Herschede Grandfather Clock Pulley Wear Rebushing Repair Guide

Herschede grandfather clock pulleys showing severe wear with quarter-inch slop in bushing holes create critical reliability problems where clicking sounds during operation, whining during winding, and eventual weight falls through case bottom reveal progressive bearing failure requiring professional rebushing rather than simple pulley replacement. When clockmakers encounter movements that won't stay running despite clean pivots and proper bushing work elsewhere, hear clicking from pulley area during weight descent, or discover pulleys worn so severely that arbor has substantial lateral play, the diagnostic challenge occurs because worn pulley bushings create intermittent binding and power loss that manifests as stopping problems appearing unrelated to obvious pulley condition particularly when movement itself shows minimal wear creating false impression that cleaning and minor adjustment should suffice. This critical service situation happens because Herschede two-weight movements use heavy weights approaching thirty pounds creating concentrated stress on pulley bearings where cable tension combined with repetitive rotation over decades wears bushing holes oval or enlarges them substantially while simultaneously wearing arbor pins creating compound problem requiring both bushing replacement and arbor replacement for proper correction. This guide covers complete Herschede pulley service from diagnosis through professional rebushing technique. You'll learn identifying severe pulley wear through audible clicking during operation and visual inspection revealing quarter-inch or more lateral play in arbor, understanding why worn pulleys prevent reliable operation despite otherwise clean movement, disassembling pulley by center-drilling arbor freeing pulley from stirrup without damaging components, rebushing pulley through boring worn hole creating parallel round opening then press-fitting new brass bushing reaming to proper arbor diameter, fabricating replacement arbor on lathe turning new steel rod to specifications, and reassembling pulley assembly with light peening securing arbor ends in stirrup preventing future loosening. The key to successful pulley repair is recognizing that drilling alone won't produce round parallel hole required for proper bushing fit where boring operation using lathe creates precision round opening essential for press-fit bushing installation while new arbor prevents recurrence of wear from using partially worn original arbor that would accelerate new bushing failure creating premature callback requiring repeated service.

Understanding Herschede Pulley Problems

Two-Weight Movement Architecture

Herschede manufactured grandfather clocks using several movement configurations. Two-weight models represent cost-saving design developed during World War One when resources were scarce. Patent US1250173A describes novel mechanism allowing full quarter chimes using only two weights rather than three-weight system requiring additional train and components. However, cost savings came with reliability compromises. Two-weight system concentrates all strike and chime functions on single train creating heavier loading and more complex mechanism prone to wear.

Two-weight Herschedes were offered with five, seven, or nine tubes. Five-tube version plays three-quarter Westminster chime then strikes hour without full chime creating distinctive operational pattern. Later versions with full quarter four-quarter chimes use patented mechanism coordinating multiple functions through single weight-driven train. Heavy strike weight approaching thirty pounds provides power for extensive chiming creating substantial stress on pulley bearings and cable system throughout decades of operation.

These movements earned reputation among clockmakers as cantankerous when wear develops. Excessive bearing stress from heavy weights combined with complex strike mechanism creates multiple potential failure points. Falling weights through case bottom aren't uncommon particularly in movements approaching or exceeding 100 years of age without adequate service. While Herschede made many excellent clocks, two-weight models require special attention to pulley condition as this represents primary wear point affecting overall reliability.

Why Pulleys Wear Severely

Pulley bearing wear results from combined cable tension and rotational stress. Weight hanging from pulley creates constant downward force. As weight descends, pulley rotates against arbor creating bearing friction. This combination of static load plus dynamic friction wears bushing hole progressively over years of operation. Thirty-pound weight creates substantially more bearing stress than lighter weights used in many grandfather clocks accelerating wear rate significantly.

Wear pattern is typically asymmetric. Bushing hole elongates in direction of cable pull rather than wearing uniformly. This creates oval hole rather than simply enlarged round hole. Oval hole allows arbor to shift position during operation creating variable friction and potential binding. Additionally, arbor itself wears from constant contact with bushing creating reduced diameter in contact area. This compound wear - bushing enlarging while arbor reduces - creates excessive play manifesting as clicking, binding, and eventual operational failure.

However, wear severity varies between installations. Clock operated continuously for century without service develops extreme wear. Clock operated intermittently or serviced periodically shows less severe degradation. Additionally, cable maintenance affects wear rate. Kinked or damaged cable creates uneven stress concentrating wear at specific points. Fresh supple cable distributes stress more evenly reducing peak loading that accelerates bearing failure. Assessing wear severity requires disassembly and careful inspection rather than assuming all old pulleys need service.

