How to Restring Clock Weights Safely

Cable-driven clocks rely on strong, smooth-running weight lines to keep accurate time and chime on schedule. Over time, these cables or strings wear out, fray, or break entirely. Knowing how to restring clock weights safely ensures smooth operation, protects the movement, and prevents damage to the case or pulleys.

Step 1: Understand the Clock Weight System

Weight-driven clocks power the movement using gravity. Each weight hangs from a cable or string that wraps around a drum or barrel, applying controlled tension.

Clock types that use weight lines include:

• Grandfather clocks (most 3-weight Hermle, Urgos, and Kieninger)
• Vienna regulators
• Wall clocks with side pulleys
• Some antique floor clocks with single-weight systems

These clocks use either:

• Steel cable (most modern German movements)
• Braided nylon or gut string (common in antique clocks and reproductions)

You must restring with the correct type and thickness to avoid slippage, stretching, or mechanical damage.

Step 2: Gather the Correct Parts and Tools

Before beginning, gather:

• Replacement clock cable or braided string (check movement specs)
• Clock pulleys (reuse or replace if damaged)
• Small flat screwdriver
• Needle-nose pliers
• Masking tape or cloth to protect the dial and hands
• A helper (for large clocks)

Measure the original string or cable’s:

• Length
• Diameter
• Material
• End fittings (loop, pin, stop, etc.)

Clockworks offers full restring kits that match most German-made cable-driven movements.

Step 3: Remove the Clock Movement Safely

Always disconnect power and stop the pendulum before handling weights or cables.

1. Open the clock case and remove the weights. Label each one (Left, Center, Right) to avoid mix-ups.
2. Remove the pendulum for safety.
3. Let the cables or strings unwind fully, using care to prevent backlash.
4. Remove the movement if needed for easier access. Set it on a clean, padded surface.

Do not try to restring with tension still on the drums—this can lead to serious injury or movement damage.

Step 4: Remove the Old Cables or Strings

1. Locate the cable drum or pulley spool for each weight line.
2. Detach the old cable or string from the drum. Most use set screws, anchor holes, or tie-offs.
3. Remove any stops, sleeves, or crimps from the ends.

Inspect the drum grooves and pulley wheels for wear. Replace any chipped, bent, or worn pulleys to avoid cutting the new string.

Step 5: Install the New Cable or String

1. Cut the replacement line to the required length—typically 7–8 feet for grandfather clocks, longer if the weights drop low.
2. Anchor one end of the string or cable to the drum. Use the same attachment method as the original (loop, hole, set screw, or knot).
3. Wrap the line onto the drum evenly and neatly, using the same winding direction as before.

Check that the drum rotates freely and the line feeds out smoothly. Avoid overlapping or crisscrossing lines on the drum—this causes jerky weight drop and misalignment.

Step 6: Set Up the Pulley and Weight

1. Feed the free end of the cable through the clock pulley.
2. Tie or crimp a secure loop or stop bead at the correct position to hang the weight.
3. Hang the weight from the loop or attached hook.
4. Repeat for each weight line, using correct side placements (L, C, R) if weights differ.

If you removed the movement, reinstall it carefully now, ensuring the lines feed through the case holes without binding.

Step 7: Test and Adjust

1. Slowly raise each weight to full height by gently rotating the drum or turning the crank key (if applicable).
2. Ensure the pulleys track straight and the cables don’t twist or bind.
3. Let the weights descend under natural operation and listen for smooth, even ticking.
4. Confirm that chimes and strikes activate correctly.

Make sure the weights stop just above the floor of the case when fully unwound—if not, shorten or lengthen the line slightly.

Safety Reminders

Always support the weights when cutting or tying cables.

Never rewind cables while the pendulum is swinging.

Avoid oiling the string or pulleys—this can cause slippage and early failure.

Use cable rated for the clock’s weight—thin string or fishing line won’t hold up.

Troubleshooting Tips

Cable slips or unspools:

• Re-check drum wrap direction
• Add a secure loop or anchor on the end
• Replace worn pulleys

Clock runs but weights don’t drop evenly:

• Weights may be hung in the wrong position
• Lines may be unevenly wrapped or too long
• One drum may not be turning (check chime train)

Weights jam or stop moving mid-week:

• Pulley may be catching on the case
• Crimp or loop may be too low
• Cables may be rubbing against each other

Common Mistakes to Avoid

Guessing cable size — Always match original diameter and material.

Using fishing line or wire rope — These fail under tension or cause uneven operation.

Forgetting to label the weights — Incorrect weight placement ruins chime and strike sync.

Skipping the pulley check — Damaged pulleys wear new lines prematurely.

Summary

Restringing clock weights safely takes careful planning, correct materials, and attention to pulley alignment. Whether you’re restoring a vintage cable-driven clock or replacing frayed weight lines in a modern movement, follow this guide to protect your clock and ensure smooth operation. For quality restringing supplies and expert help, visit Clockworks.com or email clockworks@clockworks.com—we’re here to help keep your weights moving and your clock ticking.

Updated on: 28/09/2025