Electronic Technical Report issued on: 08/17/2026
⚠️ DISCLAIMER: This diagnosis is for informational purposes only. The handling of chemical adhesives and solvents for shoe repair must be carried out in adequately ventilated environments and with the aid of personal protective equipment.
The defect manifests as a tear or structural failure of the upper mesh, typically located in the forefoot area, at the metatarsophalangeal joints. The following symptoms may be observed:
| Symptom | Detailed Description | |---|---| | Visible tear | A rip in the fabric, often with frayed threads, progressing from a thinning of the weave to a macroscopic break. | | Specific location | The tear predominantly occurs where the shoe flexes during gait (the natural "flex point" of the forefoot) or at the edges of heat-sealed TPU reinforcements. | | Internal wear | In some cases, the damaged area may show fabric thinning or internal roughness before the tear. | | Symmetry | The tear may be present on both shoes in similar positions, suggesting a mechanical fatigue issue. |
For an accurate analysis, it is crucial to rule out some less probable causes or those that would require a different approach:
The structural failure of the mesh in ON Cloud 5 and Cloud 6 is predominantly due to a mix of mechanical stress and friction, with varying probabilities:
| Probability | Cause | Why | Key Signal | Quick Check | Often Happens When | |---|---|---|---|---|---| | 45% | Mechanical fatigue from cyclic flexing | The polyester mesh, designed for lightness and breathability, is subjected to repeated tensions during the foot's push-off phase. Areas where the fabric changes density create stress concentration points, leading to progressive failure. | Symmetrical tear at the natural flex point of the forefoot, with frayed threads but no signs of external impact. | Put on the shoe and flex the forefoot: the tear is exactly where the fabric bends most. | The shoe is used intensively for running or prolonged walking, accumulating thousands of flexion cycles. | | 30% | Localized internal friction | Continuous rubbing of toes (especially big toe or pinky), untrimmed nails, or socks with thick seams acts as an abrasive on the inner wall of the mesh, weakening it. An imperfect fit (e.g., wide foot or high instep) also increases internal pressure. | Localized wear primarily on the medial (big toe) or lateral (pinky) side, with fabric thinning before rupture. | Inspect the inside of the upper in the affected area for roughness or wear of the inner lining. | N/A | | 15% | Delamination and cutting from heat-sealed TPU edge | The junction between the flexible mesh and rigid TPU reinforcements creates a virtual cutting line. Repeated flexing of the shoe pushes the mesh against the rigid edge of the TPU, accelerating the rupture. | A clean, linear cut that precisely follows the profile of the heat-sealed plastic reinforcement on the upper. | Carefully analyze the junction edge between the TPU and the mesh. | N/A | | 10% | Minor causes: external abrasion or yarn defect | Micro-dust or debris infiltrating the mesh can act as abrasives. Rarely, a yarn defect can lead to premature failure. | Asymmetrical tears, visible scratches on the sole or protective profiles indicating external contact, or sudden failure without progressive wear. | N/A | N/A |
Tools for Repair (if you decide to act):
Operational Decision:
If the tear is symmetrical in the flex zone (45-30% probability), you can attempt a DIY repair with adhesive patches and specific glue (parts cost approximately €10-20). If the damage is clean and localized near the TPU reinforcement (15% probability), or if you prefer not to risk it, we recommend consulting a specialized cobbler for professional intervention (estimated labor cost of €25-45). If the mesh wear is extensive throughout the upper and the shoes have accumulated many kilometers, complete replacement remains the most suitable choice.
Remember that for this type of adhesive, drying time and strong initial pressure are crucial: before joining the parts, let the solvent evaporate for about 10-15 minutes until the glue is almost dry to the touch, then press firmly.
ReeFix provides this diagnosis EXCLUSIVELY for educational and informational purposes.