TerraCycle newest Idler is the Sport Series Idler which has been years in development. We wanted to give the same attributes to this idler that our Elite Series Idlers have been known for but in a more economical package. With ballistic nylon side plates and an aluminum cog, these idlers should give years of trouble free service and improve most drivetrains that had stock non-toothed idlers. Sizes of the Idlers are 2.75 inch diameter with a 15 tooth aluminum cog, or 2.5 inch diameter with the 14 tooth cog ($6.00 upcharge on the smaller idler). 8mm ABEC 7 shielded bearings are standard.