Ski Crampons, Skins, and the NTN Sole
Describes the interface between NTN boot soles and ski-crampon attachment systems, and the skin-tail compatibility considerations specific to free-heel setups — from the makers' own specification documents.
Skins, crampons and the toe: the three specifications a touring binding is now judged on.
Photo: Jordi Costa Tomé / Pexels
The interface the spec sheet doesn't always mention
The New Telemark Norm introduced a standardised boot-sole geometry that solved the binding interface cleanly — and quietly created a secondary question around ski crampons and skin tails.
A ski crampon slots into a binding's crampon receiver and bites hard snow during steep skin tracks. On NTN bindings from Rottefella and 22 Designs, the crampon receiver sits at the toe piece, forward of the bellows zone. Because the NTN sole is wider and squarer at the toe than the old 75mm duckbill, the crampon plate contacts the boot-sole edge differently. Rottefella's published specifications for their NTN bindings confirm compatibility only with crampon models listed per binding generation — cross-generation substitution is not guaranteed, and the dimensional gap matters at anything steeper than moderate pitches.
22 Designs, based in Driggs, Idaho, publish crampon compatibility per binding model on their own spec pages: the Outlaw X accepts 90mm and 95mm crampons, and the stated fit is specific to that binding's toe housing, not to NTN as a category. A crampon listed as NTN-compatible by a third-party retailer is not the same as one validated against a specific binding's receiver geometry.
Skin tails present a separate consideration. Most contemporary skin-tail clips attach to the ski's tail, not the boot, so binding standard has no direct effect there. The relevant variable for free-heel setups is ski-tail width and whether the chosen tail clip spans it. Voile, whose Salt Lake City operation supplies both skins and cable-binding hardware, sizes its tail clips to ski width, not binding type. The boot does not enter the picture at all: the skin's tip loop sits at the ski's nose, well away from the binding and the NTN toe.
The practical upshot, drawn from each maker's own published materials: NTN crampon compatibility is binding-specific ↗, not norm-wide, and skin-tail compatibility is ski-specific. Treating either as a category-level given is where fitment problems begin.
| NTN crampon compatibility | binding-specific, not norm-wide — confirmed by Rottefella and 22 Designs spec pages per binding model |
|---|---|
| 22 Designs Outlaw X crampon spec | 90mm and 95mm receiver, validated to that binding's toe housing |
| Skin-tail clips | sized to ski-tail width, not binding standard — Voile product documentation |
| Split-ski nose clip clearance | not a boot or binding issue — the tip loop attaches at the ski's nose, away from the NTN toe |