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How to measure

Measure Roller Wheel Diameter

Wheel diameter is the size of the round wheel itself, measured across the center. Measure the wheel only, not the metal housing. Edge profile (flat vs concave) matters for track fit too.

Use Roller Finder All identify guides

What you need

  • Best: digital calipers for a precise reading
  • Preferred: a rigid ruler marked in inches and fractions
  • Acceptable: a tape measure if you can hold it straight through the center

Step by step

  1. Retract the rollers. Turn the adjustment screw counterclockwise until the door lifts slightly off the track.
  2. Remove the panel. Lift up into the top track, tilt the bottom toward you, and set the panel on a padded surface.
  3. Slide the roller out. Remove the retaining screw or release the clip, then pull the whole assembly free.
  4. Find the least worn spot. Rotate the wheel. Flat spots from wear can make the diameter look smaller than it is.
  5. Measure across the center. Place your ruler or calipers through the middle of the wheel, outer edge to outer edge. Do not include the housing or axle head.
  6. Tandem tip: If there are two wheels side by side, measure one wheel only. Do not add both together or measure across both wheels.
  7. Write it down. Record diameter, edge profile (flat or concave), and single vs tandem before you reassemble the door.

Edge profile

The edge is the shape where the wheel touches the track. Wipe dirt off the wheel and the rail first. A dirty track can hide the true edge and make a good roller feel worn. Skip WD-40. Worn concave wheels can look flatter than they started.

Flat roller wheel edge

Flat

Smooth outer rim with no groove. Usually rides a flat or slightly rounded rail.

Concave or grooved roller wheel edge

Concave / Grooved

A U-groove or V-groove in the middle of the rim. Usually straddles a raised track rail.

Measure

  • Wheel diameter through the center
  • Edge profile: flat or concave/grooved
  • Single vs tandem (count of wheels)

Do not use as diameter

  • Housing width, height, or length
  • Both tandem wheels added together
  • Axle heads, rivets, or adjustment screws
  • Wheel material (steel, nylon, etc.)
  • A worn flat spot only (rotate first)

Common mistakes

  • Measuring the housing instead of the wheel
  • Placing the ruler off-center so the reading comes out low
  • Measuring only a worn flat spot
  • Adding both wheels together on a tandem roller
  • Guessing between 1″ and 1-1/8″ without a careful read
  • Calling a dirty or worn concave wheel “flat”

Match a catalog size

Stay in inches and fractions. Round to the nearest common wheel diameter used in our catalog:

  • 27/32″
  • 7/8″
  • 1″
  • 1-1/8″
  • 1-1/4″
  • 1-5/16″
  • 1-1/2″
  • 1-11/16″
  • 1-3/4″
  • 1-13/16″

If you land between two sizes, recheck with the ruler centered, then take a photo with the ruler in the shot instead of guessing.

Photos to take

  • Side view: full roller assembly in focus
  • End view: close-up of the wheel edge (flat vs groove)
  • Diameter view: ruler across the center of the wheel, numbers readable
  • Track view: close-up of the rail the wheel rides on