Introducing Mr. Fusion

After over a year in design, testing and production, it FINALLY lives!

Mr. Fusion is our new modular, user-friendly, and stupidly-stable seat system.


Mr. Fusion

Mr. Fusion loaded


The heart of the system lies in the integration of a lightweight support hoop, and a dedicated seatpost clamp.  This support hoop system creates an incredibly solid connection to the bike, and reduces all sway in the pack, even when loaded with the most massive of loads.   The support hoops and clamps are all custom manufactured for Porcelain Rocket by our friends at Hunter Cycles in California.

The pack insert is derived from our popular Booster Rocket seatpack, in size and shape.  With a 5-14L capacity, this pack is perfect for stowing a shelter, food, sleep system, clothing or whatever you can dream up.   The pack inserts will be available in black, grey and red 500 denier Cordura, or any custom colour (with a custom lead time).

System Highlights :

– 14 oz. complete, including support hoop, clamp, system harness and pack insert.

– 5 to 14 liters of volume with the included pack insert.

– 4130 Chromoly support hoop built custom by Hunter Cycles in Bonny Doon, California.  Powdercoated Black.

– Dedicated aluminum seatpost clamp available in 27.2mm, 30.9mm, or 31.6mm.

– Built with 500D Cordura, Dimension Polyant VX fabrics, 0.75″ & 1″ nylon webbing, and bomber Duraflex hardware.

– High stitch count bartacks at each and EVERY stress point.

– Hypalon-reinforced points of contact with the bike.

– Obsessive attention to detail and quality (as always).


Mr. Fusion unloaded

Mr. Fusion unloaded


Mr. Fusion will retail for $170 CAD, including the pack insert and will be available in the webstore mid-September.

Also, stay tuned for a video description of the new system in the coming weeks.

Thanks as always for the AMAZING support!



  1. Vik says:

    I’d like to order one of these. I saw a prototype in action and it worked amazingly well.

    — Vik

    • theporcelainrocket says:

      You got it, Vik!

  2. Doug D says:

    After using the prototype for several months, I have to comment on how awesome this new system is. The best thing about it is the way that it is rock steady when riding, even when ridiculously loaded.
    I also love how the modularity allows me to easily pull the bag off to bring it into my tent or a store while still having the on-bike stability that everyone craves.
    I also love how refined the released iteration is after all the prototype testing.
    It is no stretch to say that this is my favourite bike bag.

    • theporcelainrocket says:

      Thanks Doug!

  3. Wayne says:

    Scott, how much seat post is needed for the rack and bag to fit?

    • theporcelainrocket says:

      Hey Wayne! Mr. Fusion requires about 6″ (150mm) of exposed seatpost.

      • Wayne says:

        Oh no, that’s what I thought from the photos. I have only 10 cm (4″) of space. Looks like the Sally Ride will continue to be my go-to saddle bag.

        • theporcelainrocket says:

          We could easily talk about a lower profile pack insert, so that it works with your shorter seatpost allowance.

  4. Tim Durack says:

    Thudbuster LT compatible? (Looks awesome by the way.)

    • theporcelainrocket says:

      Good question! Making a Thudbuster LT compatible pack insert would be fairly simple, but it would be a custom option.

      • abroad says:

        how abou with t a short travel thudbuster?

        • theporcelainrocket says:

          This version of Mr. Fusion should work just fine with a Thudbuster ST.

      • Dave Morgan says:

        You’ve got me intrigued: As far as I can tell from your photos, Mr Fusion attaches to the seat post and to the saddle. With the Thudbuster, and saddle position moving relative to the seat post, how does that work?

        • theporcelainrocket says:

          Hey Dave,

          At the moment, we are not recommending Mr. Fusion to be used with a Thudbuster. However, we are working on a Thud-able version.


  5. Kent Fackenthall says:

    You had me at ‘Mr.’ I’m in.

  6. Colin says:

    Does this system work with any dry bag? If not is there one coming?

    • theporcelainrocket says:

      We are working on a V2 that will allow folks to use any commercial drybag (or mini-kegs). Stay tuned in the coming months.

  7. Tom Walwyn says:

    Sarah wants to know whether the removable bag is waterproof?

