Phillips screwdriver - Chain tool (if you need to adjust or replace the chain) - Bike stand (optional but recommended) - Lubricant for chain and derailleur (optional)

Step 1 Prepare Your Bike

1. Secure Your Bike If you have a bike stand, place your bike in it. This makes it easier to work on. If not, flipping the bike upside down is an alternative, but be cautious about damaging the components. 2. Remove the Wheel To gain easy access to the derailleur, it’s often best to remove the rear wheel. Use your quick-release lever or a wrench depending on your bike’s setup.

Step 2 Remove the Old Derailleur

1. Loosen the Bolts Using your Allen key, loosen the bolts that secure the old derailleur to the derailleur hanger. Make sure to keep these bolts as you’ll need them for the new derailleur.

2. Disconnect the Chain If you’re replacing the derailleur, you might need to remove the chain from the derailleur. Use a chain tool to break the chain link or simply unthread it from the derailleur’s jockey wheels.

3. Take Off the Old Derailleur Once the bolts are loosened and the chain is disconnected, carefully twist and pull the old derailleur away from the hanger, making sure no wires or cables are caught.

1. Position the New Derailleur Take your new rear derailleur and position it onto the derailleur hanger. Ensure that it's facing the correct direction; the jockey wheels should be positioned under the chain line.

2. Secure the Derailleur Use the Allen key to tighten the bolts for the derailleur. Be careful not to overtighten as this could strip the threads or damage the derailleur.

3. Reconnect the Chain Thread the chain through the jockey wheels of the new derailleur. If your chain was split, now is the time to reconnect it using your chain tool. Ensure that the chain is properly threaded and sitting in the correct position.

Step 4 Adjust the Derailleur

1. Fine-tune the Limit Screws Use a Phillips screwdriver to adjust the high and low limit screws on the derailleur. These limit screws prevent the chain from shifting off the cassette or the derailleur. Shift to the smallest chainring and the smallest rear cog to set the high limit screw, and then to the largest chainring and largest rear cog to set the low limit screw.

2. Cable Tension Adjustment If your derailleur has a barrel adjuster, use it to adjust the cable tension. This ensures smooth shifting through your gears.

3. Test the Shifting With the rear wheel reinstalled, shift through all gears to ensure the derailleur shifts smoothly. If you experience any issues, revisit your limit screws and cable tension.

Step 5 Final Check

1. Inspect Everything Double-check that all bolts are tight, the chain is properly engaged, and the derailleur is functioning correctly.

2. Lubricate as Necessary Apply a little lubricant to the chain and the moving parts of the derailleur to ensure smooth operation.

Conclusion

Installing a rear derailleur on a mountain bike can seem daunting, but with the right tools and a step-by-step approach, it's a task that you can easily complete. Regular maintenance of your derailleur system will prolong its life and enhance your riding experience. By ensuring proper installation and adjustment, you’ll enjoy hassle-free shifting on your next mountain biking adventure. Happy riding!