Installing a Shimano CN-HG71 [paid link] chain requires precise technique and attention to detail. While the CN-HG71 [paid link] is renowned for its durability and smooth operation, improper installation can compromise drivetrain efficiency and lifespan. In this guide, we’ll explore the most common installation mistakes specific to the CN-HG71 [paid link] and how to avoid them to keep your drivetrain running flawlessly.
Understanding the CN-HG71 Chain
The Shimano CN-HG71 is a 6/7/8-speed chain designed for road and mountain bikes. Engineered with Hyperglide technology, it ensures seamless gear transitions. Its durable construction makes it a reliable choice for riders seeking longevity and performance. However, to unlock its full potential, the chain must be installed correctly, adhering to manufacturer specifications.
Tools Required for Proper Installation
- Chain tool (for pin installation and link sizing)
- Shimano Quick Link or replacement connecting pin
- Chain wear checker
- Torque wrench [paid link] (optional but recommended for drivetrain assembly)
- Chain lubricant
- Clean cloth
Incorrect Chain Length Sizing
One of the most prevalent mistakes during CN-HG71 installation is misjudging the chain length. A chain that’s too long can cause poor shifting performance and chain slap, while a chain that’s too short can damage the drivetrain under load.
How to avoid it:
Wrap the chain around the largest chainring and largest cog without threading through the derailleur. Add two full links to that length before sizing. This ensures adequate chain growth for suspension compression and rear derailleur travel. Always double-check your measurement before cutting.
Improper Connection Method
The CN-HG71 chain allows two connecting methods: Shimano’s dedicated connecting pins or a Quick Link (SM-CN10). Using a standard pin from another chain model or forcing a connection without the proper tool can lead to weak links and premature failure.
How to avoid it:
Use Shimano’s replacement connecting pin, identifiable by its black coating, or a compatible Quick Link. If using a pin, ensure it’s inserted cleanly using a quality chain tool and snapped off flush. Misaligned pins can create stiff links, leading to poor shifting and chain skipping.
Skipping Chain Break-In Period
Some riders install the CN-HG71 and immediately subject it to full load without allowing components to settle. This can exacerbate micro-misalignments and lead to increased wear.
How to avoid it:
After installation, perform a gentle break-in period. Spin through all gears under moderate load for the first few rides. This allows the chain to seat properly onto the cassette and chainrings, ensuring smoother long-term performance.
Failure to Check for Factory Lubricant
Shimano chains, including the CN-HG71, come pre-lubricated with a high-quality, long-lasting factory grease. Removing this grease prematurely can expose the chain to contaminants and reduce its lifespan.
How to avoid it:
Do not degrease the chain before first use. Simply wipe off any excess outer grease to prevent dirt attraction but leave the factory lube intact. Proper lubrication during installation ensures optimal initial wear resistance and performance.
Incorrect Derailleur Alignment
Even a perfectly installed chain won’t perform well if the derailleur is misaligned. Incorrect derailleur hanger position can strain the chain, cause skipping, or accelerate wear on the CN-HG71.
How to avoid it:
Check derailleur hanger alignment with a proper gauge. Ensure the derailleur is directly aligned with the cassette. Adjust high and low limit screws to prevent the chain from overshooting gears, and fine-tune the barrel adjuster for precise indexing.
Over-Tensioning the Chain
Some mechanics attempt to achieve a “tighter” chain feeling by sizing it too short or adjusting the derailleur B-screw excessively. Over-tensioning can reduce suspension travel on mountain bikes and overstress drivetrain components.
How to avoid it:
Follow the standard chain sizing method and ensure the rear derailleur maintains a natural chain wrap. Leave appropriate slack for efficient gear transitions and drivetrain health.
Ignoring Chainline Compatibility
The CN-HG71 is designed for a standard chainline on 6/7/8-speed systems. Installing it on an incompatible drivetrain with improper chainline spacing can lead to inefficient pedaling and noise.
How to avoid it:
Ensure the crankset, bottom bracket, and cassette are designed for the same speed category. Maintain a straight chainline where possible to reduce wear and improve overall drivetrain performance.
Omitting Proper Lubrication Post-Installation
After installation and break-in, some riders neglect regular lubrication, assuming the factory grease will last indefinitely. This oversight invites corrosion and stiffness.
How to avoid it:
After the initial break-in, begin a routine lubrication schedule. Clean the chain lightly, apply a suitable lubricant, and wipe off excess to maintain smooth operation and extend the CN-HG71’s lifespan.
Conclusion
Installing the Shimano CN-HG71 chain demands precision and adherence to best practices. Avoiding common mistakes such as incorrect sizing, improper connection methods, skipping break-in, and neglecting lubrication will ensure optimal performance and drivetrain longevity. By respecting these technical nuances, cyclists can fully enjoy the reliability and smoothness the CN-HG71 chain is engineered to deliver.