Armstrong Midlength Mk II X-Form 85L 6'4''

View on Armstrong (opens in a new tab)

Build hard Disciplines prone, wing

The Midlength Mk II X-Form has 9 sizes in the current range, from 38 to 130 L. Its slenderness, 3.55, is greater than that of 77% of the 1,895 current boards that publish a length and a width.

Closest boards from other brands

Mount is shown beside each board, never matched on.

Current boards from other brands within ±7% of volume and ±2% of length, and ±2% of slenderness where both publish a width of the Armstrong Midlength Mk II X-Form 85L 6'4'', closest first.
BrandBoardVolume LΔ volumeLength mmΔ lengthSlendernessMount
NaishChimera NVision 88L 6'3"88+3.5%1,905-1.3%3.54 (-0.4%)—
AmosKrUzer V2 Parawing 6'5" 21 1/2" 4 6/16" 85L85+0.0%1,956+1.3%3.58 (+0.8%)—
NorthMidi Pro 2027 6ft 3in90+5.9%1,905-1.3%3.57 (+0.6%)twin-track
SunovaAviator Downwind Elite 6'3" x 21" 5 3/8" @90.1L90.1+6.0%1,905-1.3%3.57 (+0.6%)twin-track
ReedinFeather 2026 88L88+3.5%1,905-1.3%3.49 (-1.8%)twin-track
AmosCypher Wing Parawing 6’4" 21" 4 5/8" 80L80-5.9%1,930+0.0%3.62 (+1.9%)twin-track

Specifications

Every figure is Armstrong's own, read from the source linked in the last row, converted to millimetres and kilograms where the brand prints inches or pounds. Slenderness is computed here, length ÷ width.
FamilyMidlength
ModelMidlength Mk II X-Form
Size, as the brand prints it85L 6'4''
Volume, L85
Length, mm1,930 (6'4")
Width, mm543
Thickness, mm114
Weight, kg4.8
Slenderness (length ÷ width)3.55
Slenderness band3.0–4.0
Mount—
Strap inserts—
Buildhard
ConstructionX-Form precision molded: carbon outer, high-density PVC wrap and rails, ultralight EPS core
Disciplinesprone, wing
Rider weight—
Rider level—
Model year—
Sourcemanufacturer · read 2026-10-02

Every figure above is the manufacturer's published claim, converted to comparable units.

All Armstrong boards · Armstrong on the Board Map · All foilboards