This thru axle is for attaching an Old Man Mountain rack to the rear of your fat bike that has a 12 mm thru axle with 1.0 mm thread pitch and 229 mm or 217 mm length. We partner with The Robert Axle Project to supply our thru axles.

• Diameter of thru axle is 12 mm.
• Thread pitch is 1.0 mm.
• True length of axle is 229 mm, but can be shortened to 217 mm with the included tapered spacer.