The Challenge Sailcloth High Modulus product line is woven with Fiber 104 in the load bearing direction of the sail. The line is separated into two categories, Low and High Aspect. Our Low Aspect High Modulus Weaves have superior bias strength for higher bias loading that is common in a low aspect sail. The Low Aspect HM Dacrons are woven using more balanced constructions for increased bias strength and excellent recovery. The High aspect weave has superior fill strength for higher leech loadings that are common in high aspect sails. The High Aspect HM Dacrons have the most Interlockings™ of Premium race polyester fabrics. The result is excellent bias stretch resistance, stability and durability.  

Why High Modulus?

The High Modulus sailcloth styles are designed by the Challenge Engineering team to be high performing, strong and durable. The tight weave, exclusive Fiber 104  and proprietary finishing techniques lead to a cloth that makes great sails. 

Fiber 104 is the highest shrinkage polyester yarn used in sailcloth. The Challenge R&D engineering team conducted a collaborative search with leading fiber manufacturers and textile engineers. The purpose of the search was to find the highest shrinkage, highest tenacity yarn in the world. The search resulted in Fiber 104. The high shrinkage makes very tight woven fabrics, with the greatest quantity of fiber Interlockings™. It is much more expensive than the other fibers used in Europe and the United states, and is exclusive to Challenge Sailcloth. 

High Aspect - High Modulus Cloth Specifications 


Low Aspect - High Modulus Cloth Specifications