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Btwin 31.8 mm Seat Clamp

Sale price: $5.00 Regular price: $9.99

31.8 mm quick-release seat clamp.

Color: Select a color
Size: Select a size
Sale price: $5.00 Regular price: $9.99

Free shipping over $35

Final Sale: No returns or exchanges

See our return rules

Free pickup

San Francisco, 735 Market St. Options

Select an available color and size to see options.

Model: 3640340

Product Features

A photo of the Btwin 31.8 mm Seat Clamp in use

Btwin 31.8 mm Seat Clamp | tool-free fitting of your seat post onto your 29 mm frame or seat post.

31.8 mm quick-release seat clamp.


For 29 mm frames and seat posts.

Easy to use

No-tool adjustment/removal of seat post.


6061 aluminum and SCM435 steel seat clamp.


1.3 oz.

Product Customer Reviews

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218 Reviews
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Btwin 31.8 mm Seat Clamp,light grey
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MTB Seat Clamp

Does exactly what it is designed to do, at a very reasonable price

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Decent Clamp

Needed a replacement seat post clamp in a hurry, this is bulkier and heavier than I'd like, but it does the job and didn't cost the earth

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Good Quality Seat Tube Clamp from BTWIN.

I have purchased this as a replacement for the pre-fitted bad quality clamp on my bicycle which bent under pressure. This is a good one, functions smoothly as expected. I recommend this to others searching for a good quality clamp.

Hello Thang,

Thank you for sharing your valuable feedback. We are glad to know you like our product. Your review means a lot to us and lets us know we’re on the right track!



My problem has been solved my bike was fitted with allen screw which lost its thread on the very first adjustment, this product is the perfect replacement

Hi Amit,

Thank you for sharing your valuable feedback. We are glad to know you found the replacement part. We ensure to provide maximum replacement spare parts for our b-twin bikes. We are hopeful that you will continue to be satisfied with all our products and after-sale service.



Quality is Best and Durable, Great Fitting 👍🏼


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I am fully satisfied with the quality, fit and finish of the component.

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Worst buy ever

Not recommended to buy it cant hold ur seat

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Hello Hema chandra,

Thanks for taking the time out to give us your feedback.

We regret that you weren't satisfied with our product.

If i understand right, the seat-post isn't is slipping, you could try tightening the other side of the clamp and this will surely help as the hold would get better.

If I've misunderstood the issue, we would love to help solve the problem for you, and hence i request you to visit your closest store and our team will be more than happy to help.

Thank you!

Happy Riding


durable..does its job

Good one

No issues so far

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Successful replacement for Riverside 100 clamp

My Riverside bike is used by my daughter too. For that I always had to carry my Allen key. Now this one is easy to operate to adjust height accordingly.

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Solid and easy to use

Can adjust our saddle without any tool.

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seat post clamp

The tightening nut is too small. Need a bigger one for better grip.

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erfüllt seinen Zweck

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Schnellspanner für Fahrradsattel

Super Produkt, wir sind sehr zufrieden

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Additional Product Information



  • 100% Aluminum



Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

Decathlon makes the difference
  1. product-research

    Research and development

    delivers high-quality cost-effective products

  2. State-of-the-art production processes

    minimize manufacturing costs

  3. Optimized supply chain

    reduces retail prices

  4. laptop-checkout

    Minimal retail footprint

    lowers overhead and indirect costs


Size Guide Visual