Idler Sprocket

Tsubaki offers a variety of different types of idler sprockets to fit a variety of applications, including the following standard types:

  • Ball Bearing Idlers
  • Needle Bearing Idlers
  • Bronzed Bushed Idlers (Oilite, Bronze, Brass)
  • Non-Metallic Idlers (Nylon/ Nyloil, Derlin and other bushed idlers using custom materials)
  • Set Screw Locking Type Idlers


Tsubaki can offer idler sprockets for use with Roller Chain and Engineered Class Chain. Large or small, Tsubaki can supply almost any idler sprocket, including custom made-to-order. We only use quality bearing units when creating the idler sprockets.


Adjustable Idler Sprockets Are Used To:

  • Obtain proper chain tension when neither driving nor driven shaft is adjustable.
  • Guide chain around an obstruction.
  • Prevent whipping action in the slack span of chain transmitting an uneven load.
  • Bring about greater chain wrap around a small sprocket, particularly if it is lower sprocket in a vertical drive.
  • Take up slack chain caused by normal chain wear.
  • Provide for reversed direction of rotation of a sprocket in contact with the outside of the chain


Idler sprockets should not rotate at greater speeds than are allowable for drive sprockets of the same size. They should be mounted in contact with the “slack” span of chain, whenever possible. Mount them on the outside of the chain when the arc of the chain wrap on the smaller sprocket would otherwise be less than 120º. It is advisable that idler sprockets have at least three teeth in mesh with the chain. Inside mounted idlers usually account for quieter operation, especially if centers are short and speed is moderately high.

Idler Sprockets