ONE & Vintage ONE Installation Guide: Compatibility, Mounting and Initial Setup

ONE and Vintage ONE use the established Tune-O-Matic mounting principle, but correct installation depends on the exact KMS bridge version and the actual guitar hardware beneath it. Bridge shape or guitar model alone is not enough to establish compatibility. If the version has not been chosen yet, start with the ONE & Vintage ONE Product Guide → and return here once the correct bridge is on the bench.

Installation begins by confirming post-center spacing, thread, bridge-hole geometry and any existing bushings. ONE 2 and Vintage ONE 2 additionally require the correct 6-32 locking mount; their locking mechanism secures a compatible installation but must never be used to create fit.

Last updated: 25 August 2026

Compatibility and Bridge Version

Scope of This Guide

This guide covers the installation of:

• KMS ONE 50
• KMS ONE V
• KMS ONE 2
• KMS Vintage ONE 50
• KMS Vintage ONE V
• KMS Vintage ONE 2
• Compatible KMS posts and thumbwheels
• KMS Conversion Posts where required

It applies to post-mounted Tune-O-Matic-style bridges on suitable:

• Solidbody guitars
• Semi-hollow guitars
• Gibson-style instruments
• Compatible custom instruments

It does not cover:

• Floating archtop bridges on movable wooden bases
• Wraparound bridges
• New bridge-hole drilling
• Major body repairs
• Relocating existing posts
• Instruments whose scale geometry is incorrect
• Permanent modification without confirmed measurements

ONE and Vintage ONE

ONE and Vintage ONE share the same installation logic. Body material does not determine the mounting standard; the exact 50, V or 2 version and the selected post system do.

Confirm the bridge version and mounting hardware before installation, then follow the version-specific saddle and locking instructions below.

Which Version Needs Which Mounting

The table describes what each bridge version accepts. It does not describe what the guitar offers — that still has to be measured on the instrument, as set out in the sections below.

Available Mounting Options

Depending on the exact bridge version, KMS Tune-O-Matic bridges can be configured for mounting systems including:

• Traditional 6-32 direct posts
• Metric M4 direct posts
• KMS 6-32 Conversion Posts
• Product-specific locking 6-32 mounting

The exact bridge version must match the selected post system.

Do not mix:

• 6-32 posts with M4 threads
• M4 posts with 6-32 threads
• Nashville hardware with direct-post hardware
• M5 and 10-32 systems
• Large M8 hardware with small-post bridge holes

Similar appearance does not establish compatibility.

ONE 2 and Vintage ONE 2 — Mounting Requirements

The locking ONE 2 architecture uses the KMS 6-32 mounting and locking system.

This means the guitar must provide either:

• A suitable existing 6-32 post installation
• Compatible KMS 6-32 posts
• KMS Conversion Posts creating the required upper 6-32 geometry

ONE 2 must not be forced onto:

• M4 posts
• M5 posts
• 10-32 Nashville posts
• M8 studs
• Damaged or misaligned hardware

The locking mechanism is designed to secure a compatible bridge.

It is not designed to compensate for an incompatible post system.

Traditional Direct Posts

A traditional American ABR-1-style installation commonly uses:

• 6-32 threaded posts
• Separate thumbwheels
• Posts threaded directly into the guitar
• No large pressed-in bridge bushings

A visually similar metric bridge may instead use:

• M4 threaded posts
• Separate thumbwheels

The two systems can appear almost identical.

The threads are not interchangeable.

Bushing-Mounted Systems

Many Nashville-style and metric guitars use posts threaded into pressed-in metal bushings.

These can include:

• Small Nashville-type bushings
• Metric M5 bushings
• Large M8 systems
• Hybrid systems
• Manufacturer-specific hardware

A guitar with bushings does not automatically require their removal.

Secure and compatible bushings should remain in place unless:

• The bridge system is incompatible
• A confirmed conversion is required
• The threads are damaged
• The bushings are loose
• The alignment is incorrect
• Structural repair is necessary

Appearance Does Not Identify the Mounting System

A narrow bridge body can sit on:

• Traditional direct posts
• Metric direct posts
• Conversion posts
• Bushing-mounted hybrid posts

A wider bridge can use:

• Gibson-style Nashville hardware
• Metric inserts
• Manufacturer-specific studs

A photograph from above often does not reveal the complete system.

Measure the hardware directly.

Gibson-Style Bridge Mounting Systems → explains how the architectures differ, and ABR-1 vs. Nashville Bridge → covers the two systems most often confused with each other.

Confirm Compatibility Before Ordering or Installation

Check:

1. Post-center spacing
2. Upper post diameter
3. Post thread
4. Bridge-hole diameter
5. Existing bushing type
6. Bushing outer diameter
7. Bushing depth
8. Available bridge height
9. String spacing
10. Saddle radius
11. Intonation range
12. Required locking system
13. Existing tailpiece geometry
14. Guitar scale position

A bridge that fits loosely over two posts is not necessarily compatible.

Similar 74 mm Spacing Is Not Enough

Many Gibson-style and metric bridges use post spacing close to 74 mm.

