Specialized Stumpjumper 15 Bolt On Rear Thru-Axle Description: This Specialized Stumpjumper 15 Bolt On Rear Thru-Axle works to replace worn or broken thru-axles found on select Specialized Stumpjumper models. Specially designed for maximum stiffness, this thru-axle features a non-tapared mid-section that is fastened within rear dropouts via a 6mm hex head. Features: Replacement thru-axle for Specialized Stumpjumper bikes 6mm hex head OEM replacement part on the following bikes: 2025 S-Works Stumpjumper 15 2025 S-Works Stumpjumper 15 Frameset 2025 Stumpjumper 15 Comp 2025 Stumpjumper 15 Expert 2025 Stumpjumper 15 Pro 2025 Stumpjumper 15 Ohlins Coil