SIDI · Boot Parts
The SIDI Hyper Extension System is a replacement block system built for SIDI boots that use this mechanism. Designed to help limit ankle and foot hyperextension, it supports the boot’s structure and intended protective performance while keeping natural mobility in mind.
Made to swap in for worn or damaged components, this part helps control rearward movement without unnecessarily restricting flexibility. It’s offered in Black, Red, and White, with size ranges from 37-39 through 48-50, and it fits the Crossair, Crossair HD Enduro, and Crossair X boots as listed by SIDI.
This hyper extension block system is designed to help limit ankle and foot overextension. By managing rearward movement at the ankle/foot area, it adds a functional layer to the boot’s support system while still aiming to preserve natural mobility during use.
Replacing worn components can help keep the boot functioning as intended. The Hyper Extension System is built to support the boot’s structure and protective performance, helping restore the purpose of the original system when the existing block is damaged or worn out.
This replacement part is listed by SIDI as fitting the Crossair, Crossair HD Enduro, and Crossair X boots. Hardware is included for straightforward installation, making it easier to refresh the system without sourcing additional mounting pieces separately.
| SIDI Reference | 345 |
|---|
| SIDI Crossair |
| SIDI Crossair HD Enduro |
| SIDI Crossair X |
Fitment as listed by SIDI for this part.
| Helps limit ankle and foot hyperextension. |
| Supports boot structure and protective performance. |
| Maintains flexibility while enhancing stability. |
| Replacement component for worn or damaged parts. |
| Includes hardware for easy installation. |
As listed by SIDI for this boot part.
