What advantage does ribbed innerduct have?
• Supposedly the longitudinal ribs reduce surface area and therefore reduce friction. Ribbed innerduct is still basically a smoothwall product with the major cause of friction being the reel memory of the plastic (or helical set) which causes spiraling of the duct when pulled through a conduit system. Reducing the surface area does little to reduce pulling friction. Corrugated innerduct has no memory and therefore does not spiral resulting in much lower friction than smoothwall products. When blowing cables into conduit the smoother the interior of the conduit the better it is for blowing the cable through it.