Compatibility can still fail because of differences in:

• Post diameter
• Thread pitch
• Bridge-hole diameter
• Bushing type
• Height
• Locking geometry
• Manufacturing tolerance

Post spacing is one measurement within a complete mounting system.

Document and Prepare

Before Installation

Document the existing guitar setup.

Photograph or record:

• Bridge orientation
• Saddle positions
• Saddle orientation
• Post height
• Thumbwheel position
• Tailpiece height
• String path
• Existing post and bushing type
• String gauge
• Tuning
• Action
• Intonation pattern

Take photographs from:

• Above
• Bass side
• Treble side
• Bridge and post area
• Tailpiece side
• Inside any accessible control or body area where the mounting is visible

These references make it easier to return to the original setup if necessary.

Documentation, instrument protection and tension release follow the same principles as any post-mounted Tune-O-Matic installation. The general procedure is set out in How to Install and Set Up a Tune-O-Matic Bridge →. The sections below add what is specific to ONE and Vintage ONE.

Required Tools

Useful tools may include:

• Accurate electronic tuner
• Digital caliper
• String-action ruler
• Thin flat-blade screwdriver matching the 0.8 mm intonation screw slot
• KMS Bushing Extraction Tool (supplied with KMS Conversion Posts)
• KMS Conversion Post Installation Tool (supplied with KMS Conversion Posts)
• KMS two-pin locking tool and 3 mm hex key (supplied with ONE 2 and Vintage ONE 2)
• Additional hex keys as required by the guitar's existing hardware
• Radius gauges
• String winder
• Soft protective cloth
• Stable neck support
• Finish-safe low-tack protection

Use only tools that fit correctly.

An unsuitable tool can damage:

• Screw heads
• Hex sockets
• Threads
• Plating
• Aged finishes
• Saddles
• Retaining clips
• Guitar lacquer

Protect the Instrument

Place the guitar on a stable padded surface.

Support the neck securely.

Protect the guitar top from:

• Falling bridge components
• Screwdrivers
• String ends
• Posts
• Thumbwheels
• Bushing-removal tools
• Conversion Post tools

Nitrocellulose lacquer can be sensitive to:

• Pressure
• Adhesives
• Plasticizers
• Chemicals
• Metal tools

Use only finish-safe protection.

Reduce String Tension

Detune the strings gradually.

When replacing the complete bridge:

1. Reduce the string tension.
2. Move the strings away from the bridge.
3. Hold the bridge so that it cannot fall.
4. Lift the bridge vertically from the posts.

Do not force the bridge sideways.

Resistance may indicate:

• Bent posts
• Post lean
• Corrosion
• Dirt
• Plating build-up
• Misalignment
• Incompatible post geometry
• Previous modification

Identify the cause before applying more force.

Keep the Original Components

Store all removed parts safely.

These can include:

• Bridge body
• Saddles
• Intonation screws
• Shared retainer wire
• Individual retaining clips
• Posts
• Thumbwheels
• Bushings
• Locking hardware
• Washers
• Manufacturer-specific adapters

Do not discard the original bridge or mounting hardware.

A compatible upgrade should remain reversible wherever the guitar itself has not been permanently modified.

Inspect the Existing Mounting

Inspect the Existing Posts

Check for:

• Bending
• Leaning
• Damaged threads
• Uneven height
• Tool damage
• Corrosion
• Excessive movement
• Incorrect spacing
• Mismatched replacement parts

A post can appear straight from above while leaning under string load.

Inspect from:

• Bass side
• Treble side
• Tailpiece side
• Neck side

Post Lean

Traditional direct posts can lean when:

• The wood around the post is compressed
• The bridge has been exposed to high forward load
• The tailpiece produces a steep string angle
• The posts are bent
• The installation holes are damaged
• The bridge has been forced sideways

A new bridge should not be used to conceal post lean.

The underlying mounting condition must be evaluated first.

Inspect the Thumbwheels

Check that the thumbwheels:

• Match the post thread
• Turn smoothly
• Sit flat
• Are not cross-threaded
• Provide stable support
• Have no severe plating damage at the contact face

Both bridge feet must rest correctly on their supporting surfaces.

A damaged or tilted thumbwheel can cause:

• Uneven seating
• Mechanical movement
• Incorrect action
• Bridge rocking

Inspect Existing Bushings

Where pressed-in bushings are present, check for:

• Movement
• Lifting
• Tilting
• Cracked finish
• Damaged internal threads
• Previous adhesive repair
• Corrosion
• Oversized body holes
• Unequal installation depth

Secure bushings do not need to be removed simply because the bridge is being replaced.

Bushing removal introduces risk to:

• Finish
• Wood
• Hole geometry
• Alignment
• Reversibility

For the criteria that genuinely justify replacing a bushing rather than leaving it in place, see When Should Guitar Bridge Bushings Be Replaced? →.

Conversion Posts

Determine Whether Conversion Posts Are Required

KMS Conversion Posts are used when a suitable bushing-mounted guitar must be converted to the upper 6-32 geometry required by ONE 2.

