How to Install, Adjust, and Maintain the Shimano ST-4600 Shifters

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in 105, Shifters, Shimano

The Shimano ST-4600 [paid link] shifters are a part of Shimano’s 105 series, designed to deliver reliable performance for road cyclists looking for a balance of cost and performance. These shifters are ergonomically designed for comfort and easy shifting, offering smooth, precise gear changes. Whether you are installing the ST-4600 [paid link] shifters for the first time or maintaining them to ensure their longevity, this guide will walk you through the process step by step.

Tools Required

To install, adjust, and maintain the Shimano ST-4600 [paid link] shifters, you will need the following tools:

  • 2mm, 3mm, 4mm, and 5mm Allen wrenches [paid link]
  • Phillips screwdriver
  • Shimano cable cutter
  • Lubricant (for cables and pivots)
  • Torque wrench [paid link] (optional, for precision)
  • Shimano brake and shift cable
  • Cable housing (optional, if replacing)
  • Grease (for threaded components)
  • Tire levers (if disassembling wheels)

Installation of Shimano ST-4600 Shifters

Step 1: Prepare Your Bike

Before starting the installation process, ensure that your bike is clean and stable. Remove any existing shifters if necessary, and check that the handlebar is properly secured in the stem.

Step 2: Install the Shifters onto the Handlebars

Shimano ST-4600 shifters are designed to fit on standard road handlebars. Begin by sliding the shifters onto the handlebars, making sure that the shift levers are in the correct orientation for easy access during riding. Tighten the screws with a 5mm Allen wrench [paid link], securing the shifters in place but not overtightening them at this stage.

Step 3: Install the Brake and Shift Cables

The ST-4600 shifters use Shimano’s “optical gear display” design, which allows you to see your gear position. For smooth operation, ensure that you route the cables properly:

  • Brake cable: Insert the brake cable into the brake lever, ensuring that it passes through the correct housing.
  • Shift cable: Insert the shift cable into the shifter mechanism, making sure it is routed along the frame properly. Follow the natural curve of the handlebar and down tube to avoid kinks and friction points.

Use Shimano’s recommended cable length to ensure a tight fit but not too tight to restrict movement. Cut the cables to the appropriate length with the cable cutter, leaving enough slack for future adjustments.

Step 4: Attach the Front and Rear Derailleurs

With the cables in place, attach the front and rear derailleurs to their respective mounts. The front derailleur should be positioned just below the bottom bracket, and the rear derailleur should be attached to the derailleur hanger. Ensure that both derailleurs move freely along their pivots.

Step 5: Adjust the Cable Tension

Once the cables are installed, it’s time to adjust the tension:

  • Front derailleur: Shift through all the chainrings, adjusting the barrel adjuster until the front derailleur moves smoothly from one chainring to the next without rubbing.
  • Rear derailleur: Use the barrel adjuster on the rear shifter to fine-tune the rear derailleur’s movement. Make sure that the derailleur shifts easily through all the cogs on the cassette.

Step 6: Check Brake Functionality

Before tightening everything fully, check that the brake function is smooth. Pull the brake lever to make sure the pads contact the rim evenly and respond well to input.

Adjustment of Shimano ST-4600 Shifters

Once your Shimano ST-4600 shifters are installed, adjusting them for optimal performance is crucial. Proper adjustments ensure smooth and precise gear changes while minimizing wear and tear on your drivetrain.

Adjusting the Shifter Levers

The Shimano ST-4600 shifters feature an ergonomic design that provides an intuitive and comfortable shifting experience. If you find that the shifter levers feel too stiff or too loose, adjust the cable tension:

  • For lighter shifting: Loosen the barrel adjuster to decrease tension.
  • For stiffer shifting: Tighten the barrel adjuster to increase tension.

Fine-Tuning Front and Rear Derailleur Movements

Use the barrel adjusters to make micro-adjustments to the shifting. The front derailleur should align with the outer chainring and shift smoothly, while the rear derailleur should move without hesitation across the cassette.

Fine-Tuning the Optical Gear Display

If you notice that the optical gear display (the gear indicator window) isn’t showing the correct gear, it may need a slight adjustment. This can typically be fixed by adjusting the cable tension, as a loose cable may cause inaccuracies in the display.

Maintenance of Shimano ST-4600 Shifters

Regular maintenance will prolong the life of your Shimano ST-4600 shifters and ensure their performance remains at a high level [paid link]. Here’s a maintenance checklist to follow:

Clean the Shifters Regularly

Dirt and grime can accumulate on the shift levers, affecting their movement and longevity. Wipe down the shifters after every ride with a damp cloth. For deeper cleaning, use a mild degreaser to remove oil and debris from the levers.

Lubricate the Cables and Pivots

Lubrication is key to maintaining smooth shifting. Apply a light layer of lubricant to the shift cables, making sure that it doesn’t drip onto the brake pads. For the shifter mechanism itself, use a lubricant specifically designed for bike components, and apply it to the pivots.

Check Cable Tension Periodically

Over time, cable tension can loosen, leading to poor shifting performance. Regularly check the tension by shifting through gears and making sure the levers don’t feel overly stiff or loose. Adjust the tension as necessary to ensure smooth gear transitions.

Replace Worn Components

As your Shimano ST-4600 shifters age, components like the cables and housings will wear out. Replace them as needed to maintain performance. Additionally, check the condition of the shifter springs and mechanisms to ensure they are functioning properly.

Troubleshooting Common Set-Up Issues

Despite the excellent performance of the Shimano ST-4600, you may encounter a few common issues. Here’s how to troubleshoot and resolve them:

1. Shifter Feels Stiff

If the shifter feels stiff or unresponsive, this could be a sign that the cable tension is too tight, or there’s an issue with lubrication. Start by loosening the barrel adjuster slightly and reapplying lubricant to the cables.

2. Shifting Delays

If there’s a delay between pressing the shifter and the gear change, check the derailleur alignment. Misalignment of the front or rear derailleur can cause inconsistent shifting. Use a derailleur hanger alignment tool to straighten any misalignment.

3. Chain Drops Off the Cog

A chain drop off the rear cog can be caused by insufficient cable tension or worn-out derailleur pulleys. Check the cable tension and inspect the derailleur pulleys for wear. Replace if necessary.

4. Skipping Gears

If the chain skips over the gears on the cassette, the derailleur hanger may be bent, or the cassette itself may be worn out. Check the hanger alignment and inspect the cassette for wear.

Conclusion

The Shimano ST-4600 shifters are an excellent choice for road cyclists seeking a balance between performance and price. Proper installation, adjustment, and maintenance are key to ensuring smooth and reliable shifting. Follow this guide to install your ST-4600 shifters, make any necessary adjustments, and keep them in top shape for many miles to come.