icemilkcoffee 

Which TPU tubes is this? The supposed puncture resistance of TPU tubes has been way-oversold. In my experience it is about same as butyl tubes. No better and no worse.
BTW, old ads for tubular tires also claimed that tubulars with latex tubes were 'puncture proof':

https://bulgier.net/pics/bike/Catalo...to-76/p01.html

jonathanf2

TPU tubes shine best on a carbon wheel with at least 21mm internal width (less likely to get pinched in the rim). If there are spoke holes it needs to be taped up like a tubeless setup preferably double wrapped if using narrow high pressure tires. Overall I prefer them and I just buy them in batches. I find the best combination is using a tire that has some degree of puncture resistance. I usually just buy them at $3-4 a pair and have a whole drawer full of them. Also use an electric e-pump to air them up. I can easily carry 2 tpu tubes with barely any weight penalty.

smd4

Being plastic...I wonder if any TPU punctures could simply be "melted" closed with a soldering iron or something similar?

chaadster

Tubolito X Tubo City/Tour is the impossible to puncture TPU with a 1 year warranty on all flats.

WIth regard to your assessment that TPU’s puncture resistance is oversold, I think it’s more the case that TPU’s puncture resistance is misunderstood, as there is virtually no practical way for anyone to assess how many saves (i.e. might have been flats) a TPU provides compared to butyl. We just can’t run both tires in identical situations, so the only insight people have is when they get flats. And it’s just flats; no one is logging road debris conditions when they flat, so it’s just a random-assed inflection point that doesn’t say anything at all about relative puncture resistance between material types. What happens, then, in the absence of any other info, whether a tube flats becomes the measure for puncture resistance.

Color me crazy, but I still understand latex to be more puncture reistant than butyl, so I don’t see anything shocking or amiss in the Clement ad: I’m sure their latex tubulars were more puncture resistant than butyl at the time.

Which brings up another point: the tire is the frontline defense against punctures, and it must be understood that anything able to puncture a tire tread can certainly puncture any tube if the intrusion goes in far enough. Again, we have no practical way of knowing how many tread punctures don’t result in flats, so anyone who claims to have “experience” showing that TPU doesn’t perform better than butyl or latex against punctures is just a charlatan. Outside of the tire, every needle type puncture test shows clear advantage to TPU, so there’s at least some rational basis to expect TPU to deliver some in-tire advantage, too.

squirtdad

let me preface my response with noting I am conservative after decades of commuting and having flats in rain, wind, dark and other not optimum conditions

I try to plan to not have to patch any tube in the wild.
This means carrying 2 spare tubes. I also carry patch kit, levers multitool, valve tool, c02 and a pump, and various other crap likes gloves and wipes. If there is any chance of being in the dark I carry a small headlamp....been a lifesaver.
I have had a couple of cases over the ages where I did need to use both spare tubes and then needed to patch also...
Fwiw for tubies I carry sealant and a spare tire and if I am going long distance two spares

Minimalist i am not

back to subject

My experience trying to find the leaks in the tube are what lead me to maintain field repair of TPU will be difficult at best and probably not possible in bad conditions (dark, windy etc) bit of refinement of wording granted
Specific issues I found/experienced

• TPU tubes are so light that is hard handle them and look for a leak and maintain position once you find a leak. Doing this in wind would be a zoo
• I had do the dunk the tube in a filled sink to find the leaks.....I have not had had to do this with butyl tubes in forever, typically not practical in the wild depending on where you are
• Punctures were hard to see even when found

This is my experience, granted limited, and opinion. Not right or wrong per se, but my thinking based on what I have seen so far

I am sharing information as I see it and the logic behind it, people can use it as the see it. I really don't have an axe to grind

I am not the only person who has noted some of these issues...again every one has different experiences (like some people run a specific tire for huge miles not flats and other run same tire have lots of flats)

I am not quite sure, what gets you animated about this subject

enjoy the ride, butly, tpu, tubeless, tubie

cyccommute 

”Impossible” is a very, very high standard. Even with a 1 year warranty, I’d question if they are “impossible” to puncture in all situations. In the land of soft, fuzzy things like Ann Arbor, MI, the tubes are mostly impervious. Come to the southwest and that “impossible” standard is going to be severely tested. I’ve seen people with tubeless that have flatted here in parts of Colorado. Slime (and other sealants) in tubes are questionable when it comes to going up against goatheads.

Perhaps people misunderstand TPU’s puncture resistance but that doesn’t mean that it isn’t oversold. That was my experience upon installation. The tubes were properly installed. The TPU tubes replaced butyl tubes that were showing zero signs of any kind of puncture. The punctures that occurred with the TPU after installation were due to very small debris in the tire that I later found after two punctures. Both were in the same place and upon very, very, very careful inspection were found but they didn’t cause problems with butyl’s thicker wall.

The patches provided by RideNow were also a major failing of their particular brand. Perhaps other stick-on patches would work but how many different products do you expect me to try? I did eventually get a Tubolito patch kit and it does work well enough. However the 30 minute cure time of the adhesive makes the patch kit something that can used in the field. Yes, I carry extra tubes but here in the land of pokey things, it’s very easy to puncture much more than one…or twice…or 10 times.

Different discussion but latex don’t seem to have any better puncture resistance here or further south where there are many more sharp, pokey things than in Ann Arbor.

