Shop › Kartboy 6-Speed Front Gear linkage Bushings Image 1 of 1 Kartboy 6-Speed Front Gear linkage Bushings £65.00 These shifter bushings for the STI 6-Speed do not reduce shift throw, but provide a more solid shift feel. Add To Cart Added! These shifter bushings for the STI 6-Speed do not reduce shift throw, but provide a more solid shift feel.