Specific Chain Rolling Friction Factors (f r)
Chain Rolling Friction:  Rolling Friction of chain can be determined by formula:
                             f r = Rolling friction of chain.
f r = Ad  where     A = Factor from below.
         D                    d = Diameter of bushing, inches.
                              D = Diameter of chain roller, inches. 

Type of Bearing For Chain Rollers Factor A*
Rollers Not Lubricated Rollers Greased
Cored iron or steel on cold finished steel** .50 .35
Bored iron or steel on cold finished steel .40 .25
Bored bronze bushing on cold finished steel -- .20
Plastic bushed on cold finished steel .25 --
Roller bearing with smooth hardened races -- .09
Ball bearing with smooth hardened races -- .06

* - Based on rollers with smooth faces operating on smooth, clean steel tracks and includes reasonable allowance for flange and hub frictions.
** - Based on smooth cored holes made with dry sand or painted cores.