Yes, the tire is the frontline defense but it is a piss poor one. Although I don’t run tubeless, there is no bicycle tire product that is impervious to the kinds of sharp object you’ll find here in the southwest. There are some that work a little better…Mr Tuffys are better than “thorn proof” in my experience and sealants from tubeless are better than Slime…but nothing is going to work 100% in all locations.

Frankly, I don’t see how thermoplastic polyurethane (TPU) can be more puncture resistant. The material isn’t particularly stretchy nor does it do well with deformation. Instructions on chasing down leaks warn to not over inflate the tube outside of a tire to avoid deformation of the tube. The material isn’t elastic.

jadmt

got a new GP5000 and installed it using a tpu that has about 3000 miles on it. no tools were used just some baby powder (Schwalbe said not necessary with the Aerothans but won't hurt anything). and the last little bit of the bead I used a little soapy water to get the last few inches on. I had about 6 beers before starting and it still only took about 10 minutes at the most.....no worries about pinches as I can see the entire tube is inside the tire. I blow the tube up by mouth so no worry about over inflating as I again I am old drunk....

terrymorse 

A little clarification: TPU is somewhat elastic, but not nearly as elastic as latex or butyl rubber.

TPU elongation at yield (permanent deformation) can go as high as 35%. Butyl rubber elongation at break (doesn't really yield) is 400-800%.

A huge difference.

zandoval 

The only reason I have not tried out TPU is the initial cost. I am not too excited at having to use sealant in my TPU tubes. I wonder if the specs on TPU tubes will be a marketing ploy. Thicker TPU for example. Still, around here, back in the woods, I dont see anyone using TPU. I am seeing a few more Tubeless though.

Still doing the wait and see... Thanks for posting...

icemilkcoffee 

I can confirm the RideNow self-adhesive stick-on patches are complete garbage. 100% failure rate. I also had Pirelli stick-on patches and one patch stayed on permanently. Another two patches lost air overnight- but stayed on well enough to 'get me home'.
When it comes to TPU patching, it's still very much trial and error- I don't think the industry, or us, have nailed down a BKM yet. I certainly haven't. I have 2-3 tubes that need re-patching as we speak. The glue-on patches are very iffy and temperamental.

jonathanf2

Park Tools makes good glueless patches with strong adhesive. The other day I helped another cyclist with a flat patch his butyl tube and it took all but 10 minutes. I'd use a heat gun or blow dryer to really seal the patches for tubes that need fixing.

chaadster

It must be the water, though self-reported cases of mental *********** are predictably low…

EDIT: handicapation?

rsbob 

I have been successfully running these for months - but then they are in GP5Ks which are pretty puncture resistant. And at these prices, when I get a hole that can’t be patched it’s no big deal. Edit: and best of all, they’re bondage free.

squirtdad

Got it, secret is the 6 beers prior to installing

jadmt

that seems like the magic number of beers depending on how difficult the task....I should have noted that being the tube and tire were both made in Germany a German style hefi was consumed so fairly low abv....

cyccommute 

Which is part of my problem with TPU. I don’t mind experiments but I’d rather not have a 10 mile walk home when I do experiments.

“Somewhat” is doing a lot of heavy lifting there. If the material permanently deforms, that’s not elastic. Elasticity is a 2 part process…expansion and contraction. Rubber goes back to the same shape and size after being stretched. TPU doesn’t. There is the warning in the RideNow package about filling the tube outside of a tire because that can result in permanent deformation. That’s also what makes finding flats such a problem because the TPU tube really can’t be overpressured like rubber can be. Instead of streams of bubbles, the bubbles formed are very tiny.

In fact, the elasticity of TPU tubes is low enough that the size of the TPU tube needs to be carefully matched to tire size. I have direct experience with ruining a 25mm TPU tube in a 37mm tire. The tube expanded on the inner edge of the torus towards the spoke holes and burst.

Rick

[QUOTE][chaadster Posted: It must be the water, though self-reported cases of mental *********** are predictably low…

EDIT: handicapation?/QUOTE]

smd4

No it doesn’t. Glass is more elastic than rubber.

Maelochs

I am already stocking up on glass inner tubes.

terrymorse 

Please clarify, because rubber does indeed return to its original length when the tension is removed (as long as it doesn't break, of course).

"Glass is more elastic than rubber" is technically true (elastic modulus = stress/strain), but completely irrelevant.

smd4

Elasticity: the ability of an object or material to resume its normal shape after being stretched or compressed.

Rubber, when stretched, deforms very slightly; it does not return exactly to its original shape or form. Think used rubber bands. Or some of your nasty old underwear.

Take a two-foot long strip of glass, clamp it vertically in a vise, and pull the top edge, bending the strip. Then release. The glass will return exactly to its original position. It is therefore, by definition, more elastic than rubber.

Which is more elastic rubber or glass

terrymorse 

Nonsense. Stretch and release a rubber band, and it will return to its original length.

Rubber does not lose its elasticity (primarily) from being stressed, but from oxidation, reaction with ozone, and UV radiation.

smd4

You can call it nonsense if you wish. Surprised your HS physics teacher never stumped you with this one.

Or actually, maybe he did.

terrymorse 

Got any references to support this claim that deformed rubber does not return to its original shape when the stress is removed?

Because that goes against everything I learned about elastic deformation.

Okay, some searching has brought up the concept of "stress-induced softening", where elastomers can soften (up to maybe 15%) under certain conditions of deformation. So there's a kernel of truth. Still irrelevant to inner tubes.

smd4

Do I have to explain Google to you too?