The forklift wheels are the “feet” of the entire machine. Once the wheels fail, the consequences go far beyond simply being “unable to push”—they can include drifting, longer braking distances, cargo shifting and falling, increased risk of vehicle rollover, and cascading damage to the steering system, bearings, and axle assembly. Treating wheel replacement as a mere consumable purchase often ends up costing much more in terms of downtime, accidents, and repair expenses.

This article expands upon and refines the original text by adding details on “the three-dimensional criteria for replacement,” threshold values for different operating conditions, measurement tools and procedures, as well as post-replacement follow-up inspection and documentation methods—making it easier to implement directly on-site.

I. Why do wheels determine the “fate” of forklifts? Let’s first take a look at three types of hidden costs.

• Safety costs: Increased risk of skidding and rollover, longer braking distances, and heightened risks of cargo sliding, collisions, and personal injuries.
• Efficiency Costs: Increased rolling resistance, stiff steering, heightened driver fatigue, longer single-trip handling times, and reduced daily production output.
• Maintenance costs: Misalignment and play can transmit impact forces to the bearings, pivot pins, steering mechanism, and frame, resulting in a situation where "a minor issue with the wheels leads to major repairs for the entire vehicle."

Conclusion: Wheels aren’t “used until they break”; rather, they’re “calculated for replacement.”

II. Criteria for Replacement Based on Three Major Dimensions (recommended to be included in the inspection checklist)

2.1 Tire Tread Wear: Let the Numbers Speak

It is recommended to establish the red line based on the “new wheel reference dimensions,” and to set different thresholds in combination with operating conditions.

• General operating conditions: Wheel surface thickness wear ≥ 30% —— Replace directly.
• Heavy-duty/high-frequency use: Wear ≥ 20% —— Enter the replacement window (it is recommended to keep a spare tire in advance).
• Cold storage facilities and oil-contaminated/corrosive environments: Wear ≥ 15% —— triggers the red line (material aging occurs more rapidly, posing higher risks).
• Wear Bias Detection: A unilateral deviation exceeding 3 mm is considered wear bias. Even if the total wear has not yet reached the threshold, we recommend replacement and traceability of the underlying cause.

Tip: Uneven tire wear can lead to vehicle deviation, overload on the steering system, and abnormal stress on the wheel hub/bearing—these are “precursors to accidents.”

2.2 Structural Damage: Discontinue Use Upon Detection

• Cracks: Radial cracks exceeding 50 mm in length or deeper than 5 mm in PU/rubber; through-cracks in nylon.
• Debonding/Loosening: The gap between the wheel hub and the tire tread exceeds 2 mm, and turning the wheel produces a “clunking” sound or noticeable wobbling.
• Rust/Deformation: The area of wheel hub rust is ≥ 30%, or the bearing housing is deformed, causing jamming and shaking.

If any of these issues arise, we recommend immediately taking the vehicle offline for troubleshooting: first address the root cause (bearing/shaft pin/frame alignment), then replace the tire to prevent rapid recurrence of the problem with the new tire.

2.3 Performance Anomalies: The Silent Killer Is Even More Dangerous

• Decreased stability: lagging, unusual noises, and drifting, with lubrication/cleaning proving ineffective.
• Vibration and Noise: Even on smooth road surfaces, there’s still a “clanging” sound; under full load, deformation exceeds 5 mm and rebound is poor.
• Grip and Braking: Slipping occurs on clean surfaces; the braking distance under no-load conditions exceeds 2 meters, and under full-load conditions exceeds 3 meters (it is recommended to calibrate according to the company’s safety standards).
• Special requirement: If static electricity accumulates or conductivity fails to meet the required standards in explosion-proof/static-free areas, replace the tires/wheel materials with those that comply with the requirements.

A word of caution: Performance anomalies often occur well before the tires reach their wear limit. Replacing tires in a timely manner can typically save you from much higher repair and accident costs.

