Rear sprockets two-metal JT Sprockets TWINSTAR chain 520 for Yamaha YZ 125 99-25 grey color

The JT TWINSTAR bi-metal rear sprockets combine the lightness of Ergal with the strength of Steel. For their realization, an effective coupling system of the two parts was used, such as to allow the use of a very low height steel toothed track.

The materials used by JT for the construction of these crowns are:

- for the internal part, the Ergal 7075 T6, machined with CNC machines. Maximum lightness and a high degree of finish, which includes a fine satin finish and gray or orange colored anodizing, depending on the model.
- for the toothed external part, C49 steel with black finish, hot galvanized.

The high quality standard requires that each piece undergoes, during the 25 processing stages, as many as 10 dimensional and quality checks in order to always ensure maximum durability and precision.