Sometimes with innovation there is a sacrifice with some associated items becoming obsolete. Thru-axles are a perfect example of that. They are a stronger and offer more precise wheel to frame interface and have become standard on almost all mountain bikes and now some road and cross bikes as well. However, with this came the challenge of mounting specific racks, trailers, and even using your bike on a trainer. The Robert Axle Project has been offering some simple solutions that lets you use your more modern bikes with formerly incompatible trailers, carriers and trainers for some time.