TPU inner tube problem
#26
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You are more likely to pinch a tube that is partial inflated because you are more likely to have to use tools to install the tire. I don’t pinch tubes and I never inflate tubes. I assure you that I know what I am doing.
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#27
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The relevant property here, is that TPU tubes don't UN-stretch as much as butyl after you've over-inflated them. So they're always a little more difficult to install, doubly so when you've stretched them. Good news is they're pretty tough so even if you pinch or fold it going in, it'll still probably work at least as a spare... might be lumpy.
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The problem is that the TPU tube likes to cling to the inner wall of the tire. So when you get to the last part, you will find that the TPU tube is just under the tire bead. Prying the tire bead at this point would pinch the tube. That is why you need to inflate the TPU tube to get it to stay in the main body of the tire and away from the bead area.
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We're talking about a few psi. This will not make the tire harder to manipulate and needing to therefore use tools you wouldn't need otherwise. Partially inflating the tube this tiny bit, also actually gets it out of the way of the beads and up under the interior tread part of the tire. Instead of having a floppy deflated mess which is more easy to get a tiny bit falling under a part of the bead/rim interface.
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You certainly couldn’t tell that from your tube installation technique. Carry on.
Last edited by smd4; 04-23-24 at 06:48 AM.
#31
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The problem is that the TPU tube likes to cling to the inner wall of the tire. So when you get to the last part, you will find that the TPU tube is just under the tire bead. Prying the tire bead at this point would pinch the tube. That is why you need to inflate the TPU tube to get it to stay in the main body of the tire and away from the bead area.
We're talking about a few psi. This will not make the tire harder to manipulate and needing to therefore use tools you wouldn't need otherwise. Partially inflating the tube this tiny bit, also actually gets it out of the way of the beads and up under the interior tread part of the tire. Instead of having a floppy deflated mess which is more easy to get a tiny bit falling under a part of the bead/rim interface.
I will carry on installing flat tubes like I have been for the last 40 years. Trying to put tires on an inflated tube is just as difficult as trying to take a tire off an inflated tube.
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#32
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Utter nonsense, of course. Not difficult at all. No tools necessary. Again, carry on.
Last edited by smd4; 04-23-24 at 07:36 PM.
#33
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Haven’t installed any modern tires lately?
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#34
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Has it ever occurred to you two experts that there might be more than one way to successfully mount a tubed tire?
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#37
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If you have to inflate the tube prior to installation, put it in the tire first. That will constrain the tube to keep it from expanding too much. Every pressure vessel elongates as well as expands under pressure. Tubes just happen to be very weak pressure vessels that aren’t meant to be inflated outside of a stronger pressure vessel.
A rubber tube would expand and elongate much more than a TPU tube which isn’t very stretchy at all, contrary to what has been written above. The instructions on the TPU tubes say not to inflate them too much outside of the tire or the tube will be damaged.
Frankly, there is no need to inflate the TPU or any other kind of tube upon install. A tire that is tough to install will be harder to install with air in the tube. Just put the tube in the tire and mount the tire.
A rubber tube would expand and elongate much more than a TPU tube which isn’t very stretchy at all, contrary to what has been written above. The instructions on the TPU tubes say not to inflate them too much outside of the tire or the tube will be damaged.
Frankly, there is no need to inflate the TPU or any other kind of tube upon install. A tire that is tough to install will be harder to install with air in the tube. Just put the tube in the tire and mount the tire.
Based on this thread, I mounted one with as much air as I could do with my mouth, and another with no air.
Both went on ok. Kind of a pain, it definitely feels like mounting a grocery bag inside the tire. Thin. I would advocate for what your comfortable with and to go out of your way to do it without levers if possible.
Oddly enough, neither tire rolled evenly after inflation. I think with the less stretch in the tube, it doesn’t pop them into place. I got mine a lot better by manipulating the bead under about 3-4psi. I’ll revisit it later with some soapy water on the bead. That’ll fix it.
Funny thing about them, based on mounting them and fiddling with them, the spare in my saddle bag is butyl.
Im seriously questioning my other TPU tubes as spares, I just can’t really see a scenario where tubeless fails me that these would get me home. I’ll keep my sealant topped off and my plugs loaded.
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I can understand that my question probably sounds very stupid. This is not the first tube I've installed 🤣But reading the instructions tubes must be inflated a bit before installed.Now take a look at those images 1- 2- Those are two different tubes inflated just a bit for the installation itself.One is completely flat against the rim and the tyre installation can be done easily.The other one is almost impossible since the tube folds on itself making it impossible to install correctly without pinching. Note that both tubes are newer, fresh from package.
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#39
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I have seen folks give a quick blow with their mouths to minimally inflate a tube to install.
Butyl tubes will do as your picture shows also, because there is no restriction. When the tire is on, the tube is confined. More air at a constant volume means greater pressure.
I am thinking of converting to TPU tubes...when I use up my inventory of conti butyl, which now stands at 4. At the current rate, that will be in 2028.
Butyl tubes will do as your picture shows also, because there is no restriction. When the tire is on, the tube is confined. More air at a constant volume means greater pressure.
I am thinking of converting to TPU tubes...when I use up my inventory of conti butyl, which now stands at 4. At the current rate, that will be in 2028.
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