The two principal versions are:

Small Conversion Post

• Lower press-fit diameter: 7.2 mm
• Lower press-fit length: 14 mm
• Upper thread: 6-32
• Upper height: 14 mm

Large Conversion Post

• Lower press-fit diameter: 12.2 mm
• Lower press-fit length: 18.5 mm
• Upper thread: 6-32
• Upper height: 14 mm

The terms 7 mm and 12 mm describe approximate guitar body-hole classes after removal of the original bushings.

They do not describe:

• Post spacing
• Upper thread
• Bridge-hole diameter
• Original stud thread

Measure the Body Holes

After professional removal of the original bushings, confirm:

• Actual hole diameter
• Hole depth
• Center spacing
• Hole alignment
• Wood condition
• Presence of glue
• Previous repair
• Finish condition around the opening

Do not select the Conversion Post by:

• Guitar logo
• Country of manufacture
• Bridge appearance
• Approximate visual size

Measure the actual installation.

Supplied Conversion Post Tools

Every KMS Conversion Post delivery includes two dedicated tools:

• Bushing Extraction Tool: removes the existing press-fit body bushings.
• Conversion Post Installation Tool: supports controlled installation of the new KMS Conversion Posts.

Use each tool only for its intended operation.

Removing Original Bushings

Pressed-in bushings should be removed with the supplied KMS Bushing Extraction Tool using a controlled extraction method.

Do not use:

• Screwdrivers as levers against the guitar top
• Pliers on visible surfaces
• Random bolts that damage internal threads
• Hammering from an uncertain direction
• Heat without finish and material knowledge

The supplied tool makes controlled extraction possible; it does not make every extraction advisable. Professional removal is recommended when:

• The finish is fragile
• The bushings are deeply seated
• Adhesive may have been used
• The body is semi-hollow
• The wood is damaged
• The installation history is unknown

Installing KMS Conversion Posts

Before installation:

• Clean the holes carefully.
• Remove loose debris.
• Confirm the correct diameter.
• Confirm sufficient depth.
• Protect the finish.
• Confirm post-center alignment.
• Use the supplied KMS Conversion Post Installation Tool.

The Conversion Post should enter:

• Straight
• Evenly
• Without uncontrolled force
• Without splitting the surrounding wood
• Without lifting the finish

Reversibility

The KMS Conversion Post installation is designed to remain reversible when:

• The original body holes remain intact
• No permanent enlargement is performed
• The surrounding wood is undamaged
• The original bushings are retained
• Removal and installation are carried out correctly

Reversible does not mean risk-free.

Pressed-in hardware should still be handled professionally.

When Conversion Posts Should Not Be Installed

Stop when:

• The hole is too narrow.
• The hole is too shallow.
• The hole is oversized.
• The holes are misaligned.
• The surrounding wood is cracked.
• The finish is lifting.
• Previous repair material blocks correct seating.
• The guitar requires post relocation.
• The scale geometry is incorrect.

A Conversion Post cannot repair an unsuitable body hole by force.

Prepare the KMS Bridge

Clean the Mounting Area

Before test-fitting the bridge, remove:

• Dust
• Loose finish particles
• Corrosion residue
• Metal debris
• Old polishing compound
• String fragments

Do not allow debris to remain between:

• Bridge and thumbwheel
• Post and bridge hole
• Locking surfaces
• Conversion Post and body

Identify the Bridge Version

Before installation, confirm:

• ONE or Vintage ONE
• 50, V or 2 version
• M4 or 6-32 mounting where applicable
• Saddle material
• Saddle type
• Finish
• Aged or non-aged surface
• Correct string spacing
• Correct radius configuration

Do not combine components from different bridge versions unless KMS explicitly confirms compatibility.

These figures are shared by both families. For body materials, finishes, saddle configurations and weights, see the ONE & Vintage ONE Product Guide →.

ONE 50 and Vintage ONE 50

The 50 versions use the KMS Fat-Flat saddle architecture.

Preserve the supplied saddle geometry and configuration.

Do not alter the saddles unless the exact product instructions call for a defined setup operation.

Permanent saddle work should only begin after:

• Bridge fit is confirmed
• String alignment is established
• Action is set
• Radius is verified
• Intonation range is checked

ONE V and Vintage ONE V

The V versions use KMS V-saddles.

The string is centered through the precision V geometry.

This supports:

• Defined string position
• Broad practical string-gauge compatibility
• Easier gauge changes
• Consistent contact geometry
• No conventional slot filing

Do not file conventional string slots into KMS V-saddles.

ONE 2 and Vintage ONE 2 — Saddle and Locking Architecture

The 2 versions combine:

• KMS V-based saddle architecture
• Functional low-friction saddle surface
• KMS locking bridge system
• 6-32 mounting geometry

The locking system should remain released during initial test fitting and basic setup.

Do not use it to pull the bridge onto incompatible posts.

V+ Functional Surface

Where V+ saddles are used, the contact surface includes an application-specific low-friction treatment.

