BBSwapFinder

index / standards / record

What seatpost diameter does a Specialized Stumpjumper (2019 on carbon) use?

The seatpost fitment standard on a Specialized Stumpjumper (2019 on carbon), and how to pick the right part.

DROPS IN
A Specialized Stumpjumper (2019 on carbon) uses a 34.9 mm class seatpost interface.
This frame's fitment
FrameSpecialized Stumpjumper (2019 on carbon)
Seatpost diameter34.9 mm
Diameter34.9 mm
Typical classmodern trail and enduro mountain frames wanting the largest, stiffest dropper interface

The carbon Specialized Stumpjumper uses a ZS44 upper zero-stack headset, a 34.9 mm dropper seatpost, a 15x110 Boost front thru-axle and a braze-on front-derailleur mount if a front mech is fitted.

Most builds are 1x with no front derailleur; the mount note applies only to 2x conversions. The bottom bracket is a 73 mm BSA threaded shell, covered on its own page.

The part to buy
Search Amazon for 34.9 mm seatpost for your Specialized Stumpjumper (2019 on carbon)affiliate searchFind 34.9 mm seatpost for your Specialized Stumpjumper (2019 on carbon) on eBayaffiliate
Related fitment pages
34.9 mm seatpost34.9 mmBottom bracket for Specialized Stumpjumper (2019 on carbon)same frame, BB shellHeadset on a Specialized Stumpjumper (2019 on carbon)same frame34.9 mm seatpost on a Santa Cruz Hightowersame standard, another frame

SOURCES: BikeGremlin, Seatpost diameter sizes (standards) · BikeRadar, Bike seatposts explained: diameters, materials, lengths · Park Tool, Standardized Headset Identification System (SHIS) · BikeRadar, Mountain bike axle standards: the complete guide