Specialized Tarmac SL8 Di2 Battery Seatpost Mount Internal OEM

Specialized Internal Shimano Di2 Battery Seatpost Mounting Kit – Tarmac SL8

This Specialized factory replacement internal Di2 battery mounting kit is engineered specifically for Tarmac SL8 carbon seatposts. It securely positions the Shimano internal Di2 battery inside the seatpost, preventing movement, eliminating rattle, and protecting the battery from vibration—all while maintaining a clean, race-ready appearance.

Designed to OEM specifications, this is the correct solution for Di2-equipped SL8 builds, framesets, and service replacements.

Features & Benefits

• Genuine Specialized OEM replacement part
• Designed exclusively for Tarmac SL8 carbon seatposts
• Securely holds Shimano internal Di2 batteries
• Eliminates internal battery rattle and vibration
• Lightweight plastic construction
• Fully hidden internal installation for clean aesthetics

Product Details

• Application: Internal Shimano Di2 battery mounting
• Seatpost compatibility: Tarmac SL8 carbon seatposts only
• Material: Plastic
• Installation location: Inside seatpost
• Quantity: 1 mounting kit

Battery Compatibility

Compatible with Shimano internal Di2 batteries:

• BT-DN110
• BT-DN300

OEM Compatibility2026

• Tarmac SL8 Pro – Shimano Ultegra Di2
• Tarmac SL8 Expert – Shimano Ultegra Di2
• Tarmac SL8 Comp – Shimano 105 Di2
• Tarmac SL8 Frameset – FACT 10r Carbon
• S-Works Tarmac SL8 – Shimano Dura-Ace Di2
• S-Works Tarmac SL8 Frameset – FACT 12r Carbon
• S-Works Tarmac SL8 Frameset LTD – Demi Dreaming
• S-Works Tarmac SL8 LTD – Red Bull 2025 TdF

2025

• Tarmac SL8 Pro – Shimano Ultegra Di2
• Tarmac SL8 Expert – Shimano Ultegra Di2
• Tarmac SL8 Frameset – FACT 10r Carbon
• All S-Works Tarmac SL8 variants (LTD, Team, Frameset, Complete)

2024

• Tarmac SL8 Pro – Shimano Ultegra Di2
• Tarmac SL8 Frameset – FACT 10r Carbon
• S-Works Tarmac SL8 (Framesets & Complete models)

Seatpost Reference

• 2023 S-Works Tarmac SL8 Carbon Seatpost

Installation Notes

• Seatpost removal required for installation
• Compatible only with Tarmac SL8 carbon seatposts
• Not compatible with Pavé, Alpinist, SL7, or SL6 seatposts

Why Use the OEM Mount?

Using the correct Specialized internal battery mount ensures:

• Silent operation (no battery rattle)
• Proper battery positioning and protection
• Factory-correct integration
• Long-term reliability and clean internal routing

A genuine Specialized OEM solution for securely mounting Shimano Di2 batteries inside Tarmac SL8 seatposts—essential for professional builds, service replacements, and maintaining factory-level performance.