Symptoms of Severe Pulley Wear

Most obvious symptom is audible clicking during operation. As worn pulley rotates, arbor shifts within enlarged bushing hole creating intermittent contact producing clicking sound. Sound frequency matches pulley rotation rate. Heavy strike weight pulley typically produces louder more frequent clicking than lighter time weight pulley. However, both pulleys may show severe wear even when only one produces audible symptoms. Systematic inspection of both pulleys prevents overlooking silent but equally severe wear.

Whining during winding indicates friction from worn bearings. As crank turns winding arbor raising weight, pulley rotates against worn arbor creating friction that produces audible whine. Sound may come from pulley itself or from wooden crank handle pivot needing lubrication. Distinguish between these sources by applying oil to crank handle pivot. If whining persists, pulley wear is likely cause. However, some whining is normal during winding. Excessive loud whining increasing over time indicates progressive wear requiring attention.

Movement stopping despite apparently adequate condition elsewhere suggests power loss from pulley friction. Worn pulley with quarter-inch lateral play creates variable friction as arbor shifts within bushing hole. Some positions create minimal friction allowing operation. Other positions create binding stopping movement. This intermittent behavior creates frustrating diagnostic situation where movement runs briefly then stops unpredictably. Clockmaker may clean, adjust, and optimize entire movement only to discover stopping continues because pulley wear wasn't addressed creating continued power loss overwhelming improvements elsewhere.

Pulley Disassembly and Assessment

Removing Pulleys From Clock

Access pulleys by removing movement from case or working within case if space permits. Herschede movements typically mount on substantial seat board secured with screws or bolts. Document cable routing and pulley positioning before disassembly. Photograph installation from multiple angles showing exact cable path and pulley orientation. This documentation prevents confusion during reassembly ensuring proper reinstallation without trial-and-error experimentation risking cable damage or incorrect routing.

Remove weights carefully supporting cable preventing sudden release that damages components. Let down any residual power in springs or weights before pulley removal. Disconnect cables from pulleys noting attachment method. Some systems use hooks through pulley strap holes. Others use cable loops or specialized fittings. Preserve original cable attachment hardware preventing need to fabricate replacements. However, severely worn cables may require replacement creating opportunity to upgrade attachment method if original design proved problematic.

Remove pulley assemblies from mounting brackets or suspension points. Note mounting orientation and hardware configuration. Pulleys may mount using specific alignment preventing rotation or allowing controlled rotation depending on design. Incorrect remounting creates operational problems despite successful bushing work. Label pulleys clearly indicating time versus strike and which end faced which direction during installation. This prevents accidental reversal during reassembly creating incorrect cable routing or weight interference.

Separating Pulley Components

Traditional pulley construction uses stirrup - metal strap forming U-shape - with arbor passing through pulley bore and extending into stirrup ends. Arbor ends are peened spreading material creating mechanical lock preventing arbor from pulling through stirrup during operation. Disassembly requires removing this peened material freeing arbor for extraction. However, aggressive removal risks damaging stirrup requiring replacement or repair beyond simple bushing work scope.

Proper technique uses center drill creating pilot hole in arbor end. Drill size should be slightly smaller than arbor diameter preventing complete arbor destruction while removing enough material for freeing from stirrup. Progress carefully testing extraction after each drilling increment. When sufficient material is removed, arbor pulls free from stirrup and pulley separates into components. This preserves stirrup for reuse while completely freeing pulley for bushing work.

Inspect separated components carefully. Examine pulley bore under magnification noting wear pattern and severity. Measure bore diameter at multiple points determining whether wear is uniform or asymmetric. Oval bore requires more extensive boring restoring round shape. Inspect arbor noting wear areas and degree of diameter reduction. Severely worn arbor requires replacement. Marginally worn arbor may be reusable if wear is minimal and bushing provides adequate bearing surface. However, using worn arbor in new bushing accelerates wear creating premature failure making new arbor preferable for long-term reliability.

Measuring Wear Severity

Quantify wear through systematic measurement. Use precision calipers or micrometer measuring bore diameter at multiple orientations. Typical new bore diameter for Herschede pulley may be half inch or slightly larger. Quarter-inch additional slop indicates bore has enlarged to three-quarters inch representing substantial wear requiring correction. Document measurements providing baseline for bushing work and verification of final dimensions after rebushing.

