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  1. #1
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    Skinny tube in fat tire idea?

    Blame it on all the codeine I'm taking, but what if you lined the inside of a fat tire with something like a layer of sill foam before using a narrow tube? The tube wouldn't have to expand as much to fill the void, and the foam has almost no weight. Or, is it just the narcotics talking to me?

  2. #2
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    I don't know. Might squish the foam to nothing.
    No issues running 2.4 or 2.5 (can't remember) q tubes. Probably no need to worry. I'm running tubeless on my second fat bike. Love it.

  3. #3
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    Probably make the tyre feel dead.

    Maybe if it was used as a rim strip so the tube was directly in contact with the tyre.
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  4. #4
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    Its interesting, in motocross bikes they were using foam at one point. Might be something to look into.

    In RC cars they began to use foam in the tires as well.

  5. #5
    ouch....
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    I used that type of foam as a liner for split tube method tubeless. after a few months I swapped tires and had a look inside, foam was squished flat.
    Riding.....

  6. #6
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    I used to put hoagie buns in my tires. That worked pretty well. I never looked inside after but I imagined the hoagie buns were mostly intact.

  7. #7
    Harmonius Wrench
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    Tubes "scrub" as they deform on the trail surface on the inner carcass of the tire. If there were a layer of foam there, it likely would get scrubbed to bits which may chafe the tube to the point of failure. Proper materials would need to be found to make that work. I would think it also would be detrimental to the trail feel and rolling resistance would also spike, since that foam is a deterrent to the tire's conforming to obstacles on the ground.

    No sir, I do not like it!

  8. #8
    Chad
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    Not that I'd do it,...... but if you drilled an opposing valve hole and installed 2 ultra light Maxis mtb tubes and inflate equally. At 48 grams each you trim some serious weight.

  9. #9
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    That seems like a cool idea. I've been following Wadester's beadlock thread, and it looks really close to fruition, but the weight scares me. Two light tubes side by side with some sort of limiting strap over them, like a 100 mm x 29er-sized rim strip made from PVC would allow the tubes to seat the beads but not expand into the tire cavity too much.

  10. #10
    Dr Gadget is IN
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    Yeah, wadester's got too many projects on the fire - but it's getting close.

    Dirtbikers use "bib mousse", which is "a ring of flexible foam that is placed inside a tire before it is fitted on the rim". The equivalent of those foam inserts you could buy at Wallymart for bicycles. It has always seemed that a foam thick/sturdy enough for a reasonable "pressure equivalent" was also heavy. Light foams don't have enough strength to support the load (as noted above) and are smashed flat.

    Inner tubes will expand to fill the space inside the tire, or rip open if they don't. I note that the PVC rimstrips that come with clownshoes bubble up in the windows. More pressure will equal bigger bubble until they come apart.
    Fatbikes are much more fun than they should be allowed to be!

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  11. #11
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    Quote Originally Posted by deuxdiesel View Post
    Blame it on all the codeine I'm taking, but what if you lined the inside of a fat tire with something like a layer of sill foam before using a narrow tube? The tube wouldn't have to expand as much to fill the void, and the foam has almost no weight. Or, is it just the narcotics talking to me?
    It won't work the way you think it will. Will be lighter but the deformation that fat tires are known for will be compromised. In other words, it will ride like s#it!

  12. #12
    Ride da mOOn Moderator
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    Wink

    2 words "Pop Nots"

    Used to sell under that name a piece of pipe insulation that wrapped the tube to prevent pinch flats had them in once took them out and they were so flat you could see through them.

    Just put in 3 regular tubes in LOL

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