The Shimano CN-HG93 [paid link] chain has long been praised for its smooth shifting and reliable performance. However, many riders experience a “skippy” feeling during pedaling, particularly under load. This can significantly affect ride quality and drivetrain longevity if not addressed promptly. In this guide, we’ll explore why your CN-HG93 [paid link] chain might feel skippy and how to eliminate the issue with precision and care.
Common Causes of a Skippy CN-HG93 [paid link] Chain
Chain skipping is not uncommon, even with high-quality chains like the CN-HG93. Several factors can contribute to this problem, and pinpointing the root cause is essential for a long-term fix.
Worn Chain or Cassette Teeth
One of the primary causes of chain skipping is wear, either on the chain itself or on the cassette teeth. Over time, the chain stretches microscopically, and the cassette’s teeth wear to match the shape of the chain. When a new chain is installed on a worn cassette, or vice versa, the mismatch leads to poor engagement and skipping under power.
The CN-HG93 chain is designed for compatibility with 9-speed drivetrains, but it requires careful attention to replacement cycles. Shimano recommends checking chain wear with a chain checker tool and replacing it once elongation reaches 0.75%. Ignoring this can lead to irreversible cassette damage, compounding the skipping issue.
Improper Chain Length
Chain length is critical for optimal drivetrain performance. A CN-HG93 chain that is too short will stress the drivetrain under load, leading to poor chain wrap and potential skipping. Conversely, a chain that is too long might slacken excessively, causing shifting imprecision.
To set the correct chain length for the CN-HG93, use the big-to-big method: wrap the chain around the largest front chainring and the largest rear cog without threading through the derailleur. Add two full links to this length before cutting. A precise length ensures that tension remains consistent across all gears.
Poor Drivetrain Cleanliness
Even the best chains will perform poorly if neglected. Dirt and grime buildup in the links or on the cassette can cause inconsistent engagement and chain skipping. The CN-HG93 features precision plates designed to mesh seamlessly with Shimano Hyperglide cassettes, but contamination can compromise this advantage.
Regular cleaning with a degreaser, followed by proper lubrication, is essential. Use a solvent-safe brush to scrub between the chain links and ensure no residues remain before relubrication. A clean chain maintains better contact with cassette teeth and reduces the risk of slipping under torque.
Misaligned Derailleur
A derailleur that’s out of alignment can prevent the chain from engaging fully with the cassette cog. This is particularly evident under load or when shifting into higher torque gears. The CN-HG93’s engineered dimensions demand a finely tuned derailleur hanger and properly adjusted limit screws for best results.
Check for a bent derailleur hanger and realign it if necessary using a derailleur alignment gauge. Fine-tune the cable tension and B-limit screw so that the pulley wheels are optimally positioned in relation to the cassette.
Step-by-Step Solutions to Fix Chain Skipping
Diagnosing and resolving a skipping CN-HG93 chain involves a methodical approach. Here’s a practical guide to address the problem:
1. Inspect for Wear
Begin by checking chain wear with a standard chain checker tool. If the chain stretch exceeds 0.75%, replace the chain. Next, inspect the cassette. Look for hooked or shark-tooth-like profiles on the cogs, a clear sign of wear. If worn, replacing the cassette is non-negotiable to restore proper chain engagement.
2. Verify Chain Length
Measure the chain using the big-to-big method mentioned earlier. If the chain is too short or long, replace it and cut the new CN-HG93 chain accurately. Incorrect length directly impacts tension and skipping.
3. Clean Thoroughly
Remove the chain and clean it using a degreaser. Let it dry completely before applying a suitable chain lubricant. Also clean the cassette and chainrings to ensure no debris interferes with engagement.
4. Adjust the Derailleur
Check derailleur hanger alignment and adjust it if necessary. Make sure the derailleur’s high and low limit screws are properly set. Adjust cable tension so that shifting is crisp and precise. Ensure the B-limit screw allows the top jockey wheel to maintain appropriate clearance from the cassette cogs.
5. Confirm Installation Quality
When reinstalling the chain, ensure the quick link or rivet pin is properly seated. An improperly installed quick link on the CN-HG93 can lead to inconsistent chain behavior and increase the risk of skipping.
Customization and Optimization Tips for the CN-HG93 Chain
Beyond simply fixing skipping issues, optimizing the CN-HG93 chain for longevity and performance ensures a better riding experience. Here’s how you can enhance its performance:
Routine Inspection
Check chain wear and drivetrain cleanliness at least once every 300 miles. Proactive maintenance helps prevent problems before they escalate.
Correct Lubrication Practices
Use a lubricant suited to your riding conditions—wet lube [paid link] for rainy, muddy conditions and dry lube [paid link] for dusty, dry environments. Always wipe off excess lubricant to avoid attracting dirt.
Gear Shifting Technique
Avoid cross-chaining by keeping a straight chain line as much as possible. Cross-chaining accelerates wear and increases the chance of the chain skipping, especially under load.
Replacement Timing
Don’t wait for the chain to cause problems before replacing it. Replace the CN-HG93 at regular intervals to preserve the integrity of your drivetrain components.
Conclusion
A skippy CN-HG93 chain is often the result of cumulative minor issues rather than one glaring fault. By systematically addressing chain wear, length, cleanliness, and derailleur alignment, you can eliminate skipping and ensure the CN-HG93 delivers the smooth, reliable performance it’s known for. Regular maintenance, proper installation, and a keen eye for early signs of wear are the best tools in maintaining drivetrain excellence.