Do not:

• File the V
• Abrade the surface
• Polish it
• Use abrasive cord
• Apply unknown coatings
• Attempt to recreate the finish after damage

The saddle is a finished functional component.

Test-Fit and Mount

Test-Fit the Bridge Without Strings

Place the bridge vertically onto the posts.

Confirm that:

• Both bridge holes engage correctly.
• The bridge reaches both thumbwheels.
• The body does not bind.
• The posts do not need to be pushed sideways.
• The bridge can move vertically for adjustment.
• The bridge sits without severe rocking.
• The intonation screws remain accessible.
• The locking mechanism remains released.

Do not force the bridge over posts that are:

• Too wide
• Too narrow
• Misaligned
• Bent
• Incompatible in diameter

Bridge-Hole Clearance

The bridge holes must allow installation and adjustment without excessive play or binding.

Too little clearance can cause:

• Difficult installation
• Binding during height adjustment
• Side loading
• Post damage
• Finish damage
• Incomplete seating

Excessive clearance can contribute to:

• Rocking
• Unstable positioning
• Mechanical movement

The locking ONE 2 system can secure the bridge only after compatible geometry has been established.

Bridge Orientation

Install the bridge in the product-specific KMS orientation.

Do not rely on universal myths such as:

• All ABR-style screws must face the pickups.
• All Nashville-style screws must face the tailpiece.

The correct orientation depends on:

• Bridge design
• Screw access
• Saddle travel
• Tailpiece clearance
• Product geometry

The KMS screw-retention system is part of the intended orientation.

Individually Retained Intonation Screws

All KMS Tune-O-Matic bridges use side-inserted intonation screws secured individually by retaining clips.

Each screw and corresponding saddle are retained separately.

KMS does not use one shared traditional ABR-1 retainer wire.

The system can be described as:

• Individually retained intonation screws
• Clip-retained intonation screw system
• Side-inserted screws secured by individual retaining clips
• Captured intonation screws

Inspect the Retaining Clips

Before installation, inspect each clip for:

• Correct seating
• Deformation
• Damage
• Contamination
• Missing components
• Incorrect orientation

The screw should remain retained while still allowing its intended adjustment.

Do not remove the clips unnecessarily.

Clip-Retained Does Not Mean Maintenance-Free

An incorrectly seated or damaged clip can cause:

• Axial screw movement
• Mechanical noise
• Loss of retention
• Restricted adjustment
• Component loss during service

Individual retention removes the shared wire.

It does not remove the need for correct assembly.

Do Not Substitute Clips

Use the correct KMS retaining components.

A clip of the wrong:

• Diameter
• Thickness
• Spring force
• Material
• Groove relationship

may not retain the screw correctly.

Initial Saddle Positions

Before stringing, confirm that every saddle has usable intonation travel.

A reasonable initial pattern may place:

• Treble saddles farther toward the nut
• Bass saddles farther away from the nut

The final pattern depends on:

• String gauge
• String construction
• Plain or wound third string
• Tuning
• Action
• Scale geometry

Do not finalize the saddle positions visually.

Saddle Orientation

Where a saddle is reversible, changing its orientation can alter the available compensation range.

Do not reverse a KMS saddle casually.

The procedure may affect:

• Intonation screw
• Retaining clip
• Saddle contact geometry
• V orientation
• Surface system
• Component sequence

When additional travel is required, first check the complete setup.

Disassembly should follow current KMS product instructions.

Install the Bridge

Place the bridge onto the compatible posts.

Begin with:

• Locking system released
• Conservative bridge height
• Intonation screws accessible
• Thumbwheels supporting both sides
• No string tension forcing misalignment

The bridge should rest on the thumbwheels or intended support surfaces.

It should not hang from the locking mechanism.

ONE 2 Locking Contact

The ONE 2 locking mechanism should engage only after:

• Correct 6-32 posts are confirmed
• Bridge holes seat fully
• Thumbwheel support is correct
• Action is established
• Orientation is correct
• String alignment is confirmed

The mechanism secures the finished setup.

It does not establish compatibility.

String Alignment, Action and Radius

Install the Intended Strings

Use the string gauge and tuning in which the guitar will normally be played.

Changing them later can alter:

• Neck relief
• Action
• Intonation
• String radius
• Saddle positions
• Playing feel

Guide each string through the tailpiece and over the center of its saddle.

Bring the strings gradually toward pitch.

Check String Centering

Confirm that each string remains:

• Centered on the saddle
• Clear of adjacent saddle features
• Aligned with the neck
• Correctly positioned over the pickups
• Suitably spaced from the fretboard edges

Pay particular attention to:

• Low E or lowest extended-range string
• High E
• Plain third string
• Strings near pickup pole-piece edges

V-Saddle Centering

On KMS V-saddles, allow the string to settle naturally into the V.

Do not force it sideways.

Do not create a new slot to correct an underlying alignment problem.

When the outer strings do not align correctly, inspect:

• Bridge centering
• Post alignment
• Neck alignment
• Nut position
• Tailpiece position
• String spacing

The saddle should not be permanently altered to compensate for an incorrectly positioned bridge.

