Free Flow Chains have dimensional restraints therefore require special sprockets.
Tsubaki offers sprockets for Dual Plus Chains, sprockets for Dual 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 Dual Plus Chain/Center Roller Chain. May be used with Double Plus Chain with snap covers.
Details
Sprockets for Dual Plus Chain with Outboard Rollers
Use Sprockets for Dual Plus Chain.
Details
Sprockets for RS Chain with Outboard Rollers
Outboard sprockets Rollers upon RS Chain with outboard rollers might interfere with sprocket hubs depending on the number of sprocket teeth. Use this special sprocket instead.
Details
Sprockets for Dual In addition Chain with Best Rollers
R Rollers on Dual Plus Chain with Best Rollers may cause interference with standard sprocket teeth. Use this special sprocket instead.
Details
Sprockets for RS Chain with Best Rollers
Use Drive Sprockets.
Details