3. How do we determine the “individuality thresholds” for different vehicle models/operating conditions? (On-site feasible methods)

The force distribution varies significantly among different forklifts (electric/internal combustion, counterbalance/stackers) and different wheel positions (drive wheels, load-carrying wheels, steering wheels). It is recommended to use the “risk coefficient” method to adjust the threshold values.

Risk coefficient = Load rating × Frequency of use × Ground roughness × Severity of environmental conditions (oil contamination/ cold storage/chip debris)

The higher the risk coefficient, the earlier the replacement threshold should be adjusted—for example, from 30% to 20% or even 15—and the inspection frequency should be increased from weekly to daily.

4. More Precise Measurement Tools and Procedures (Recommended SOPs)

4.1 Tool List (Low-Cost, Readily Available On-Site)

• Dial Caliper/Depth Gauge: Measures diameter, tread thickness, and main groove depth (for patterned tires).
• Diameter Reference Record: Original diameter of the new wheel (or new wheel sample/data sheet).
• Chalk/Marker: Use to mark measurement points and wear directions for easy re-measurement and comparison.
• Thermometer (optional): Use to check for bearing overheating and abnormal heating on wheel surfaces.
• Inspection Checklist/Logbook: Records date, wheel position, wear data, operating conditions, and handling results.

4.2 Three-Step Measurement Method (Fixed Measurement Points Recommended)

1. Step 1: Establish a baseline—Record the new wheel diameter/wheel face thickness (at least once per wheel position).
2. Step 2: Fixed-point re-measurement—Measure at the same location each time (it is recommended to take readings at three points on the wheel surface: left/middle/right). Record the maximum and minimum values to quickly identify uneven wear.
3. Step 3: Compare with the red line—If the wear on the drive wheel diameter exceeds 10% to 15%, or if the thickness reaches the corresponding threshold, it’s time to enter the replacement window. If structural damage or performance abnormalities occur, replace the component immediately.

4.3 Work-hour and Operating Condition Records (Allowing Tires That “Seem Okay” to Be Removed from the Production Line Early)

In “harsh environments” such as 24-hour shifts, highly corrosive conditions, heavy debris accumulation, and cold storage facilities—where visual inspection alone can easily lead to misjudgments—we recommend establishing a lifecycle ledger based on working hours/mileage metrics. Once the average lifespan of the same vehicle model under identical operating conditions stabilizes, we can proactively stock spare tires at the “predicted replacement point,” thereby reducing unexpected downtime.

V. The “finishing touches” after wheel replacement (determining how long the new wheel will last)

• Replace in pairs: It is recommended to replace the drive wheels and steering wheels in pairs to prevent deviation and differential wear caused by diameter differences.
• Select tires based on operating conditions: For heavy loads or high-frequency use, prioritize high-quality PU or steel-belted tires; for low-temperature conditions, choose formulations with anti-cracking properties; and if oil contamination is present, ensure the tires are oil-resistant and hydrolysis-resistant.
• Re-examine the cause of uneven wear: If feather-like, unilateral uneven wear is observed, prioritize inspecting the axle pin, bearings, frame alignment, wheel positioning installation, and driving habits (sharp turns, abrupt braking, and aggressive cornering).
• Re-tightening and Re-inspection: Retighten the bolts to the specified torque, conduct a test run to re-inspect braking performance and vehicle deviation, and record the data.
• Record-keeping and tracking: Each time, update the record date, wheel position, model, operating conditions, and wear cause to create a traceable data loop.

Appendix A: Tire/Wheel Inspection Checklist (Template—can be directly copied and used)

Appendix B: Quick Reference for Replacement Decisions (to be posted in the workshop for greater clarity)

• Wear reaching the threshold: General use 30% / Heavy-duty use 20% / Refrigeration oil contamination 15% —— to be implemented according to operating conditions.
• Wear exceeding 3 mm: Proceed directly to “Replace + Investigate Cause.”
• Cracks/Delamination/Hub deformation: Discontinue use immediately.
• Catching and abnormal noises, worsening braking performance: First troubleshoot; if troubleshooting is ineffective, replace immediately.