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The Bontrager Carbon-Friendly Quick-Release Seatpost Clamp is a 36.4mm seat tube clamp designed for Trek and other bikes with a 36.4mm seat tube internal diameter — the standard seat tube size used on most Trek road and gravel frames. The carbon-friendly designation means the clamp uses a design that distributes clamping force evenly around the seatpost, avoiding the point loading that can damage carbon seatposts when standard clamps are overtightened. The quick-release lever allows tool-free seat height adjustment without needing a hex key, making it practical for riders who regularly adjust saddle height between rides or share a bike.
The clamp is a genuine Bontrager part, making it the correct OEM replacement for Trek bikes originally fitted with this clamp. It fits any seatpost with a 36.4mm outer diameter — verify your seatpost diameter before purchasing, as seatpost clamp size is determined by the seat tube's internal diameter, not the seatpost's outer diameter. Browse our full seatposts collection and finishing kit range for seatposts, saddles, and related components.
How do I know if 36.4mm is the correct size for my bike?
The seatpost clamp size matches the internal diameter of your frame's seat tube. Most Trek road and gravel frames use a 36.4mm seat tube. Check your frame's specification on the Trek website using your model and year, or measure the internal diameter of the seat tube opening. The clamp size is often also printed on the existing clamp.
What does "carbon-friendly" mean?
Carbon-friendly clamps distribute clamping force evenly around the circumference of the seatpost rather than concentrating it at a single point. Standard clamps can create point loading when tightened, which can crack or delaminate carbon seatposts over time. Always tighten to the torque specified by the seatpost manufacturer regardless of clamp type.
Can I use this with a dropper seatpost?
No — dropper seatposts require a clamp that accommodates the remote cable or hydraulic hose routing from the post. A standard quick-release clamp will not provide the correct cable routing and may interfere with dropper post operation.
Is a quick-release clamp as secure as a bolt-type clamp?
For road and gravel use, a correctly adjusted quick-release clamp provides secure and reliable seatpost retention. For aggressive MTB use where the saddle is subject to significant lateral forces, a bolt-type clamp provides more consistent clamping force and is generally preferred.
Stock Status Instock - Instore - Item Usually shipped or available for shop collection, within 48 hours (Mon-Fri)
Instock - Supplier Warehouse - Item is held in Suppliers Warehouse, Depending on the the supplier transfer time can vary from 24 Hours to 14 Days for item held in European warehouse.
(over festive periods some suppliers shut from 24th Dec-2nd Jan so orders can be delayed through this period.)
Brands held in European website include Trek, Bontrager, Electra, Wahoo, Rapha. For up-to-date transfer times please call customer services on +44 (0)1782 768622
Most out products are shipped by FedEx, providing unprecedented reliability and speed. Lightweight Spares below £25.00 value have a Royal Mail postage option, which is sent via Tracked 48 service. - £2.99
Shipping on all Domestic Orders over £50.00 (excluding bikes and home trainers) for delivery within the UK is completely FREE!
Bike and Home Trainers and oversize Goods £15.00 - FedEx
White Glove Bike Delivery - our white glove option has your bike personally delivered to you by a fully trained Mechanic and Bike fitter - £99.99
(Certain bikes will only have this option such as Cargo Bikes)
To Qualify for FREE Shipping:
In some cases, we may ship items out with another courier, depending on the status and availability of items ordered. (Customers will not be charged more and will be refunded any unused postage cost) If part of an order is cancelled and the total drops below the £50.00 free postage, a postage charge may be taken.
Delivery costs will be clearly stated on the checkout page, though you will need to register (to provide your delivery address) in order to see the delivery costs.
If you have any questions about delivery charges, times or none delivery please do not hesitate to get in touch by email:store@swinnertoncycles.co.uk or by telephone on +44 (0)1782 768622. Handling is normally 48 hours, but at busy periods this may be extended but we will endeavor to process your order within 5 working days. Please bear in mind in some cases orders can take longer to process, please contact us for more details.
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

