The XR1.5 is identical to the XR1.0 except Syncros uses lightweight alloy rims instead of carbon. This wheel is a great choice for a lightweight 29" all-around alloy wheel. It's designed for cross country racers and aggressive trail riders. The XR is a tubeless-ready rim that offers superior acceleration and stiffness to weight ratio. The CNC machined center lock hubs feature DT Swiss serviceable hubs that have stainless steel bearings all around for reliable, long life.