Noisy shifting can turn even the most enjoyable ride into a frustrating experience. If you are running a Shimano CN-HG701 [paid link] chain and hearing unwanted sounds when shifting, it’s critical to understand the possible causes and how to correct them. This guide provides a comprehensive, technical approach to diagnosing and resolving noisy shifting, ensuring that your drivetrain performs with the smoothness Shimano engineered into the CN-HG701 [paid link] chain.
Understanding the CN-HG701 [paid link] Chain
The Shimano CN-HG701 chain is a premium 11-speed option, part of the HG-EV lineup, optimized for road and gravel riding. Featuring an asymmetrical plate design, SIL-TEC coating for reduced friction, and enhanced durability, it is designed to deliver precise, reliable shifting performance. However, improper installation, maintenance, or wear can lead to noise issues that compromise its functionality.
Common Causes of Noisy Shifting
Multiple factors can cause shifting noise when using the CN-HG701 chain. Understanding each potential cause is essential for accurate diagnosis.
1. Incorrect Chain Length
Chain length directly influences drivetrain tension and shifting performance. A chain that is too short can overstress components, while a chain that is too long may result in slack, causing delayed or noisy shifts. Shimano recommends setting chain length using the large chainring and large cog method, adding two links for proper tension.
2. Worn Chain or Cassette
Chains and cassettes wear in tandem. As the CN-HG701 chain stretches over time, it no longer meshes perfectly with the cassette teeth, leading to noise under load, especially when shifting under power. Regular measurement of chain elongation with a chain checker tool is necessary to prevent excessive wear.
3. Improper Installation Direction
The CN-HG701 is directional. The side with the laser-etched logos must face outward. Installing the chain incorrectly compromises the shift gates’ function, causing poor engagement and noise during shifts.
4. Dirty or Inadequately Lubricated Chain
Contamination and lack of lubrication are significant contributors to drivetrain noise. The SIL-TEC coating improves dirt resistance, but neglecting regular cleaning and lubrication reduces its effectiveness. A grimy chain increases friction and impairs shift performance.
5. Rear Derailleur Adjustment
A poorly adjusted rear derailleur — especially in the high and low limit screws or indexing — will cause the chain to hover awkwardly between cogs. Cable tension, B-tension screw positioning, and derailleur hanger alignment must all be correctly set to optimize shifting precision.
6. Chainring and Cassette Compatibility
While the CN-HG701 is versatile, using it with incompatible chainrings or cassettes (such as older 10-speed systems or non-Shimano components without the correct profile) can introduce shifting issues and noise.
Diagnosing Noisy Shifting with the CN-HG701 Chain
A methodical approach ensures no potential problem is overlooked.
Visual Inspection
Begin by inspecting the chain for visible wear indicators such as elongation, stiff links, or corrosion. Examine the cassette and chainrings for shark-tooth profiles or hooked teeth, common signs of wear.
Chain Length Verification
Shift to the largest chainring and the largest cassette cog without threading the chain through the rear derailleur. Pull the chain tight and check the overlap. Proper length shows minimal overlap beyond two full links when relaxed.
Check Chain Direction
Ensure the logos on the CN-HG701 face outward. If not, the chain must be removed and reinstalled correctly, as improper direction disrupts Shimano’s intended shift pattern.
Lubrication and Cleaning
Degrease the chain with a suitable solvent, rinse thoroughly, and dry. Reapply a high-quality chain lube, ensuring complete penetration into the rollers, then wipe off the excess.
Rear Derailleur Assessment
Check cable tension: with the bike in the smallest cog, shifting should produce crisp, audible clicks with no delay. If noise occurs during upshifts or downshifts, adjust barrel tension incrementally.
Evaluate the B-tension screw by ensuring adequate gap between the upper jockey wheel and the largest cog—around 5-6mm is ideal for Shimano 11-speed drivetrains.
Finally, check the derailleur hanger alignment with a gauge tool. Misalignment of even a few millimeters can induce noisy, imprecise shifting.
Fixing the Noisy Shifting
Once diagnosis is complete, apply the appropriate solution.
Adjust Chain Length
If the chain is too long, use a chain breaker tool to remove excess links. For chains too short, replacement is the only viable solution, as adding links compromises chain integrity.
Replace Worn Components
If chain stretch exceeds 0.5% or cassette teeth are visibly worn, replace the chain and cassette simultaneously to ensure matched wear patterns and optimal performance.
Correct Chain Installation
Reinstall the CN-HG701 with the correct orientation. Always use a Shimano-approved quick link (SM-CN900-11) or pin, torqued to specification.
Lubricate Correctly
After deep cleaning, re-lube the chain and allow it to settle before riding. Dry lubes are ideal for dusty conditions, while wet lubes are better for wet environments.
Fine-Tune Derailleur Settings
Use precise adjustments to cable tension and limit screws. Shimano’s tech documentation suggests minor 1/8th-turn adjustments to the barrel adjuster for precise indexing.
If derailleur hanger alignment issues are found, realign using a hanger tool. This step is critical; even minor misalignment causes noise on one side of the cassette.
Preventive Tips for Future Smooth Shifting
- Measure chain wear monthly using a reliable chain checker.
- Clean and lubricate the chain every 200-300 kilometers or after riding in poor weather.
- Periodically check derailleur alignment, especially after crashes or transport.
- Ensure compatibility between all drivetrain components to avoid mismatch issues.
By understanding the specific design and requirements of the Shimano CN-HG701 chain, you can effectively diagnose and resolve noisy shifting issues. Regular maintenance and attention to detail ensure your drivetrain remains as smooth and silent as it was designed to be, maximizing both performance and lifespan.