Conventional Saddle Work

Where a conventional saddle configuration requires final slotting, perform it only after:

• Bridge position is confirmed
• Outer-string alignment is established
• String spacing is planned
• Radius is understood
• The correct tool and technique are available

Saddle slotting is permanent precision work.

It affects:

• String position
• Radius
• Contact
• Stability
• Break angle
• Tone
• String life

Professional work is recommended when the saddles are not already finalized.

Tune Gradually

Bring all strings toward pitch in stages.

During this process, check that:

• The bridge remains fully seated.
• Both posts remain stable.
• Both thumbwheels remain in contact.
• The bridge does not twist.
• The strings remain centered.
• No saddle moves unexpectedly.
• No retaining clip becomes displaced.

Check Neck Relief

Neck relief must be evaluated before final bridge height.

With the guitar tuned to pitch, hold the lowest string down at the first fret and at the fret where the neck meets the body. Measure the gap between the top of the 8th fret and the underside of the string.

Gibson publishes 0.25–0.30 mm (.010–.012 in) as its factory neck-relief reference. KMS does not specify a value of its own; use this as a starting point only. The workable relief depends on the neck itself, fret condition, string gauge, tuning and playing force.

An unsuitable neck condition can cause:

• Excessive action
• Lower-fret buzz
• Middle-fret buzz
• Choking
• Misleading bridge adjustments
• Poor intonation

The bridge should not be raised excessively to compensate for an incorrectly adjusted neck.

Set the Bridge Height

Adjust action through the two thumbwheels or the corresponding post-support system.

Make small changes.

For substantial height adjustment:

• Reduce string tension.
• Support the bridge.
• Protect the finish.
• Use the thumbwheels correctly.
• Retune afterward.

Do not grip plated or aged thumbwheels with unsuitable pliers.

Bass and Treble Height

The bass side commonly requires more clearance than the treble side.

The bridge can therefore sit at a slight bass-to-treble angle.

This is normal when it produces the intended string action.

The bridge does not need to appear visually horizontal relative to:

• Guitar top
• Pickup rings
• Tailpiece
• Body binding

Measure the strings rather than judging only by appearance.

Measure the Action

Measure action from the top of the fret to the underside of the string.

Gibson publishes the following factory action references at the 12th fret:

• Low E: approximately 2.0 mm (5/64 in)
• High E: approximately 1.2 mm (3/64 in)

KMS does not specify values of its own; use these as starting points only.

Use a string-action ruler or feeler gauge rather than estimating by eye, and measure with the guitar held in normal playing position — a neck can move slightly between lying flat and standing upright.

Additional measurements can help verify the complete radius.

The correct action depends on:

• Neck relief
• Fret condition
• Fretboard radius
• String gauge
• Tuning
• Picking force
• Bending
• Player preference

Check the String Radius

Measure the actual strings.

Do not infer the final radius only from the bridge-body curve or visible saddle tops.

The result depends on:

• Saddle geometry
• String diameter
• Bass-to-treble action
• Fretboard radius
• Compound radius
• Existing saddle slots
• V-saddle behavior

Compound-Radius Necks

On a compound-radius neck, the string radius at the bridge is normally flatter than at the nut.

The correct bridge radius follows the projected geometry of the fingerboard.

Do not automatically copy the nut radius at the bridge.

Tailpiece Height

On guitars with a separate Stop Bar, tailpiece height controls the string path behind the bridge.

Set it so that:

• Strings remain securely seated.
• Studs retain sufficient engagement.
• Tailpiece remains stable.
• The strings do not create unnecessary interference.
• The resulting feel suits the instrument.

Lowering the tailpiece increases the break angle.

Raising it reduces the break angle.

Maximum break angle is not automatically the best setting.

Rear Bridge-Edge Contact

Inspect each string between saddle and tailpiece.

The saddle should remain the intentionally defined bridge contact point.

Clearance between the string and rear bridge edge is generally preferable where the geometry allows it.

Light contact is not automatically a fault.

It should be corrected when it causes:

• A pronounced second contact point
• String damage
• Finish wear
• Friction
• Mechanical noise
• Contact with screw heads
• Restricted adjustment

Raise the tailpiece when additional clearance is required.

Top-Wrapping

Top-wrapping is optional.

It changes:

• Break angle
• String path
• Tailpiece contact
• Surface wear
• Perceived feel

It is not required for correct ONE or Vintage ONE installation.

Top-wrapping can mark the upper surface of the tailpiece.

Inspect the Intonation Screw Area

Confirm that the strings do not interfere with:

• Intonation screw heads
• Retaining clips
• Rear bridge edge
• Saddle movement

The clip-retained system must remain unobstructed and serviceable.

Intonation and Locking

Prepare for Intonation

Set intonation only after:

• Intended strings are installed.
• Strings have stabilized.
• Guitar is at the intended tuning.
• Neck relief is correct.
• Action is established.
• Bridge height is stable.
• Tailpiece position is established.
• String alignment is correct.
• Locking mechanism remains released where adjustment is still required.

Use an accurate tuner.

