Tube clamp is adjustable to adapt to different chainstays diameters and profiles. Alloy U clamp that holds the pulley can also rotate for better chain alignment adjustment. 54 and 42T rings are alloy with a steel 34T inner ring. 38T timing rings. About 35mm outside dia, 25mm wide, tapered groove 10mm, 5mm deep.
Cartridge bearings on both sides.
If you don't see the ring you need, contact us for pricing. Rings are all 7 and 8 speed compatible. Neoprene protector protects chainstay from chain slap. Velcro closures for easy installation and removal. For standard size chainstays.