The use of phenolic resins for idler pulleys in automotive engines is increasing because reducing weight to improve fuel consumption is important. There is a trade-off for thermal shock resistance and abrasion resistance. In a contaminated environment such as with road dust and in the use of metal molds, it has been found that phenolic resin is a suitable material because of its mechanical strength, dimensional stability, chemical resistance and cost. A phenolic resin blend was developed for idler pulleys that balances superior wear resistance with high machinability. A material with improved abrasion resistance to foreign materials and improved thermal shock resistance was developed. Moreover, since the pulley is molded directly to the bearing, the performance of the idler is dependant on the proper shape of the components. The basic bearing performance was confirmed, and an optimum design for durability, size and weight was achieved. An idler made of a phenolic resin pulley was developed.