Abstract: A sub-chassis channel member having a web portion underlying a ski and side portions straddling the sides of the ski is connected to a chassis member overlying the ski. A snow traction cleat located rearwardly of the sub-chassis member and having a web portion underlying the ski is pivotally supported by the chassis member to trail in contact with the snow surface during forward movement and to penetrate the snow surface a limited amount upon rearward movement.A resilient deflector plate extends forwardly and upwardly from the bottom of the web portion of the sub-chassis member to press against the bottom of the ski and to ride over the surface of the snow compacted thereby to prevent build-up of the snow at the leading edge of the sub-chassis member and the traction member.Ice traction blades are pivotally supported by the sub-chassis member to extend parallel to the sides of the ski and have sharp ice penetrating points which trail during forward ski movement.