Tire Duty Classes, Decoded: Soft/Medium/Hard & DH/Enduro/Trail/XC

A grouping layer on top of casing and compound

See the Tire Casings & Rubber Compounds guide first for what casing and compound actually describe and why every brand names its own tiers — this guide is about the class chips built on top of those brand-specific names, which group them into rider-facing categories for the Tires-tab sub-filters.

The two classification axes

• Compound class — soft, medium, or hard — groups a tire's rubber tier by relative grip/durometer positioning.
• Casing class — DH, enduro, trail, or XC — groups a tire's carcass tier by relative duty/protection positioning.

Neither class feeds the compatibility engine — they're purely a shopping/filter convenience layered on top of the same brand-native compound/casing fields the tire itself already carries.

Why a brand's own label doesn't compare across brands

The whole reason this grouping layer exists is that a brand's own tier name tells you where a tire sits within that brand's own lineup, not where it sits against a different brand's tire. The clearest example in the catalog: Continental names one of its compound tiers simply "Soft" — but sourced comparative reviews and Continental's own technology page place that tier in the middle of Continental's compound range, with a separate "Supersoft" tier below it. So a Continental tire literally labeled "Soft" is classified here as a medium-class compound — not because the catalog disagrees with Continental, but because "Soft" is Continental's own relative name for its middle tier, and comparing it directly to another brand's "Soft" tier by name alone would be misleading. Whenever you're comparing tires across brands, compare by class chip, not by the tier name printed on the tire itself.

Why some values stay unmapped

Not every value in a tire's compound or casing field gets sorted into a class. A value is only mapped when a manufacturer's own naming, a fetched maker or press page, or an already-sourced note states its class unambiguously. A value is deliberately left unmapped when any of the following is true:

• It describes a construction, bead, or reinforcement detail rather than a hardness or duty claim — a compound-count descriptor like a "dual compound" or "tri-compound" label, for instance, says how many rubber layers a tread uses, not how soft or hard any of them are.
• It names two target classes jointly, with no principled way to pick just one — one real example in the catalog is a WTB casing tier sourced as chosen by "XC and trail riders" alike; there's no honest way to file that under only one of those two classes, so it's left unmapped rather than guessed.
• It spans two durometers by design rather than reducing to one — a dual-compound tread built with a harder center strip and a softer shoulder strip (a real, sourced Kenda construction) simply isn't a single hardness value to classify.
• No sourced signal exists for it at all yet.

An unmapped value isn't a data gap or a mistake — it means that tire's compound or casing genuinely doesn't correspond to a single class the way a Continental "Endurance" or a Maxxis "3C MaxxGrip" tier does. A tire with an unmapped value simply won't match any of the soft/medium/hard or DH/enduro/trail/XC chips until the chip is reset back to "All," at which point it reappears normally.

The "Gravity" naming pattern

Several brands use the word "Gravity" somewhere in a casing tier's name — Schwalbe's Super Gravity, Specialized's GRID Gravity, Kenda's Advanced Gravity Casing, and others. None of these are literally named "Downhill" or "DH," and "gravity riding" in modern mountain bike marketing spans enduro through DH without being DH-exclusive — so every Gravity-named casing tier in the catalog is classed as enduro, applied the same way regardless of which brand uses the word. It's a consistent rule applied identically across every brand that uses that naming convention, not a brand-by-brand judgment call.

How BuildMyMTB uses this

Compound and casing classes are purely a Tires-tab filter/display convenience. Picking a "soft" compound tire or a "DH" casing tire can never turn your build's compatibility verdict red, yellow, or anything else — the actual tire-related checks the engine runs are about width against wheel and fork clearance, covered in the fork-travel-adjacent guides, and have nothing to do with compound or casing at all.

Practical takeaways

• Use the class chips, not the tire's own tier name, when comparing duty or grip level across brands.
• Remember a brand's own "Soft"/"Trail"/etc. label is relative to that brand's own lineup — Continental's "Soft" being their middle tier is the textbook example.
• An unmapped compound or casing value isn't missing data — it's the catalog declining to guess at a class the source material doesn't unambiguously support.
• Compound and casing classes never affect your build's compatibility verdict — they're a shopping convenience only.