Key takeaways
- Short answer: A zero-drop barefoot running shoe RFQ should define the finished heel-to-forefoot relationship, last geometry, internal dimensions, component stack, outsole interface, size grading and sample met…
- Last, outsole, sockliner, lasting and measurement method interact.
- Ask suppliers to state assumptions rather than filling missing fields silently.
Short answer: A zero-drop barefoot running shoe RFQ should define the finished heel-to-forefoot relationship, last geometry, internal dimensions, component stack, outsole interface, size grading and sample method. Do not rely on “zero-drop” as a product label; require measurements and approved references for the exact construction.
Last, outsole, sockliner, lasting and measurement method interact. A last can support the design intent, but the finished shoe is the product the buyer approves. The RFQ must keep last data and finished-shoe data separate.
Define zero-drop for the project
- Measurement points at heel and forefoot.
- Reference surface and shoe condition.
- Whether removable components are installed.
- Component sequence from footbed to outsole.
- Device, conditioning and reporting method.
- Approved tolerances and decision owner.
Ask suppliers to state assumptions rather than filling missing fields silently. Two quotations using the same category label can describe different component stacks and measurement methods.
Separate last and finished-shoe specifications
| Layer | Fields to define | Approval evidence |
|---|---|---|
| Last | Length, girth, forefoot landmarks, toe profile, toe height, heel and bottom geometry | Last code, revision, drawing or controlled measurements |
| Pattern | Seams, allowances, reinforcement, closure and grading | Revisioned pattern record |
| Underfoot stack | Sockliner, strobel or insole, mid-layer where used, outsole and adhesives | BOM and section drawing |
| Finished shoe | Effective internal length, volume, heel-to-forefoot relationship and pair match | Identified sample measurements |
ISO 19409 addresses last dimensions, while ISO 19410-1 addresses in-shoe measurement. Use the official scopes to inform a project method, then document the exact setup.
Specify the fit platform
- Target customer and use case.
- Foot or reference-shoe data used for development.
- Effective length and forefoot landmarks.
- Toe shape and usable toe height.
- Instep volume, heel geometry and closure range.
- Sock assumption and representative reviewer conditions.
A wide outsole outline does not establish internal width. Pattern, lining, reinforcement, seam build-up and lasting can reduce usable space. Approve the finished construction, not a plan-view image.
Control size grading
| Grading field | Buyer question | Evidence |
|---|---|---|
| Last progression | How do length, width, girth and toe profile change? | Size table and selected lasts |
| Pattern progression | Do seams and reinforcements remain at intended landmarks? | Pattern overlay |
| Sole allocation | Which shoe sizes share each outsole component? | Size-allocation table |
| Finished measurements | Which representative sizes will be checked? | Recorded sample results |
| Labels | Do shoe, box and carton conversions match? | Approved artwork and packing check |
Use the size-run QC guide to define representative-size and reorder controls.
Confirm the last-to-sole interface
- Last bottom and outsole cavity geometry.
- Outsole wall, bonding zone and lasting margin.
- Component thickness and compression assumptions.
- Flex-zone position relative to the forefoot.
- Toe spring and rocker where specified.
- Size allocation and transition sizes.
A change to the last, outsole, sockliner or internal construction can reopen measurements and fit approval. Require a written change declaration.
Build the RFQ matrix
| RFQ field | Buyer input | Supplier response |
|---|---|---|
| Development route | Existing, modified or new platform | Available assets and required development |
| Geometry | Last and finished-shoe specification | Feasibility and deviations |
| Size range | Required sizes and conversion table | Grading and sole allocation |
| Materials | Component references and restrictions | Proposed articles and substitutions |
| Samples | Stages, sizes and decisions | Inputs and schedule assumptions |
| Commercial scope | Quantity by style and color | Quote, tooling, testing and exclusions |
Approve controlled samples
- Approve last identity and the measurement plan.
- Approve the development-size geometry and construction.
- Record finished-shoe measurements and fit observations.
- Resolve changes through a numbered revision.
- Approve representative sizes and labels.
- Freeze the specification and physical reference for bulk controls.
Use the OEM last development guide and sample approval workflow for traceable decisions.
Resolve RFQ gaps before supplier comparison
| Open field | Why it blocks comparison | Required buyer action |
|---|---|---|
| Measurement method | Suppliers may report different reference points | Issue one controlled method |
| Last source | Existing and new-last routes have different development scope | Name the source and revision |
| Component stack | Heel and forefoot relationships can be interpreted differently | Provide a section and BOM |
| Size grading | The development size cannot represent the whole range | Define representative sizes |
| Sole interface | Tooling and last compatibility remain unknown | Request an interface review |
| Approval owner | Comments may remain open without a decision | Assign accept, revise and reject authority |
Ask the supplier to return a deviation list beside the quotation. An unanswered field should remain open rather than being treated as an accepted factory assumption.
Preserve the reorder baseline
Archive the last, patterns, outsole revision, component stack, size table, measurements, sample codes, labels and accepted exceptions. For a reorder, request a current change declaration and compare selected sizes with the frozen reference before production release.
Keytop project facts
Keytop was founded in 2006 and has confirmed capacity of 50,000 pairs per month. Custom OEM and ODM production starts at 500 pairs per color and style. Samples are normally developed in 7–14 days after last, sole, materials, sizes and other required inputs are confirmed. Keytop also reports ISO 9001, BSCI, Sedex and GRS credentials; buyers should verify current scope and relevance.
Method and limits
This guide is an RFQ and sample-control framework. It does not set universal geometry, tolerances, fit outcomes, tooling scope or production timing. Confirm the exact method and commercial terms in approved project documents.
FAQ
Is zero-drop defined by the last alone?
No. The last supports geometry, while outsole, sockliner, construction and measurement method affect the finished shoe relationship.
Should the RFQ include representative sizes?
Yes. They help verify grading, sole allocation, internal measurements, pair matching and labels beyond the development size.
What should be frozen before bulk production?
Freeze the last, patterns, materials, component stack, size data, approved samples, measurement method, labels and accepted deviations.
Send the last brief, component stack, size range and sample requirements to discuss a comparable RFQ.
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