Shimano’s ST-6700 [paid link] shifters, part of the 105 series, offer excellent performance for road cyclists looking to upgrade their drivetrain. These shifters deliver precise shifting and a comfortable, ergonomic design that enhances the overall cycling experience. Whether you are replacing an old set, installing new ones, or maintaining your current ST-6700 [paid link], this guide will cover everything you need to know to get the most out of your shifters.
Tools Required:
- Shimano ST-6700 [paid link] shifters
- Cable cutter
- 5mm Allen wrench [paid link]
- Screwdrivers (flathead and Phillips)
- Torque wrench [paid link]
- Chain checker tool
- Lubricant (for cables)
- Grease (for threads)
- Cable tension tool
- Bike stand [paid link] (optional, but helpful for maintenance)
Installation of Shimano ST-6700 Shifters
Step 1: Preparing the Bike
Before starting the installation, ensure your bike is securely mounted on a bike stand [paid link]. This will provide easy access to all components, allowing for a smoother installation process.
Step 2: Removing Old Shifters
If you are replacing old shifters, start by disconnecting the shift cables from the front and rear derailleurs. Use a 5mm Allen wrench [paid link] to remove the bolts that attach the shifters to the handlebars. Carefully slide the shifters off the handlebars.
Step 3: Installing the New Shimano ST-6700 Shifters
- Slide the new ST-6700 shifters onto the handlebars.
- Adjust the position of the shifters so that they are comfortable for your hand placement. Typically, this will be at the center or near the curve of the handlebars, but personal preference will dictate the exact position.
- Tighten the bolts with a torque wrench [paid link] to ensure proper installation. Refer to Shimano’s recommended torque specifications to avoid over-tightening.
Step 4: Installing the Shift Cables
- Begin by threading the shift cables through the shifters. Make sure the cables are running smoothly from the shifters to the derailleurs.
- Install the cables into the front and rear derailleurs.
- Secure the cables with the appropriate cable tension.
Adjusting the Shimano ST-6700 Shifters
Step 1: Adjusting Cable Tension
Once the shifters and cables are installed, you may need to adjust the cable tension to ensure precise shifting. Use a cable tension tool or the barrel adjuster on the shifters to fine-tune the tension.
- If the chain is not shifting smoothly, either too tight or too loose, adjust the tension slightly until you achieve smooth, accurate shifting.
- When adjusting, ensure that there is no slack in the cables, but also avoid over-tightening them, as this can cause sluggish shifts or wear on the components.
Step 2: Fine-Tuning the Front and Rear Derailleurs
To ensure optimal shifting, fine-tune the front and rear derailleurs by adjusting the limit screws. These screws control the range of motion of the derailleurs, preventing the chain from overshooting the cassette or chainrings.
- For the rear derailleur: Adjust the high and low limit screws to ensure smooth movement between the smallest and largest cogs.
- For the front derailleur: Set the high and low limit screws to avoid the chain overshooting the large or small chainrings.
Step 3: Testing the Shifters
Once the shifters are adjusted, test them by shifting through all the gears while pedaling. Ensure that each shift is crisp and smooth. If there are any issues, re-check the cable tension, limit screws, and derailleur alignment.
Maintaining Your Shimano ST-6700 Shifters
Step 1: Cleaning the Shifters
Keeping your Shimano ST-6700 shifters clean is crucial for maintaining their longevity and performance. Use a damp cloth to wipe down the shifters after each ride to remove dirt and grime. For a deeper clean, use a gentle degreaser and a soft brush.
Step 2: Lubricating the Cables
Lubricate the shift cables regularly to prevent them from becoming stiff or rusty. Apply a light layer of lubricant to the cables as they enter the shifters and along the length of the cables. This will help them move smoothly and prevent wear on the internal parts of the shifters.
Step 3: Regular Inspections
Periodically inspect the shifters for any signs of wear or damage. Check the cables, the shifter body, and the brake lever mechanism for issues such as cracks, rust, or loose components. Replacing worn parts early will help avoid more significant issues down the road.
Troubleshooting Common Issues with Shimano ST-6700 Shifters
Issue 1: Shifting Is Sluggish or Sticky
This is often caused by dirty or dry cables. Inspect and lubricate the cables regularly to ensure smooth shifting. Additionally, check that the shifter mechanisms themselves are clean and free of dirt.
Issue 2: Shifters Won’t Change Gears
If the shifters are unresponsive, check for any issues with cable tension. If the cables are too loose, the shifters will struggle to change gears. Adjust the cable tension using the barrel adjuster until the shifting is smooth again.
Issue 3: The Chain Drops Off the Chainrings
If the chain is dropping off, the front derailleur may not be properly adjusted. Check the limit screws on the derailleur to ensure they are correctly set, preventing the chain from overshooting the large or small chainring.
Conclusion
By following the steps outlined in this guide, you can ensure that your Shimano ST-6700 shifters are properly installed, adjusted, and maintained for the best performance. Regular maintenance and prompt troubleshooting will keep your gear shifts smooth and precise for years to come. Keep your shifters clean, lubricated, and properly adjusted to get the most out of your riding experience.