SHIBATA Idler Gear 28TSHIBATA (#R31S101) Idler Gear 28T Feature: For: Triple idler system of the GRK5 R This is an optional 48 pitch, 28 tooth idler gear designed for use with the triple idler system of the GRK5 R conversion kit. By replacing only the upper idler gear with this 28T gear, you can use smaller pinion gears ranging from 24T down to 17T, which are not compatible with the standard 24T gear. (Note: Two 28T idler gears are required for this setup see 1 below.) By