Two data jobs in one shoe: technology attributes as the comparison basis, and a size/width run as the buying decision — where FEDAS and the pools help, and where they stop.
A running shoe looks like a simple product until you try to describe it in data. A customer wants to know the drop, whether it's a neutral or stability shoe, how heavy it is and how much cushioning it carries — and then they need it in exactly their size and width. Two data jobs in one product: a set of technology attributes that only matter if they're comparable across brands, and a size-and-width run that only works if every variant is modeled cleanly.
Product data for running shoes lives on two axes at once: technology attributes as the comparison basis, and size-width variants as the buying decision. This is a focused corner of the broader sports & outdoor challenge, and it overlaps heavily with the footwear data logic — but running pushes both problems to their extreme.
Running is a category where customers genuinely shop on specs. Drop, stack height, weight and pronation support are the attributes a serious runner filters and compares on. The trouble is that no two brands describe them the same way:
To let a customer filter by drop or compare cushioning across brands, you first have to pull those attributes out of inconsistent feeds and map them to one shared set. That mapping is the comparison basis — without it, the filters on your shop are lying.
The second axis is fit, and it's where the SKU count explodes. The same foot maps to different EU, UK and US numbers depending on the brand, widths are labeled inconsistently (or not at all), and half sizes appear in some ranges but not others. A clean running catalog has to solve all of it:
| Sizing layer | The problem | What a clean catalog needs |
|---|---|---|
| Size scales | EU / UK / US differ per brand for the same foot | One master scale with per-brand mapping |
| Widths | Narrow / standard / wide labeled differently or missing | One consistent width scheme across brands |
| Half sizes | Present in some runs, absent in others | Modeled explicitly, not merged into full sizes |
| Variants | Each size/width is a sellable unit with its own barcode | Every combination as a linked variant with its own EAN/GTIN |
Get this wrong and stock, ordering and returns all drift. The key insight: each size-and-width combination is its own variant with its own EAN/GTIN, but all of them must stay linked to one parent shoe so the technology attributes are shared, not duplicated.
FEDAS classifies the article as a running shoe and gives the assortment a shared merchandise-group language — genuinely useful for structure. Buying-group pools (Intersport, Sport 2000) deliver clean master records for the big listed running brands. But both stop well short of what a running catalog needs: FEDAS carries no drop, no stack height, no cushioning attribute and no size-width matrix, and the pools cover only the listed brands — not the smaller labels, own brands or accessories. The technology depth and the sizing logic are exactly the layer no standard hands you, which is why the manual work never disappears. It's the same gap the whole footwear category lives with, just sharper because runners compare on numbers.
Productbay is built for exactly this two-axis job — comparable attributes plus clean variants — with linked attributes as the core of the sizing logic:
The payoff is a catalog where a customer can filter by drop, compare cushioning across brands and land on exactly their size and width — because the attributes are comparable and the variants stay linked. Productbay is built for specialist retailers running multi-supplier, multi-channel catalogs, from mid-sized shops to large chains.
Drop, stack, cushioning, weight — plus every size and width mapped to one scheme. See how Productbay pulls running shoe technology into comparable attributes and keeps size variants linked, in a 30-minute walkthrough.
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