A Secure 39.7mm Clamp with a Clean Burgtec Finish.
The Burgtec 39.7mm Seat Clamp is a lightweight replacement or colour upgrade for compatible mountain bike frames. Made from 6061-T6 aluminium with corrosion-resistant stainless-steel hardware, it keeps the seatpost securely positioned without adding unnecessary bulk.
The 39.7mm size is found predominantly on selected Trek full-suspension frames, but it should not be ordered by bike brand alone. Check the size marked on the original clamp or measure the outside diameter of the frame before ordering.
Check the Clamp Diameter
The stated 39.7mm measurement refers to the outside diameter of the frame’s seat tube where the clamp fits. It does not refer to the diameter of the seatpost itself.
A bike with a 34.9mm seatpost may still require a larger frame clamp, depending on the wall thickness and construction of the frame. Do not assume the required clamp size from the seatpost diameter.
Dropper-Friendly Installation
The opening at the rear of the clamp is wide enough to make installation easier around many internally routed dropper-post cables. Depending on the frame and cable routing, this may allow the clamp to be changed without disconnecting the dropper cable.
Always check the routing before removing the original clamp and avoid pulling or twisting the cable unnecessarily.
6061-T6 Aluminium Construction
The clamp is made from 6061-T6 aluminium for a useful balance of strength, durability and low weight. Smooth edges and a minimal shape give it a tidy appearance that works particularly well alongside other Burgtec finishing parts.
A corrosion-resistant stainless-steel bolt provides dependable clamping through regular riding and wet conditions.
Key Features
- 39.7mm seat-clamp diameter
- Designed for compatible mountain bike frames
- Used predominantly on selected Trek full-suspension bikes
- 6061-T6 aluminium construction
- Corrosion-resistant stainless-steel hardware
- Wide rear opening assists with dropper-cable installation
- Smooth, low-profile shape
- Available in nine Burgtec colours
- Approximate weight of 22g
Our Thoughts
This is a straightforward way to replace a damaged clamp or add a small colour detail to the bike. It is light, neatly finished and available in the same colours as many Burgtec pedals, stems, grips and chainrings.
The important part is getting the diameter right. Although Burgtec identifies 39.7mm as a size used predominantly on Trek full-suspension bikes, it does not fit every Trek. Check the original clamp or measure the frame before ordering.
When fitting the clamp, use the torque specified by the frame or seatpost manufacturer. Excessive tightening can damage a frame or seatpost and may prevent a dropper post from moving freely.
Why Buy from Chain Reaction?
- Help confirming the correct seat-clamp diameter
- Professional seatpost and dropper-post installation available
- Independent Christchurch bike shop
- Nationwide New Zealand delivery
Specifications
- Brand: Burgtec
- Product type: Seat clamp
- Clamp diameter: 39.7mm
- Material: 6061-T6 aluminium
- Hardware: Stainless steel
- Weight: Approximately 22g
- Available colours: Burgtec Black, Race Red, Deep Blue, Purple Rain, Kash Bronze, Iron Bro Orange, Rhodium Silver, Burgtec Bullion Gold and Toxic Barbie Pink
- Intended use: Compatible mountain bike frames
