Bike:
Bike:
Winter Frequently Asked Questions
What’s the difference between sintered and extruded bases?
Ski and snowboard bases are made out of a polyethylene (a plastic polymer) material that everybody calls P-Tex for short, though it is actually the trademarked name for only one particular company’s polyethylene recipe. Since all facial tissues are referred to as Kleenex by the same token, no feelings are hurt and no lawsuits flung. The properties of a base are determined by its particular manufacturing process, of which there are two.
Extruded bases are made by rapidly heating up the P-Tex to a high temperature and then forcing it through a slot to create sheets of the desired thickness which are pressed together to form the base. It is a faster and easier process, so extruded bases are often found on entry-level or more recreational downhill products. Bases of this type are not very wax-absorbent at all (nor are sheets of plastic) but they are inexpensive and easy to produce. Extruded bases (especially on snowboards) are more likely to exhibit warpage (being convex or concave) which can negatively affect the ride.
A sintered base is formulated by compressing polyethylene pellets under low pressure over a long period of time, causing them to fuse together. This process, unlike extrusion, creates a base with microscopic open spaces between the polyethylene molocules into which wax can penetrate and reside. These bases are faster as a result, provided they are regularly given a healthy dose of glide wax, as well as being lighter and stronger than extruded counterparts. Almost all nordic skis today use sintered bases because excess friction is a much bigger and uglier monster on flat ground. Performance alpine, telemark and snowboard products also use sintered bases. They are always flatter than their extruded counterparts.
