142x

The impacts of this engineering shift were immediate and profound:

Because the axle threaded into the exact same position every time, disc brake rotors were always perfectly centered between the pads. The impacts of this engineering shift were immediate

What made the 142x standard particularly brilliant was its execution of backwards compatibility and ease of use. While the total width of the axle was 142mm, the actual spacing between the interior frame faces remained at 135mm. The extra 7mm was used for built-in guides or "shelves" in the frame dropouts. This allowed riders to simply drop the wheel into the frame, and it would automatically align with the axle bore, making wheel installation faster and less clumsy than the old quick-release system. Furthermore, many hub manufacturers were able to create simple end-cap conversion kits, allowing riders to upgrade their existing 135mm wheels to the new 142mm standard without buying entirely new equipment. The extra 7mm was used for built-in guides