Hold the guitar in a normal playing position where practical.

Correct Tool for the Intonation Screws

The intonation screws use a 4-40 UNC thread and a slotted drive with a 0.8 mm-wide slot.

Adjust them with a correctly fitting thin flat-blade screwdriver. The blade should engage the slot fully to avoid damaging the screw head.

Intonation Procedure

For each string:

1. Tune the open string accurately.
2. Check the 12th-fret harmonic as an octave reference.
3. Fret the note at the 12th fret with normal pressure.
4. Compare the fretted pitch.
5. Adjust the saddle in a small increment.
6. Retune the open string.
7. Check the fretted note again.
8. Repeat until the best practical result is reached.

The fretted note is essential because intonation compensates for the pitch change created when the string is pressed to the fret.

The procedure itself is common to all Tune-O-Matic bridges and is described in general terms in How to Install and Set Up a Tune-O-Matic Bridge →. What follows applies specifically to the KMS clip-retained intonation screw system.

Adjustment Direction

When the fretted 12th-fret note is sharp:

• The effective string length is too short.
• Move the saddle away from the nut.

When the fretted note is flat:

• The effective string length is too long.
• Move the saddle toward the nut.

The direction in which the screw must be turned depends on bridge orientation.

Follow the actual saddle movement.

Adjust in Small Steps

Small saddle movements can create clear pitch changes.

Use a repeated cycle:

1. Measure.
2. Adjust.
3. Retune.
4. Measure again.

Do not force a resistant screw.

Resistance can indicate:

• High string load
• Contamination
• Damaged thread
• Damaged clip
• Saddle binding
• Incorrect component
• End of travel

Slightly reduce string tension where required.

Individually Retained Screws During Adjustment

The retaining clip secures the screw axially.

It does not replace correct adjustment technique.

During intonation, verify that:

• Screw rotates correctly
• Saddle moves predictably
• Clip remains seated
• Screw does not move excessively sideways
• Saddle remains supported
• No component binds

Insufficient Intonation Range

When a saddle reaches the end of its travel, check:

• String gauge
• String condition
• Tuning
• Bridge orientation
• Saddle orientation
• Neck relief
• Action
• Post position
• Scale geometry
• Bridge compatibility

A damaged or twisted string can create unstable intonation.

Replace the string before modifying the bridge.

Do Not Judge by the Saddle Staircase

A familiar staggered pattern is common.

It is not the objective.

The correct pattern depends on:

• Gauge
• Core construction
• Winding
• Plain or wound third string
• Tuning
• Action
• Fretting pressure

Judge the result by measured pitch.

Reversing a Saddle

Some saddle designs can be reversed to gain additional travel.

On a KMS bridge, this may require controlled disassembly of:

• Retaining clip
• Intonation screw
• Saddle
• Product-specific components

Do not remove or reinstall retaining clips with unsuitable tools.

The clip must remain:

• Undamaged
• Correctly seated
• Properly matched to its groove

When additional travel is required, follow current KMS service instructions or consult a qualified technician.

Final Mechanical Check

Check for Mechanical Noise

After intonation, inspect:

• Saddle stability
• Intonation screw movement
• Clip seating
• Bridge seating
• Thumbwheels
• Posts
• Bushings
• Tailpiece
• Strings behind the bridge

A mechanical rattle should be located directly.

Do not attribute it automatically to:

• Brass
• ZAMAK
• Saddle material
• Aged finish

Finalizing ONE 2 Locking

Finalize the locking mechanism only after:

• Correct 6-32 mounting is confirmed
• Bridge is fully seated
• Thumbwheels support both sides
• Action is correct
• String alignment is correct
• Intonation is complete
• No further substantial height change is expected

Use the KMS two-pin locking tool supplied with the bridge. Its pins are spaced 5.4 mm apart and engage the two holes in the locking nut; the tool is driven with the supplied 3 mm hex key. Both parts are included with every ONE 2 and Vintage ONE 2 delivery.

Tighten the locking elements:

• Evenly
• Progressively
• With controlled hand force
• Without deforming the bridge
• Without forcing the posts

The mechanism should secure the bridge.

It should not create the fit.

Do Not Overtighten

Overtightening can damage:

• Small fasteners
• Threads
• Tool sockets
• Plating
• Post surfaces
• Locking components

A precision locking system does not require uncontrolled force.

Recheck After Locking

After final locking, verify:

• Tuning
• Action
• Bridge seating
• Intonation
• String alignment
• Screw access
• Tailpiece clearance
• Mechanical noise

The bridge may settle slightly as the locking surfaces engage.

Correct any resulting setup change before the instrument is returned to use.

Pickup Height

A bridge-height change also changes the string-to-pickup distance.

After action is finalized, inspect pickup height.

