A guiding device for guiding a fiber texture on an impregnation mandrel of a winding machine, the device including a first radial spacer for placing facing a first cheekplate of the impregnation mandrel, a second radial spacer for placing facing a second cheekplate of the impregnation mandrel, and a cross-member suitable for supporting the first and second spacers, the cross-member including an adjustment system for adjusting the positions of the first and second spacers and suitable for positioning the first and second spacers apart respectively from the first and second cheekplates of the impregnation mandrel so as to hold a first portion of fiber texture that extends along the first cheekplate pressed against the first cheekplate, and a second portion fiber texture that extends along the second cheekplate pressed against the second cheekplate, without blocking rotation of the impregnation mandrel.