Free Flow Chains have dimensional restraints and so require unique sprockets.
Tsubaki provides sprockets for Dual Plus Chains, sprockets for Double Plus Chains with top rollers, and sprockets for RS Chain with outboard rollers.
Product Lineup
Product Types / Features
Sprockets for Double Plus Chain/Center Roller Chain
Sprockets for Double Plus Chain/Middle Roller Chain. May be used with Double Plus Chain with snap covers.
Details
Sprockets for Dual In addition Chain with Outboard Rollers
Use Sprockets for Dual Plus Chain.
Details
Sprockets for RS Chain with Outboard Rollers
Outboard rollers upon RS Chain with outboard rollers may hinder sprocket hubs depending on the amount of sprocket teeth. Utilize 
this special sprocket instead.
Details
Sprockets for Dual Plus Chain with Top Rollers
R Rollers on Double Plus Chain with Best Rollers may cause interference with regular sprocket teeth. Utilize this special sprocket instead.
Details
Sprockets for RS Chain with Best Rollers
Use Drive Sprockets.
Details