Double butted aluminum U6 tubing with disc brake tabs, replaceable hanger all of this for Cyclo-Cross performance. U6 aluminum fork with disc tabs, Shimano 105 rear derilleur with Tiagra STI shifters with an FSA 46 x 36t crankset, 9 speed 12x25 cassette for smooth shifting performance. Ritchey Comp wheel set with Maxxis Raze tires will get you to the finish line over the toughest terrain. Available in 7 sizes (44cm-60cm) measured center to top.