JMP Aluminum Racing chain wheels Whoever attaches great importance to low weight, quality and design, will hardly find better chainrings. The JMP aluminum racing chain wheels are made of 7075 T6 aluminum, which is mainly used in aviation. This aluminum alloy is characterized by its enormous strength, tightness and light weight. Milling in the tooth base of the sprocket guarantee optimum self-cleaning. These milling operations ensure that the dirt can not settle between the teeth and thereby the chain and sprocket do not wear as quickly as normal aluminum sprockets. Apart from the "protective effect", the sprocket is not only more durable, but also looks more high-quality. - high performance - unique quality - high quality - light weight