Mountain Bikes

Custom Built Steel Frames

O’Leary mountain bikes are built for all day comfort and performance – in the dirt. Currently all frames are 100% fillet brazed, using a 44 millimeter headtube, and 73 millimeter standard English threaded bottom bracket. Drop-outs come in a variety of styles but typically we use thru-axle styles or traditional quick release models from the top machinists in the country. The geometry of our mountain bikes are tuned to the rider’s preferences but use a range of 69-71 degree head angle and 72-73 degree seat-angle for the frames. The O’Leary mountain bike is steeped in decades of off road designs with attention to modern advancements in front suspension, disk brakes, dropper-seat posts and tire designs. Let us build your next ride with 100% True Temper steel tubes and honor America’s most significant contribution to cycling with a made-in-America mountain bike!


  • Hand-built, custom, True Temper American-made made CroMoly steel frame
  • 44 mm head tube
  • Paragon dropouts