flanges 14 terminating in legs 16 the surface 13 of the web 12 and the surfaces 15 of the flanges 14 preferably are at right angles so that when the hose is not flexed as in fig2 a smooth cylindrical bore is presented the helical bead 30 is bonded to outward facing surface 17 and end surface 18 of the legs 16 the flanges 14 legs 16 and bead 30 combine to form the rib 28 when the hose is straight the webs 12 meet forming a smooth surface as shown in fig2 when the hose is flexed the wall on the outside of the curve is stretched and the webs are separated as shown in fig3 however the adjacent strips are held together by the bead 30 the plastic of the strip 10 preferably is flexible so that the web 12 may bow when the hose is bent the ribs 28 give a relatively high crush resistant strength to the hose despite the relatively thin walls of the web 12 and flange 14 the sealed together legs 16 of adjacent plastic strips in combination with the flanges 14 and webs 12 thereof form a generally i beam configuration providing increased strength.