TPU inner tube problem
04-22-24, 09:02 PM
#26
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,384
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6228 Post(s)
Liked 4,231 Times
in
2,373 Posts
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.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
04-22-24, 09:25 PM
#27
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,384
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6228 Post(s)
Liked 4,231 Times
in
2,373 Posts
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.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
04-22-24, 11:34 PM
#28
Senior Member
Join Date: Aug 2009
Posts: 2,408
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 1,745 Times
in
980 Posts
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.
Likes For icemilkcoffee:
04-23-24, 05:10 AM
#29
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,656
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4756 Post(s)
Liked 1,537 Times
in
1,006 Posts
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.
Likes For Sy Reene:
04-23-24, 05:13 AM
#30
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,857
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3553 Post(s)
Liked 2,969 Times
in
1,798 Posts
You certainly couldn’t tell that from your tube installation technique. Carry on.
Last edited by smd4; 04-23-24 at 06:48 AM.
04-23-24, 07:27 PM
#31
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,384
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6228 Post(s)
Liked 4,231 Times
in
2,373 Posts
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.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
04-23-24, 07:30 PM
#32
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,857
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3553 Post(s)
Liked 2,969 Times
in
1,798 Posts
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.
04-23-24, 07:36 PM
#33
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,384
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6228 Post(s)
Liked 4,231 Times
in
2,373 Posts
Haven’t installed any modern tires lately?
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
04-23-24, 07:37 PM
#34
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,857
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3553 Post(s)
Liked 2,969 Times
in
1,798 Posts
04-23-24, 07:37 PM
#35
Senior Member
Join Date: Sep 2017
Posts: 7,964
Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 7043 Post(s)
Liked 11,088 Times
in
4,737 Posts
Has it ever occurred to you two experts that there might be more than one way to successfully mount a tubed tire?
Likes For Koyote:
04-23-24, 07:39 PM
#36
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,857
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3553 Post(s)
Liked 2,969 Times
in
1,798 Posts
05-01-24, 02:23 PM
#37
With a mighty wind
Join Date: May 2015
Posts: 2,612
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1105 Post(s)
Liked 894 Times
in
501 Posts
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.
Likes For rosefarts:
05-02-24, 12:40 AM
#38
Senior Member
Join Date: Apr 2007
Posts: 6,794
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1116 Post(s)
Liked 1,212 Times
in
769 Posts
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.
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.
Likes For Camilo:
05-02-24, 06:58 AM
#39
Senior Member
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.
05-04-24, 10:19 AM
#40
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,857
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3553 Post(s)
Liked 2,969 Times
in
1,798 Posts
Likes For smd4:
