Definitions of a pole according to Gill Athletics

[Chris]

http://www.gillathletics.com/%5CPVNews%5Cweb%20definitions.pdf

1. The mandrel ? they vary in length and diameter just as the poles do. These are what the fiberglass is wound or rolled on to. The bigger the mandrel diameter (directly impacts Moment of Inertia of the pole) the less the wall thickness required to get a given stiffness. You need a certain wall thickness to maintain integrity of the pole. Typical as the poles get longer and into the stiffer (lower flex number or higher weight rating) the larger the mandrel (as mandrel get bigger the number get smaller ? an 8 has a larger diameter than a 10). Certain vaulters prefer certain mandrel size ? how it fits and fells when they grip it. Most elite vaulters will specify a certain length; flex rating and possibly mandrel size. This mandrel size also related to the pole tip size.

2. Spiral wraps ? or narrow spiral wound strips of fiberglass are applied to the mandrel. The number, type of glass and how they are wrapped all impact pole properties. This is a patented process; other manufacturers use various other procedures.

3. Full body wraps ? typically a rectangular piece that is the full length of the pole and is designed to achieve a certain number of complete wraps around the poles circumference when rolled

4. The Sail Piece ? a section of fiberglass that varies in length depending on the pole ? up to full length and is shaped like a sail or trapezoid. The location, size and shape of these sail piece have a major impact on how and where the pole bends when used. This varies between pole models and manufacturers.

5. Flex Number ? a number that is the distance a pole deflects with a given weight (usually 50 lbs) is suspended in the middle of the span. The span being the distance between the supports. Spans vary with the length of poles.

6. Weight Rating - Poles are rated in 5 lb increments by most manufacturers since there is a range of flexes that will be grouped into this weight class. An example might be a 14? pole ? the 5 lb increment might cover a range of flexes within one cm. ? example 16.0 plus or minus .5 would all be rated the same weight (15.5 to 16.5). Ratings to tenths of pounds would not be accurate with respect to significant figures and the accuracy of measurements.

7. Materials - The most widely used fiberglass are S-Glass and E-Glass. The generic properties of these can be found on many web sites. Most fiberglass used in pole manufacturing is resin impregnated. It is the resin that bonds (cooking or fusion process) the layers of glass
together. We specify the resin type and percentage. Gill is also the largest producer of carbon
fiber poles.