Genuine Specialized replacement carbon seatstay for 2025+ Stumpjumper 15 carbon bikes and framesets. Built from carbon fiber for the stiffness and snappy handling the frame was designed around, and it ships with the Horst pivot bearings and middle spacers pre-installed for a cleaner, faster install.
Fitment
- S3-S4 frames only — sizes are frame-specific and not interchangeable
- 425mm seatstay length
- Mixed-wheel compatible: runs a 29" or 27.5" rear wheel
- 12 x 148mm Boost thru-axle spacing
Specifications
- Compatibility: 2025+ (MY25) Stumpjumper 15 Carbon
- Material: Carbon fiber
- Color: Gloss Black
- Includes: Horst pivot bearings and middle spacers
- Specialized part #: S245000009
UDH derailleur hanger and rear thru-axle are sold separately.
Why buy from Gravity Coalition
We're an authorized Specialized dealer with shops in Midway and Heber City. Not sure this is the right stay for your frame? Bring the bike in or call — our service team can confirm fitment and handle the install.
Specifications & Geometry
Full build details, sizing, and geometry