Allen 20mm Back To Back Dynamic Block. The sheaves face opposite directions to allow two control lines to run at a maximum of 180 degrees to each other. Held together with a strong stainless steel side strap and nylon mouldings ensures the block will not separate even under two very high opposing loads. The strength of the design lends itself to be tied around the middle in the slight V shape, meaning it can be used in applications such as triangle backstay systems found on sports boats. One of the more popular applications is in a dual pole and spinnaker launcher system such as the system commonly found on a 49er. Bearings - Dynamic Blocks feature our patented bearing system which uses twin rows of stainless-steel ball bearings running on a stainless-steel rail. This provides a superior load-carrying ability and longevity when compared to other bearing systems which run on a plastic rail. Becket - Our 20 & 30mm blocks offer a large central rivet which not only reduces the overall weight but also offers a rope friendly attachment, perfect as a tie-off point when being used in a cascade system.
