Catrike Clamp On Sport Return Idler Kit by TerraCycle - Terracycle Clamp on idler mount is composed of a Return idler, Single sided clamp on chain keeper, custom stainless bolt, spacers. This kit is for Catrike Riders who wish to eliminate all of their return side chain tube by running the chain path through an additional idler. The kit can be mounted either in front of or behind the trikes cross arm depending on how where the boom is set for length.