    • Tom Walwyn says:

      So do I! I presume it would work (less well) with a different dry bag as the back strap would tension it into the set-up…

    • theporcelainrocket says:

      No, but see the comment above. 😉

  8. Cass says:

    I’ve been mistreating a proto version for the last few months in South America. Massive thumbs up!

    The new production version looks super slick. Nice one Scott.

  9. Tony says:

    I just spent the summer on GDMBT with one of these. Well, similar since it was not a production model. Worked great only disappointment was it didn’t improve my ability to pedal my bike faster. Haha. Now I want one of the new shiney ones. Great system. Stays put and brilliantly made. I think I sold a few along the way 🙂

  10. Toni Lund says:

    Looks absolutely fantastic and definitely I would like to have one!

  11. Sam H says:

    Great to read this is officially seeing the light of day. A very cool advancement in bikepacking tech, Scott.

  12. Frank says:


    Looks awesome! I’ll take 2 of the frames and one bag please and thanks.

    However … is there another way to secure it to the seat post than velcro? (Velcro wears out eventually is all)

    Thanks. Frank

    • theporcelainrocket says:

      Hi Frank,

      Will you email me through the CONTACT page on the site?

      The seatpost attachment will stay Velcro for now.


  13. Todd Schulke says:

    Do you see any reason that the PR seatpost collar couldn’t be replaced with this Salsa seat post Rack-Lock ( That would give me 6″ of space for your bag and use one collar for both. Might not work with more seat post exposure.

    • theporcelainrocket says:

      Hey Todd,

      Yes, this will work very well. If you have exactly 6″ of exposed seatpost, then this is the cleanest way to mount Mr. Fusion. The reason we have developed a dedicated clamp, is because everyone has a different amount of exposed post.


      • Todd Schulke says:

        Another way to think about this is that the Salsa Rack-Lock will work with a bag 6″ or smaller in depth but smaller than 6″ requires a custom bag insert. Is this right?
        I’m really interested in V2 so I can use a dry bag.

  14. Anne says:

    Cool design.

    How much room between saddle and wheel do you need? I ride a Surly Krampus, so I have way more than 6″ of exposed seatpost. But I can’t tell if there would be room for the bag, or if it would hit those big tires on my bike.

    • theporcelainrocket says:

      Hi Anne,

      Mr. Fusion requires about 7.5″ of space between the seat rails and tire. We are working on a Mr. Fusion Mini currently.


  15. Erik says:

    Works like a charm and you have no idea that it is back there. Thanks my friend.

  16. Charley says:

    Looks like a great setup! How well does this compress if it’s only half full? Is all of the compression in the support hoop system or is there some in the bag too? Final question: any videos available of this system in action?


    • theporcelainrocket says:

      Hey Charley,

      Given that the system does not rely on compression for stability, all works well when only half-full. The bag insert closes like a drybag and can be packed off the bike, so you can compress fairly well. There is also a complete compression strap that goes over the back side of the entire system. You can see it in the photo of the system when empty. We are working on videos for all of our new designs.


  17. Tom Knipper says:

    Any issues with Mr. Fusion and a Ti Salsa seatpost?

    • theporcelainrocket says:

      Hey Tom,

      The Mr. Fusion clamp isn’t really clamped all that hard to the post (or it shouldn’t be!), so it should be fine with Ti posts.


  18. shlomi says:

    hi ,
    reg. Mr. Fusion : i have 2 bikes . one with 27.2 and one 31.6 seatpost . is there and ” adaptor ” which can allow me to us one clamp on those 2 bikes/ seatpost ?
    thank you

    • theporcelainrocket says:


      No, at the moment, we are only offering clamps in the three specific sizes of today’s most common seatpost sizes. We can supply you with extra clamps, no problem.


  19. simon cross says:

    Hey Scott
    Received MR FUSION DOWN in Australia – only to bring it back this year for a run down the GDMBR Tour Divide.

    Very Happy, took it on a bumpy test ride with some new single track – did not budge or move at all.


    DO you suggest for very wet days using a garbage liner or will the seat bag alone be up to long term all day rain?

    Also what NM or InLBS torque would you suggest on the clamp for on a Thomson seat post (AL)

    I take it the compression brace straps go over the saddle rails – that is how i have been testing.. that right

    Cheers – have fun when you head back to Australia



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