how to install a mountain bike rear derailleur

How to Install a Mountain Bike Rear Derailleur A Step-by-Step Guide

Installing a rear derailleur on your mountain bike is a crucial skill for any cyclist looking to maintain or enhance their bike's performance. Whether you're upgrading your drivetrain or replacing a worn-out derailleur, this guide will walk you through the installation process step-by-step, ensuring a smooth and efficient ride.

Tools and Materials Required

Before you begin, gather the necessary tools and materials

- New rear derailleur - Chain tool - 5mm Allen key - Screwdriver (flathead or Phillips) - Bike grease - Torque wrench (optional) - Bike stand (optional but helpful)

Step 1 Prepare Your Work Area

Find a clean and well-lit workspace to work on your mountain bike. If you have a bike stand, this will make the process easier, as it stabilizes the bike while you work. Ensure that the bike is shifted into the smallest rear cog to relieve tension on the derailleur and chain.

Step 2 Remove the Old Derailleur

1. Disconnect the Chain Use a chain tool to break the chain if it's not a quick-link chain. Alternatively, you can simply unthread it from the derailleur. 2. Loosen the Derailleur Locate the bolt securing the derailleur to the derailleur hanger, typically found at the rear dropout. Using a 5mm Allen key, loosen but do not completely remove the bolt yet. 3. Detach the Derailleur Once the bolt is loose, carefully remove the derailleur from the hanger. Also, disconnect any cable housing and the derailleur cable. If it’s stuck, a little gentle wiggle can help.

1. Position the New Derailleur Align your new rear derailleur with the derailleur hanger. It should fit snugly without forcing it. 2. Secure the Derailleur Insert the bolt and tighten it using the 5mm Allen key. If you have a torque wrench, refer to the manufacturer’s specifications for the correct torque setting. Ensure it's snug but not overly tight to avoid damaging the hanger. 3. Attach the Cable Thread the shifting cable through the cable guide on the derailleur. Use the appropriate screwdriver to secure the cable in place, ensuring it is taut enough to provide proper shifting without being overly tight.

Step 4 Reinstall the Chain

If you removed your chain, it’s time to put it back on. Here’s how to do it

1. Thread the Chain Start threading the chain through the jockey wheels on the new derailleur. Ensure the chain is routed correctly according to the derailleur’s direction of movement. 2. Connect the Chain If you broke the chain earlier, use the chain tool to connect it again or use the quick link if applicable.

Step 5 Adjust the Derailleur

Before you take your bike for a ride, you'll need to adjust the derailleur for optimal performance

1. Limit Screws Locate the high and low limit screws on the derailleur. These control how far the derailleur can move. Adjust them so that the derailleur can successfully shift between the smallest and largest cogs without overshooting. 2. B-Tension Screw Adjust the B-tension screw to ensure the derailleur has the correct gap above the largest cog. This gap is usually around 5-6mm, but check the manufacturer’s specifications. 3. Test Shifting Shift through all the gears while holding the rear wheel off the ground. Ensure that the shifts are smooth, and make minor adjustments as necessary.

Step 6 Final Check and Ride

Before you take your bike out for a ride, double-check all connections, bolts, and adjustments. Make sure everything is secure and properly aligned.

After your final checks, it's time for a test ride! Pay attention to the shifting performance. If you notice any issues, recheck your adjustments.

Conclusion

Installing a mountain bike rear derailleur can seem daunting, but with the right tools and a methodical approach, you can do it yourself. Following this guide will not only save you money but also increase your understanding of your bike, making future maintenance easier. Happy cycling!