Measure arbor diameter at multiple points along length. Unworn areas show original diameter. Worn contact areas show reduced diameter. Difference indicates material loss from years of bearing friction. Few thousandths wear may be acceptable depending on total clearance and bushing fit. However, substantial wear creating stepped or irregular arbor profile requires replacement. New arbor ensures uniform bearing surface preventing premature bushing wear from irregular contact pattern.

Assess stirrup condition examining holes where arbor ends mount. These holes may show elongation or wear from decades of stress. Minor wear is acceptable. Substantial elongation requires stirrup replacement or repair. Stirrup serves critical function retaining arbor under substantial weight loading. Compromised stirrup risks catastrophic failure allowing weight to fall potentially damaging case or creating safety hazard. Conservative approach replaces questionable stirrups rather than risking failure from marginally adequate components.

Professional Rebushing Technique

Boring Pulley for Bushing Installation

Proper bushing installation requires precision round parallel hole. Drilling alone won't achieve this. Drill bits wander creating non-round holes. Chuck pulley securely in lathe ensuring concentric mounting. Face off any irregular surface ensuring flat reference. Drill pilot hole using size appropriate for boring tool. Progress to boring operation using boring bar creating precision round hole with parallel walls and controlled diameter.

Boring removes all worn material leaving clean fresh metal for bushing press fit. Bore diameter should provide appropriate interference fit for bushing. Too large bore creates loose bushing risking rotation or migration. Too small bore prevents bushing installation or requires excessive force risking pulley damage. Typical interference fit provides few thousandths diameter difference creating secure mechanical retention without requiring adhesive or other secondary retention method.

However, achieving proper boring requires lathe skills and appropriate tooling. Inexperienced operator may create tapered hole, oversize bore, or irregular surface preventing proper bushing installation. For clockmakers without lathe experience, professional service is preferable. Specialist with proper equipment completes boring quickly and accurately ensuring optimal results. Cost of professional service is modest compared to value of proper repair preventing future problems from inadequate amateur work.

Installing and Finishing Bushing

Select bushing material appropriate for application. Brass provides traditional bearing surface with good wear characteristics. Delrin AF - plastic material with embedded lubricant - provides modern alternative reducing friction and potentially extending service life. Both materials work well. Choice depends on availability, personal preference, and specific application requirements. For authentic restoration, brass maintains original design intent. For maximum longevity, Delrin may offer advantages in specific situations.

Press bushing into prepared bore using arbor press or similar tool. Apply even pressure avoiding cocking or tilting that creates uneven seating. Bushing should seat fully flush with or slightly below pulley surface. Protruding bushing may interfere with adjacent components or create cosmetic issues. However, excessively deep seating reduces effective bearing length potentially compromising load capacity. Proper seating balances these considerations achieving optimal installation.

After bushing installation, drill and ream bore to final dimension accepting new arbor. Drilling creates approximate size. Reaming produces precision dimension with excellent surface finish and dimensional accuracy. Reamed hole provides optimal bearing surface minimizing friction while maintaining proper clearance for arbor rotation. However, reaming requires progressive approach using successively larger reamers approaching final dimension incrementally. Attempting to ream entire material removal in single operation produces rough surface and potential reamer damage. Patient progressive reaming produces superior results justifying additional effort.

Fabricating Replacement Arbor

New arbor is turned from steel rod using lathe. Select appropriate diameter stock providing modest material removal achieving final dimension. Excessive initial diameter wastes material and increases machining time. Insufficient initial diameter prevents achieving proper finished dimension. Chuck stock securely in lathe using appropriate gripping length preventing deflection during turning. Face end creating flat reference surface perpendicular to rotation axis.

Turn arbor to final diameter matching original specifications or adapting to reamed bushing dimension. Maintain uniform diameter throughout length ensuring consistent bearing contact. Slight taper or variation creates uneven wear concentrating stress at high spots accelerating bearing degradation. Use appropriate tooling and cutting technique producing smooth surface finish. Rough surface increases friction reducing efficiency and accelerating wear. However, mirror finish isn't necessary. Reasonable machined finish provides adequate bearing surface for clock application.

Arbor length must accommodate pulley width plus stirrup thickness on both ends plus modest material for peening securing assembly. Too short arbor prevents proper assembly or creates inadequate peening risking future loosening. Too long arbor creates protruding ends that may interfere with adjacent components or create cosmetic concerns. Measure carefully ensuring proper length before parting arbor from stock. Correcting length errors after separation requires additional setup and machining operations wasting time and risking dimensional errors from multiple handlings.