Check clearance during:

• Normal fretting
• Hard picking
• String bends
• Palm muting

Pickup height influences:

• Output
• Dynamic response
• String balance
• Tone
• Magnetic pull
• Physical clearance

Complete Playing Test

Test:

• Open strings
• Chords
• Single notes
• Light picking
• Hard picking
• String bends
• Vibrato
• Palm muting
• Clean amplification
• Distorted sounds

Evaluate:

• Action
• Buzzing
• Choking
• Intonation
• String alignment
• Attack
• Note separation
• Sustain
• Playing comfort
• Mechanical stability

Care and Next Steps

Routine Care

For normal care:

• Wipe away sweat after playing.
• Use a soft clean cloth.
• Remove dust from recesses carefully.
• Keep screw heads clean.
• Keep threads free from contamination.
• Avoid excessive moisture.
• Dry the hardware before storing the guitar.

Do not allow cleaning fluid to collect around:

• Saddles
• Intonation screws
• Retaining clips
• Posts
• Thumbwheels
• Locking components
• Bushings

Nickel and Aged Nickel

For nickel-plated and aged-nickel hardware:

• Avoid abrasive polish.
• Avoid steel wool.
• Avoid aggressive metal cleaner.
• Preserve intentional patina.
• Remove harmful sweat deposits gently.
• Do not polish aged areas back to mirror brightness unless deliberately intended.

Visual aging is not automatically a defect.

Gold and Black Nickel

Thin decorative finishes can change through:

• Friction
• Tool contact
• Sweat
• Repeated cleaning

Use a very soft cloth.

Avoid abrasive products.

Do not attempt to make every aged or worn area visually uniform.

V and V+ Saddles

Do not:

• File
• Polish
• Scrape
• Use abrasive cord
• Apply unknown lubricants
• Reshape the contact

Keep the V clean and inspect it under good light when a string-contact problem is suspected.

Retaining Clip Care

During string changes and service, inspect each clip for:

• Secure seating
• Deformation
• Corrosion
• Damage
• Contamination

Do not perform routine removal.

Replace a damaged clip only with the correct KMS component.

Post and Thumbwheel Care

Check periodically for:

• Post lean
• Movement
• Damaged threads
• Uneven thumbwheels
• Corrosion
• Locking-system movement
• Loose Conversion Posts

Do not apply thread-locking compound unless specifically approved.

Bushings and Conversion Posts

Inspect the surrounding finish and wood for:

• Lifting
• Cracks
• Movement
• Tilting
• Gap formation

A moving insert or Conversion Post is a mounting problem.

It should not be corrected by tightening the bridge lock more forcefully.

String Changes

When replacing strings with the same gauge and tuning:

• One-at-a-time replacement can help preserve the established setup.
• Complete removal provides better access for cleaning.

Support the bridge when all string tension is removed.

After restringing, recheck:

• Tuning
• Action
• Intonation
• Bridge seating
• Tailpiece height
• ONE 2 locking system

Gauge or Tuning Changes

Changing gauge or tuning can require a new setup.

Recheck:

• Neck relief
• Action
• Radius
• Intonation
• Saddle travel
• Tailpiece height
• String alignment

V-saddles support easier gauge changes because they do not rely on individually filed conventional slots.

The complete guitar setup can still change.

Common Installation Mistakes

Avoid:

• Ordering by guitar model alone
• Assuming every 74 mm bridge is compatible
• Mixing M4 and 6-32 hardware
• Mixing 10-32 and M5 hardware
• Forcing the bridge onto misaligned posts
• Using the ONE 2 locking system to create compatibility
• Removing secure bushings unnecessarily
• Selecting Conversion Posts by brand alone
• Hammering directly on Conversion Posts
• Installing into damaged body holes
• Filing KMS V-saddles
• Abrading V+ surfaces
• Removing retaining clips unnecessarily
• Substituting incorrect clips
• Setting action before checking neck relief
• Intonating with unstable strings
• Setting saddle positions by appearance
• Maximizing tailpiece break angle automatically
• Overtightening small locking screws
• Ignoring post lean
• Treating active corrosion as harmless patina

Troubleshooting

Bridge Does Not Fit Both Posts

Check:

• Spacing
• Post diameter
• Bent posts
• Post lean
• Bridge-hole diameter
• M4 vs. 6-32
• Hybrid mounting system

Do not force the bridge.

Bridge Rocks

Check:

• Thumbwheel contact
• Post fit
• Bushing stability
• Locking system
• Debris
• Bridge-hole clearance

ONE 2 Will Not Lock Correctly

Check:

• Correct 6-32 posts
• Full bridge seating
• Thumbwheel support
• Locking-component position
• Post damage
• Incorrect installation height

Do not tighten harder to overcome incompatibility.

One Saddle Rattles

Check:

• Intonation screw
• Retaining clip
• Saddle position
• Screw thread
• Contamination
• End of adjustment travel

String Does Not Remain Centered

Check:

• Bridge alignment
• Post position
• Neck alignment
• Nut position
• Correct saddle
• V geometry
• Tailpiece path

Do not file the V as the first response.

Correct Intonation Cannot Be Reached

Check:

• String condition
• String gauge
• Tuning
• Action
• Neck relief
• Saddle orientation
• Bridge orientation
• Scale geometry
• Post position

String Breaks at the Saddle

Inspect for:

• Surface damage
• Burr
• Contamination
• Incorrect string path
• Damaged saddle
• Excessive rear-edge contact

Do not modify the saddle without identifying the exact break point.

