Derby Dust Pinewood Derby Speed Wheels (4X) Asset Flawless inner hub for consistent wheel rotation. Mold marks are removed while retaining near full tread/beaded edges with outer diameter of 1.174". Outer wheel diameter will always be 1.170 or greater. Machined outer tread near identical to uncut wheels. We do not reduce the width of the wheel. Since most packs do not allow this modification. Most are very descriptive about this modification. The overall width is factory 0.360" Edge of wheel is left factory to retain maximum strength as to reduce flexion and also to keep it within the specifications of the most strict of wheel rules. 2 Step machined outer hub machined to give the benefits of a rounded hub, but retain factory spacing. Smaller gap needed