The Shimano CN-HG701 [paid link] chain is a popular choice among road cyclists due to its durability and performance across 11-speed drivetrains. However, even the best chains can exhibit skipping issues if not properly installed or maintained. Understanding the root causes behind a skippy chain and applying the correct solutions ensures a smoother, more efficient ride. Below, we will cover the technical reasons your CN-HG701 [paid link] chain might feel skippy and the exact steps to diagnose and resolve the problem effectively.
Understanding the CN-HG701 Chain
Before diving into troubleshooting, it’s important to grasp what makes the CN-HG701 [paid link] distinct. Designed for Shimano 11-speed road and mountain drivetrains, the CN-HG701 features:
- SIL-TEC coating for enhanced durability and reduced friction.
- Directional design to optimize shifting performance.
- Hollow pins to lower overall weight without compromising strength.
These features make it a premium option, but they also mean the chain demands precise installation and care to perform at its best.
Common Causes of a Skippy CN-HG701 Chain
Several factors could lead to a skipping sensation during pedaling or shifting. Recognizing these issues is the first step to a solution.
1. Incorrect Chain Length
An improperly sized chain is a frequent cause of skipping. If the chain is too long, it won’t maintain adequate tension, particularly in smaller cog combinations. Conversely, a chain that’s too short can strain the drivetrain under load.
2. Worn Cassette or Chainrings
Even a new CN-HG701 chain can skip if paired with worn cassette cogs or chainrings. As components wear, the teeth lose their shape and fail to engage the chain properly, resulting in slippage under torque.
3. Poor Installation
Directionality matters. Installing the chain backward can compromise shifting and lead to incomplete engagement with the cassette teeth, especially under load changes.
4. Stiff Chain Links
During installation, improper pin insertion or a neglected quick-link can cause a stiff link. This disrupts the natural flow of the chain across the cassette, leading to intermittent skips.
5. Incorrect Derailleur Adjustment
A misaligned rear derailleur or poorly tuned limit screws can fail to maintain chain tension and accurate cog alignment. This issue is particularly prevalent when shifting under load or on uneven surfaces.
6. Chain Wear and Stretch
Over time, the CN-HG701, like any chain, will elongate due to internal wear. “Chain stretch” leads to poor engagement with the cassette, resulting in jumps and skips even if the rest of the drivetrain is in good shape.
Diagnosing the Problem
Effective troubleshooting involves a methodical approach to pinpoint the exact cause of skipping.
Check Chain Length
Shift to the smallest chainring and the largest cassette cog, and check the derailleur’s position. A correctly sized chain will position the derailleur at an appropriate angle without excessive slack or tension.
Inspect the Cassette and Chainrings
Look for shark-fin-shaped teeth or any visible deformation. If noticeable wear is present, consider replacing the cassette or chainrings alongside the chain.
Verify Chain Direction
Shimano’s CN-HG701 features subtle markings indicating the outer and inner plates. Ensure the logo side faces outward to maintain intended shift performance.
Flex Chain Links
Manually bend the chain laterally at various points to detect any stiff links. A stiff link will resist lateral movement and should be loosened using a chain tool or replaced if necessary.
Confirm Rear Derailleur Adjustment
Shift through all gears while observing the derailleur. Ensure smooth transitions without hesitation or noise. Minor adjustments to the barrel adjuster can fine-tune indexing issues.
Measure Chain Wear
Using a chain checker tool, insert the tool into the chain. If it indicates more than 0.5% elongation, it’s time for replacement to prevent damage to the drivetrain.
Instant Improvements to Stop Skipping
Once the source of the issue is identified, you can implement the appropriate solution.
Resize or Replace the Chain
If the chain is incorrectly sized, remove links as needed or replace it entirely. Always follow Shimano’s sizing method: wrap the chain around the largest chainring and largest sprocket (without passing through the derailleur), add two full links, and cut accordingly.
Replace Worn Components
If inspection reveals significant wear on the cassette or chainrings, replace these parts alongside the chain. Pairing a new CN-HG701 with worn cogs results in accelerated wear and persistent skipping.
Properly Install the Chain
Ensure the chain is routed correctly and that directional markings are followed. Use Shimano’s quick-link or connecting pin with proper torque specifications to avoid stiff links.
Lubricate and Maintain
A dry or dirty chain can contribute to poor performance. Clean the chain thoroughly with a degreaser and lubricate with a high-quality chain lube, ensuring even coverage without over-application.
Fine-Tune Shifting
Adjust derailleur tension via the barrel adjuster for optimal gear indexing. If further issues persist, a comprehensive derailleur hanger alignment check may be necessary.
Preventing Future Skipping
Consistent maintenance and correct installation practices go a long way in preserving the performance of the CN-HG701 chain.
- Regular Inspection: Monthly checks for wear, tension, and lubrication help catch issues early.
- Timely Replacements: Replace the chain before it exceeds recommended elongation to extend cassette life.
- Correct Lubrication: Reapply lube every 200-300 kilometers or after wet rides to maintain smooth operation.
By adhering to these maintenance habits, riders can ensure that the CN-HG701 delivers the reliable performance Shimano designed it for, ride after ride.