Practically all of the best gravel bikes, mountain bikes and e-MTBs feature some form of internal cable routing these days. This can range from simply having the brake hoses go through the frame to complicated aero-biased designs that hide all cables inside bars, stems and frames in ever more complicated setups.
Though often neat looking, they have made the life of a modern mechanic somewhat more complicated, and for those at home it can be a daunting task to change something as straightforward as a gear cable. Most professional mechanics would, in the not-too-distant past, have a selection of bent wires, fishing lines and adapted spokes to help feed lines through frames and hook them out of often tight, difficult to access ports. Park Tool's latest IR-1.3 Internal Cable Routing Kit aims to change that and make living with internal routing a bit less stressful.
