Chain Hoist Shaft Mount 4:1 Reduction

Upgrade your sectional or rolling garage door with the JR-ST Chain Hoist Manual Door Operator. Designed for jackshaft mounting on a 1" torsion bar, this robust manual hoist delivers a 4:1 mechanical reduction—ideal for commercial or industrial doors requiring reliable manual lift capability.

The JR-ST operator includes all essential components for a smooth and secure installation, including a 22" #41 roller chain, 26' of hand chain, wall bracket, shaft collars, and more. Its external chain and sprocket drive system ensures high-efficiency operation, while its compatibility with a wide range of mounting types provides installation flexibility.

Whether you’re setting up a new door system or replacing an existing one, the  JR-ST chain hoist offers the durability, performance, and ease-of-use professionals trust.

? Product Highlights:

• Model: JR-ST

• Part Number: 9-8-10N

• Alternate SKU: JR-ST-1

• Mounting Style: Jackshaft mount for 1" torsion bar

• Reduction Ratio: 4:1

• Chain Type: #41 Roller Chain

• Includes:

  • 22" of #41 roller chain

  • 26 ft. of hand chain

  • Chain keeper

  • 2 shaft collars

  • Wall bracket

  • 1/4" shaft key

  • Sprocket

?️ Installation Overview

Shaft Mounted (1:1, JR-ST, JR-RD, JRG):

• Mount unit to shaft and align sprockets

• Use shaft keys, set screws, and collars to secure in place

• Install roller chain with connector link

• Secure wall bracket to reduce swing

Wall Mounted (3:1 or 4:1 models):

• Attach sprocket to shaft

• Mount hoist to wall ensuring proper chain tension

• Align sprockets, install roller chain accordingly

General Chain Setup:

• Loop hand chain around pocket wheel (add extra if door >14ft)

• Adjust to hang ~1 ft. from floor

• Use pliers to open/close a link to complete loop

• Secure chain with wall-mounted chain keeper