Free 2-Day Shipping on Orders Over $50

Detail Images

  • Thomson - Side
  • Thomson - Front
  • Thomson - Top
  • Thomson - Case/Package
  • Thomson - Seatpost Collar - Black
  • Thomson - Seatpost Collar - Silver
  • Thomson - Side -
  • Thomson - Front -
  • Thomson - Top -
  • Thomson - Case/Package -

Current Color

  • Thomson - Seatpost Collar - Black
  • Thomson - Seatpost Collar - Silver

Thomson Seatpost Collar


Free 2-Day shipping on orders over $50. Learn More

Select style & size:

Select options
  • Select options
    • Black, 28.6mm
    • Black, 31.8mm
    • Black, 35mm
    • Silver, 28.6mm
    • Silver, 31.8mm
    • Silver, 35mm
    • Black, 36.4mm
    • Silver, 36.4mm

    13 Reviews


    Functional bling for your cockpit.

    Most riders don't consider their seatpost collar on day-to-day rides—until their seatpost starts to creep down halfway through some epic ride due to a poorly constructed collar. The Thomson Seatpost Collar not only alleviates your underperforming seatpost collar woes with its powerful clamping force, but it also adds serious bling to your cockpit with its anodized black or shiny silver finish.

    • Aluminum with anodized black or silver finish
    • 1.5-degree off-center threaded bolt
    • 18-gram weight
    • Item #THP0008

    Tech Specs

    Claimed Weight
    18 g
    Recommended Use
    road cycling
    Manufacturer Warranty
    5 years

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Elegant and Simple

    • Familiarity: I've put it through the wringer

    I have used Thompson on a few of my bikes, Surly Cross Check, Wife's Surly Troll and my new TI 29+. Thomson has done nothing but impress, don't think twice upgrade your components.

    Elegant and Simple

    Much better than any stock clamp

      This and the Salsa clamp are both great performers. Broke the factory clamp on my 2016 Cannondale Supersix. Had a Thompson 28.6 clamp in my toolbox. Even though the dia. spec is a little different the Thompson is holding my post just fine. Going to order another as a spare.

      Us made brilliance

        A seatpost clamp may not be the first thing you may think of to upgrade on your bike, but if you're running a Thomson stem and post, might as well go all out! It comes with a tiny 3mm hex head bolt, but the design of this will keep your post secure.

        Us made brilliance

        Thomson....Nuff said

        • Familiarity: I've put it through the wringer

        I rock Thomson stems and seat post on all my bikes. This is the first time using their seat collar. As all of their other products it has beautiful craftsmanship. Just can't go any better for performance and price.

        Solid Clamp

        • Familiarity: I've used it once or twice and have initial impressions

        I'm amazed at the low torque needed to get such a solid hold. I'm guessing this will lessen the chances of ever having to replace it. The last clamp I had popped at 5nm torque. The threads pulled out of the clamp body. This Thomson clamp specs only 2.8nm torque, and it is holding really strong! This is a great seatpost clamp!

        It's the little things...

        • Familiarity: I've used it several times

        Seat collars are simple and only have one job-keep your post from slipping. It is surprising how often something as simple as a seat collar is done badly. Either the collars don't keep the post in place or the collar itself is susceptible to breakage.

        The Thomson collar will not let you down. It is light, it is dependable and elegant. I would say that this simple collar design and finish boards on usable art.

        Upgrade your bike now!

        That added bling

        • Familiarity: I've put it through the wringer

        Thomson Post?-Check

        Thomson Stem? Check

        Thomson Bars?-(YEP they make bars!) Check

        Thomson Seat Collar?- NO?!?! What is this, amateur hour? Add that added bit of bling, you know you want to, your bike will thank you.

        Solid piece, set it and forget it

          Would have given this a 5 if it was a little lighter or a little more economical.

          Lets be honest, the only reason 95% of us upgrade from stock is to save weight or add bling. This part is anti-bling but lighter than your average QR factory clamp, but I replaced it on my latest build with a titanium unit weighing 10g that was half the price, so.....

          is the measurement referring to the inside...

          is the measurement referring to the inside diameter? my bike seat tube is 31.8 internally so the seat post clamp should be the larger diameter?

          Unanswered Question

          If my frames seatpost size is 27.2mm ,what...

          If my frames seatpost size is 27.2mm ,what would be the normal clamp tube size?

          I need a clamp for a 63CM Serotta (road...

          I need a clamp for a 63CM Serotta (road bike) w/ a Ti frame - 31.8. I’m using a Thompson 30.9 seatpost, will this fit the fame and clamp down the post?

          Is there a return policy?

          Hey Doug. I don't think the 31.8 will fit your bike. I think you need a 34mm but you could measure the outside diameter of your seat tube if you have calipers and it will give you a number close to what size you will need. Bear in mind we are work in very small increments so you will need to be precise. Aluminum frames with 31.6 seatposts usually run the 35mm clamp but since you have a Ti frame and a 30.9 seatpost you are going to need something in the 44mm range.