The Aaron Ross AM models feature a 20.25" toptube and CRMO downtube, headtube anddropouts. Sunday's orignal Wave downtube can also be foundthrough out theline. The rear end lengthof 13.25" allows a younger and smaller rider to manuever the bike more easily. Each bike has a sealed Mid BB and sealed9T cassette hub to help a rider ride more. The AMs feature aftermarket Sunday Word Bubble grips and Odyssey Twisted PC pedals. These bikes have the look and feel of a modern pro's bike. Don't let the AM name fool you, consider this bike to be at the upper end of the low end category.