When Professional Installation Is Recommended

Professional work is advisable when:

• Pressed-in bushings must be removed.
• KMS Conversion Posts must be installed.
• Body holes are damaged.
• Posts lean or are bent.
• The guitar finish is fragile.
• The guitar is semi-hollow.
• Threads are damaged.
• Neck relief is uncertain.
• Frets are uneven.
• Saddle slotting is required.
• Compatibility cannot be confirmed.
• Correct intonation cannot be reached.
• Permanent modification would be necessary.

Stop whenever installation requires unexplained force.

The KMS ONE Installation Principle

ONE and Vintage ONE use the established Tune-O-Matic architecture as a mechanical foundation.

Their final performance depends on the complete relationship between:

• Bridge-body material
• Saddle system
• Intonation screw retention
• Posts
• Thumbwheels
• Bushings
• Tailpiece
• Strings
• Guitar geometry
• Setup

Final Verification

Before considering the installation complete, verify:

• Correct mounting standard
• Stable posts
• Suitable bushings
• Correct bridge version
• Saddle geometry
• String alignment
• Neck relief
• Action
• Radius
• Tailpiece height
• Intonation
• Locking where applicable

Recheck the complete setup after the guitar has returned to stable tuning.

FAQ

How do I tell whether my guitar has 6-32 or M4 posts?

Not by looking. A traditional 6-32 installation and a metric M4 installation can appear almost identical from above. The reliable check is the thread of the existing post and thumbwheel, measured with a caliper or compared against a known 6-32 or M4 fastener. Do not test an unknown thread by running a KMS thumbwheel onto it — a mismatched start damages both parts.

Can ONE 2 be fitted to a guitar with pressed-in bushings?

Only through a confirmed conversion. ONE 2 and Vintage ONE 2 require a 6-32 upper post. Where the guitar uses pressed-in bushings, the original inserts have to be removed and KMS Conversion Posts fitted in the class that matches the measured body hole. The locking mechanism never creates that fit.

Do I have to remove bushings that are already secure?

No. Secure, correctly aligned bushings with undamaged threads should stay in place. Removal is justified only by an incompatible bridge system, a confirmed conversion, damaged threads, a loose fit, incorrect alignment or structural repair.

Which way round does the bridge go — screws toward the pickups or the tailpiece?

Neither rule is universal. Install the bridge in the orientation specified for the actual KMS product. The correct direction follows from bridge design, screw access, available saddle travel and tailpiece clearance, not from a convention.

When is the ONE 2 locking system tightened?

Last. It stays released through test fitting, stringing, alignment, action, radius and intonation, and is finalized only once no further substantial height change is expected. Recheck tuning, action, alignment and intonation afterwards, because the bridge can settle slightly as the locking surfaces engage.

Can I change string gauge without filing the V saddles?

Yes. The V geometry is the finished string contact and supports a broad range of common gauges without conventional slotting. The rest of the setup can still change: recheck relief, action, radius, intonation, saddle travel and tailpiece height after any gauge or tuning change.

A saddle has run out of intonation travel. What now?

Check the setup before modifying anything. Review string gauge and condition, tuning, bridge and saddle orientation, neck relief, action, post position and scale geometry. A damaged or twisted string produces unstable intonation — replace the string first.

Is the KMS Conversion Post installation reversible?

It is designed to be, provided the original body holes stay intact, nothing is permanently enlarged, the surrounding wood is undamaged, the original bushings are kept and both removal and installation are carried out correctly. Reversible does not mean risk-free: pressed-in hardware remains workshop work.

Why must a V+ surface not be polished or cleaned abrasively?

The V+ contact carries an application-specific low-friction treatment. It is a finished functional component, not a decorative surface, and the treatment cannot be recreated once it has been abraded away.

Does ONE use a shared ABR-1 retainer wire?

No. Every side-inserted 4-40 intonation screw is retained individually by its own clip. That removes the shared wire as a potential loose component, but each clip still has to be correctly seated — a damaged or displaced clip causes axial screw movement, mechanical noise and loss of retention.

Which tools are supplied with the bridge, and which do I need to provide?

Every ONE 2 and Vintage ONE 2 delivery includes the two-pin locking tool and a 3 mm hex key. Every KMS Conversion Post delivery includes a Bushing Extraction Tool and a Conversion Post Installation Tool. Everything else is standard setup equipment: a tuner, a caliper, a string-action ruler, radius gauges, a thin flat-blade screwdriver matching the 0.8 mm intonation screw slot, and finish-safe protection for the guitar top.

Related Guides

• ONE & Vintage ONE Product Guide: Choosing 50, V or 2 →
• Gibson-Style Bridge Mounting Systems →
• ABR-1 vs. Nashville Bridge →
• How to Measure Guitar Bridge Post Spacing →
• When Should Guitar Bridge Bushings Be Replaced? →
• How to Install and Set Up a Tune-O-Matic Bridge →