Reassembly and Installation

Peening Arbor in Stirrup

Position arbor through bushed pulley and stirrup holes. Ensure proper alignment with arbor ends extending equally beyond stirrup on both sides. Support assembly on solid surface or in fixture preventing shifting during peening. Use center punch or similar tool creating controlled deformation at arbor end. Light hammer blows progressively expand material creating mechanical retention.

Peening requires controlled technique. Excessive force damages stirrup or creates gross deformation appearing crude. Insufficient force creates inadequate retention risking arbor loosening during operation. Goal is creating modest material expansion sufficient for mechanical lock without creating bulbous or irregular end appearance. Few well-placed blows using appropriate tool size produces workmanlike result functionally adequate while maintaining acceptable appearance.

Test assembly after peening attempting to withdraw arbor from stirrup. Properly peened arbor resists removal requiring substantial force for extraction. Loose arbor indicates inadequate peening requiring additional work. However, don't confuse rotational freedom with axial looseness. Arbor should rotate freely within bushing while remaining axially fixed in stirrup. Binding rotation indicates bushing dimensional error. Loose axial retention indicates inadequate peening. Distinguish between these conditions ensuring both rotation and retention are correct before proceeding with installation.

Installing Rebushed Pulleys

Position pulleys in mounting brackets or suspension points matching original orientation documented during disassembly. Incorrect mounting creates cable routing problems or interference with adjacent components. Verify proper alignment before securing mounting hardware. Pulleys should hang freely without binding against brackets or case structure. Any interference creates friction robbing power and potentially causing premature wear at interference points.

Route cables through pulleys following documented original path. Maintain proper cable alignment preventing rubbing against pulley edges or other components. Cable should run smoothly from winding drum through pulley to weight without sharp bends or friction points. Any cable misalignment creates stress concentration accelerating cable wear and potentially causing premature failure. However, minor routing variations from original may be acceptable if they reduce friction or improve cable longevity. Balance preservation of original configuration against practical improvements enhancing long-term reliability.

Attach weights to cables using appropriate hardware and technique. Ensure secure attachment preventing weight detachment that allows catastrophic fall damaging case. Test attachment by lifting weight slightly and releasing observing secure retention without slippage or loosening. However, attachment should allow eventual weight removal for future service without destructive disassembly. Balance secure retention against reasonable serviceability achieving optimal compromise.

Testing and Adjustment

After installation, test pulley operation throughout complete weight descent. Listen for clicking, binding, or unusual sounds indicating problems requiring correction. Observe pulley rotation verifying smooth operation without hesitation or irregular motion. Any abnormality suggests misalignment, inadequate clearance, or other installation problems requiring investigation and correction before considering work complete.

Verify movement operation testing throughout multiple cycles. Clock should run reliably without stopping from pulley-related friction. Strike and chime should operate consistently without timing variations suggesting variable power delivery from binding pulleys. Any operational problems suggest inadequate correction requiring additional diagnosis determining whether pulley work was insufficient or whether other movement issues require attention.

Monitor operation over extended period. Immediate perfect operation doesn't guarantee long-term success. Run clock for minimum one week preferably longer before declaring work complete. Extended testing reveals marginal adjustments or installation errors that brief testing may miss. However, balance thorough testing against customer expectations and business needs. Indefinite testing delays clock return creating customer dissatisfaction. Reasonable testing period provides confidence in repair quality while respecting customer's desire for clock restoration.

Alternative Solutions and Considerations

Replacement Pulleys

Replacement pulleys are available from some suppliers. However, suitability varies significantly. Generic pulleys may not accommodate heavy Herschede weights or may have strap openings too small for weight hooks. Verify dimensions carefully before ordering ensuring physical compatibility. However, even correctly sized replacement pulleys may not match original quality or longevity. Rebushing original pulleys preserves authentic components while potentially providing superior long-term durability compared to modern replacements of questionable quality.

Using larger diameter pulleys changes operational characteristics. Larger pulley rotates more slowly making fewer revolutions during weight descent. This may reduce bearing wear rate extending service life. However, larger pulley may not fit in available space or may create cable routing problems. Additionally, using non-original pulleys affects historical authenticity concerns for valuable or collectible clocks. Balance practical advantages against preservation considerations when selecting between original rebushed pulleys versus modern replacements.

