The Shimano CN-HG71 [paid link] chain is a trusted component for many road cyclists due to its durability and precise engineering. However, even the most reliable chains can develop performance issues over time, and a “skippy” feeling during pedaling is one of the most common complaints. In this guide, we will explore the specific reasons why your CN-HG71 [paid link] chain might not be performing smoothly and provide detailed solutions to restore its efficiency.
Understanding the Causes of a Skippy Chain
A skipping chain often feels like an intermittent slip or jump, especially under load. While this issue might seem trivial at first, it can lead to significant drivetrain wear and decreased riding performance. With the CN-HG71 [paid link], the causes can usually be traced to a few key areas:
Chain Wear and Stretch
Chain stretch is a misnomer; the links don’t physically stretch but the pins and bushings wear down over time, increasing the chain’s overall length. A worn CN-HG71 chain will not seat properly on the cassette cogs, leading to that skippy sensation.
Worn Cassette or Chainrings
Chains and cassettes wear together. If you replace only the CN-HG71 chain without replacing a worn cassette or chainrings, the new chain may not mesh correctly with the old, worn teeth. This mismatch is a major source of skipping.
Poor Chain Lubrication and Contamination
The CN-HG71 relies on consistent, proper lubrication to maintain smooth interaction with the drivetrain. Dried-out lubricant, dirt, or grime between the links can cause resistance and prevent the chain from settling securely on the sprockets.
Improper Chain Length
If the CN-HG71 chain was not sized correctly during installation, it could be either too short or too long. A chain that is too tight can strain drivetrain components, while one that is too slack will struggle to maintain tension, increasing the likelihood of skipping.
Faulty Installation or Joining
Shimano’s CN-HG71 chain requires a precise connection using a Shimano-specific quick link or pin. Incorrect installation can cause stiff links or weak joints, both of which may manifest as skipping under load.
How to Diagnose the Issue
Before you begin replacing components, it’s crucial to accurately diagnose the root cause. Here’s a step-by-step guide to help you identify the problem:
- Check Chain Wear
Use a chain checker tool specifically calibrated for 8-speed chains like the CN-HG71. If the tool indicates wear beyond 0.75%, the chain needs replacement. - Inspect the Cassette and Chainrings
Look for hooked, shark-fin shaped teeth, which indicate wear. Run your finger across the teeth to check for sharpness and irregular profiles. - Evaluate Lubrication
Spin the cranks backwards and observe the chain’s movement. A noisy or gritty feeling suggests poor lubrication or contamination. - Measure Chain Length
Ensure the chain follows the recommended Shimano sizing method: big chainring to big cog, without routing through the derailleur, plus two links. - Inspect for Stiff Links
Flex the chain side-to-side to detect stiff or binding links. A single bad link can cause irregular skipping.
Solutions to Instantly Improve Chain Performance
Once you have diagnosed the underlying problem, these corrective measures can restore your CN-HG71 chain’s smoothness:
Replace the Chain if Necessary
If wear exceeds recommended limits, replacing the CN-HG71 is imperative. Always use a fresh Shimano connecting pin or a compatible quick link to ensure a reliable joint.
Replace Worn Cassette and Chainrings
If you detect substantial wear on the cassette or chainrings, replace them along with the chain. Using an old cassette with a new chain will almost always result in persistent skipping.
Clean and Lubricate the Chain Thoroughly
- Use a degreaser to clean the chain completely, removing all grime and old lubricant.
- Dry the chain thoroughly before applying a fresh layer of chain-specific lubricant.
- Wipe off excess lubricant to prevent dirt accumulation.
Proper maintenance should be performed regularly to prolong the life of the CN-HG71.
Check and Correct Chain Length
If the chain length is incorrect, it’s advisable to re-size it properly:
- Remove the chain.
- Follow the Shimano chain sizing method carefully.
- Reinstall the chain with the correct number of links.
Fix Stiff Links
If you detect stiff links:
- Flex the chain laterally at the stiff link to loosen it.
- If the stiffness persists, consider replacing the chain entirely to avoid further drivetrain damage.
Preventive Maintenance Tips for the CN-HG71
- Inspect the chain for wear every 500–700 kilometers.
- Clean and lubricate the chain after every wet or dirty ride.
- Avoid cross-chaining (extreme gear combinations) to reduce unnecessary stress.
- Use high-quality lubricants suitable for the riding conditions you frequently encounter.
When to Seek Professional Help
While basic maintenance and inspection can be done at home, if skipping persists after trying all corrective measures, it’s best to consult a professional mechanic. Persistent skipping could indicate deeper drivetrain alignment issues or component compatibility problems.
Conclusion
A skippy CN-HG71 chain can severely impact your riding experience, but with careful diagnosis and proper corrective actions, it’s often easy to fix. Routine maintenance, timely replacements, and careful installation are the best ways to ensure your Shimano CN-HG71 chain runs smoothly and efficiently for thousands of kilometers.