These can be used on X-Spec Sport Riders, and came stock on older HR1000, HR1450 and HRT220 models. These are the current wheel tubes for the Trail Rider (HR200). Two of these support tubes will accommodate a bicycle up to a 60” wheelbase X-spec is for racks that were sold between 2009 – 2016 The support tube is square 1.25" x 1.25" Distance between holes: 1.75" 24.5" length Sold as a single If you're not sure what spec you have, please send a photo of your rack to info@hollywoodracks.com