For clocks with moderate value where cost minimization is priority, replacement pulleys may be acceptable expedient solution. However, for valuable clocks or where long-term reliability is paramount, professional rebushing of original pulleys provides superior solution justifying additional cost and effort. Make decision based on specific circumstances considering clock value, customer expectations, and long-term service objectives rather than assuming one approach is universally superior.

Movement Condition Assessment

Severely worn pulleys typically indicate movement has experienced substantial operational time. If pulleys show quarter-inch wear, movement pivots likely show significant wear requiring bushing. Fixing pulleys without addressing movement wear creates temporary improvement but doesn't ensure long-term reliability. Movement with severely worn pivots will stop regardless of perfect pulley condition. Comprehensive assessment determines complete service requirements preventing inadequate partial repair requiring callback or customer dissatisfaction.

However, some movements show asymmetric wear patterns. Pulleys may be severely worn while movement pivots remain reasonably good. This occurs when pulleys weren't serviced during prior movement overhauls or when cable maintenance was neglected concentrating wear at pulley bearings. Don't assume pulley wear automatically indicates movement needs complete bushing. Systematic inspection determines actual condition enabling appropriate service recommendation.

For valuable Herschede clocks approaching or exceeding 100 years of age, complete professional overhaul is appropriate regardless of apparent condition. These movements will have accumulated substantial wear requiring comprehensive attention. Pulleys are just one component in system requiring multiple corrections achieving reliable long-term operation. However, for less valuable clocks or where budget constraints limit work scope, selective repair addressing known problems may provide adequate improvement justifying modest investment without requiring complete overhaul expense.

FAQs

How do I know if my Herschede pulleys need rebushing?

Herschede pulleys need rebushing when you hear audible clicking during operation as worn pulley rotates with arbor shifting within enlarged bushing hole creating intermittent contact, whining during winding indicating friction from worn bearings, or discover quarter-inch or more lateral play in arbor when inspecting pulleys showing severe wear. Movement stopping despite apparently adequate condition elsewhere suggests power loss from pulley friction where worn pulley creates variable friction as arbor shifts within bushing hole with some positions creating minimal friction allowing operation while other positions create binding stopping movement. Examine pulleys carefully removing weights and attempting to move arbor laterally where secure pulley shows minimal play with arbor remaining centered in bushing while severely worn pulley allows substantial movement with visible gap between arbor and bushing. However don't assume all old pulleys need service where wear severity varies between installations and clock operated intermittently or serviced periodically shows less severe degradation. Systematic inspection determines actual condition requiring disassembly and careful measurement rather than assuming age alone indicates service necessity.

Can I use larger diameter replacement pulleys?

Yes you can use larger diameter replacement pulleys which changes operational characteristics where larger pulley rotates more slowly making fewer revolutions during weight descent potentially reducing bearing wear rate extending service life though larger pulley may not fit in available space or may create cable routing problems. Movement will still release cable at same rates maintaining proper timekeeping where larger pulley sheave turning more slowly doesn't affect clock operation or timekeeping. However verify dimensions carefully before ordering ensuring physical compatibility where generic pulleys may not accommodate heavy Herschede weights approaching thirty pounds or may have strap openings too small for weight hooks. Using non-original pulleys affects historical authenticity concerns for valuable or collectible clocks where rebushing original pulleys preserves authentic components. For clocks with moderate value where cost minimization is priority replacement pulleys may be acceptable expedient solution but for valuable clocks professional rebushing of original pulleys provides superior solution justifying additional cost and effort making decision based on specific circumstances considering clock value customer expectations and long-term service objectives.

What tools do I need to rebush pulleys?

Rebushing pulleys requires lathe for boring worn hole creating precision round parallel opening and turning new arbor to specifications, arbor press for installing bushing into prepared bore, center drill for creating pilot hole in arbor end during disassembly, drill bits and boring bar for progressive hole preparation, reamer for finishing bushing bore to final dimension accepting new arbor, and appropriate measuring tools including calipers or micrometer verifying dimensions throughout process. Additionally need center punch and hammer for peening arbor ends securing assembly after rebushing. Process is fairly easy if you have lathe and press where you center drill arbor, drill it out to free pulley from stirrup, separate components, chuck pulley in lathe drilling then boring center leaving round parallel hole, press new brass or Delrin bushing into pulley, drill bore and ream for planned arbor diameter, turn new arbor from steel rod, reassemble with light peening. For clockmakers without lathe experience professional service is preferable where specialist with proper equipment completes boring quickly and accurately ensuring optimal results at modest cost compared to value of proper repair preventing future problems from inadequate amateur work.

