Universal Spider with SRAM 8-Bolt Interface
 

 
This universal spider features a SRAM 8-bolt interface and a 104 mm bolt circle diameter (BCD), making it compatible with a wide range of mountain bike chainrings as well as Gates belt drive sprockets.
 
The chainring or sprocket can be mounted on either the inside or the outside of the spider. Countersunk holes on both sides ensure a clean, seamless look regardless of the mounting position.
 
The resulting chainline depends on the spindle length of the bottom bracket:
 
 
 
Inside Mounting (WIDE Spindle): Yields a 43.5 mm chainline, making it ideal for narrow frames and internally geared hubs like Shimano Alfine or Enviolo.
 
 
Outside Mounting (WIDE Spindle): Increases the chainline to 52.0 mm— with some extra spacers also fits Rohloff hubs.
 
 
This design enables a narrow Q-factor while maintaining a wide chainline.
 
Material: Precision CNC-machined from 7075-T6 aluminum.