Speed Saddle Clamp 34.9Mm Alloy Qr

 Speed Saddle Clamp 34.9mm Alloy QR (Quick Release)

The Speed Saddle Clamp 34.9mm Alloy QR is a seatpost collar (also called a seat clamp) used to secure a bicycle’s seatpost inside the frame’s seat tube while allowing quick, tool-free adjustment.

⚙️ Key Specifications

• Diameter: 34.9 mm (fits a 34.9 mm outer seat tube)
• Material: Aluminium alloy (lightweight and corrosion-resistant)
• Mechanism: Quick release (QR) lever
• Function: Locks the seatpost height in place

 Compatibility

Typically used on:

• Modern aluminium frames
• Some carbon frames with metal inserts
• Mountain bikes (MTB)
• Hybrid and commuter bikes
• BMX race or freestyle bikes with larger seat tubes

Important:
The 34.9 mm size refers to the frame seat tube outer diameter, not the seatpost itself. The seatpost is usually smaller (e.g., 27.2 mm or 31.6 mm), depending on the frame.

⚡ Advantages

• ???? Tool-free adjustment (quick height changes)
• ⚖️ Lightweight alloy construction
• ???? Convenient for shared or adjustable bikes
• ???? Secure clamping when properly tightened
• ???? Easy to replace or upgrade

⚠️ Limitations

• QR levers can loosen if low-quality or poorly adjusted
• Over-tightening can damage lightweight frames (especially carbon)
• Must match exact frame diameter—34.9 mm is not universal

 Bottom line

Yes—this is a quick-release seat clamp used to lock a 34.9 mm seat tube, mainly on modern bikes where fast saddle height adjustment is useful.