Should I replace the arbor or reuse the original?

Replace arbor rather than reusing original when arbor shows substantial wear creating reduced diameter in contact area where few thousandths wear may be acceptable depending on total clearance but substantial wear creating stepped or irregular arbor profile requires replacement. Using worn arbor in new bushing accelerates wear creating premature failure making new arbor preferable for long-term reliability where new arbor ensures uniform bearing surface preventing premature bushing wear from irregular contact pattern. Arbor itself wears from constant contact with bushing over decades of operation particularly with thirty-pound weight creating concentrated stress where compound wear with bushing enlarging while arbor reduces creates excessive play manifesting as clicking binding and eventual operational failure. Measure arbor diameter at multiple points along length where unworn areas show original diameter while worn contact areas show reduced diameter and difference indicates material loss from years of bearing friction. For valuable clocks or where long-term reliability is paramount fabricating new arbor from steel rod using lathe provides superior solution ensuring proper bearing surface for decades of future operation justifying modest additional effort and cost.

What causes pulley arbor whining during winding?

Whining during winding indicates friction from worn pulley bearings where as crank turns winding arbor raising weight pulley rotates against worn arbor creating friction producing audible whine. However sound may come from wooden crank handle pivot needing lubrication rather than pulley wear where you distinguish between these sources by applying oil to crank handle pivot and if whining persists pulley wear is likely cause. Some whining is normal during winding but excessive loud whining increasing over time indicates progressive wear requiring attention. Quarter-inch lateral play in severely worn pulley creates variable friction as arbor shifts within enlarged bushing hole during rotation where irregular contact between worn arbor surface and enlarged bushing bore produces friction variations creating audible whine particularly noticeable during winding when rotational speed is higher than during normal weight descent. Additionally worn arbor with reduced diameter in contact areas creates point loading rather than distributed bearing contact concentrating stress and increasing friction. Proper rebushing eliminates whining by restoring precision round bearing surface with proper clearance and uniform arbor diameter distributing bearing load across full contact area reducing friction to normal levels.

Will fixing pulleys make my Herschede run reliably?

Fixing pulleys may make Herschede run reliably if pulleys are primary problem but severely worn pulleys typically indicate movement has experienced substantial operational time where if pulleys show quarter-inch wear movement pivots likely show significant wear requiring bushing. Fixing pulleys without addressing movement wear creates temporary improvement but doesn't ensure long-term reliability where movement with severely worn pivots will stop regardless of perfect pulley condition. Movement stopping despite apparently adequate condition elsewhere suggests power loss from pulley friction where worn pulley creates variable friction as arbor shifts within bushing hole overwhelming improvements from cleaning and adjustment. However some movements show asymmetric wear patterns where pulleys may be severely worn while movement pivots remain reasonably good occurring when pulleys weren't serviced during prior movement overhauls. Systematic inspection determines actual condition enabling appropriate service recommendation where for valuable Herschede clocks approaching or exceeding 100 years of age complete professional overhaul is appropriate regardless of apparent condition. These movements will have accumulated substantial wear requiring comprehensive attention where pulleys are just one component in system requiring multiple corrections achieving reliable long-term operation.

Are Herschede two-weight movements particularly prone to wear?

Yes Herschede two-weight movements are particularly prone to wear because they use heavy weights approaching thirty pounds creating substantial stress on pulley bearings and cable system where cost-saving design developed during World War One concentrates all strike and chime functions on single train creating heavier loading and more complex mechanism. Two-weight system earned reputation among clockmakers as cantankerous when wear develops where excessive bearing stress from heavy weights combined with complex strike mechanism creates multiple potential failure points. Falling weights through case bottom aren't uncommon particularly in movements approaching or exceeding 100 years of age without adequate service where weight crashes damage case creating obvious evidence of prior mechanical failure. While Herschede made many excellent clocks two-weight models require special attention to pulley condition as this represents primary wear point affecting overall reliability. Patent US1250173A describes novel mechanism allowing full quarter chimes using only two weights rather than three-weight system but cost savings came with reliability compromises where as of 2022 vast majority of two-weight Herschedes would have been repaired at least once in their lifespans requiring pulley service, movement bushing, or complete overhaul maintaining reliable operation.