TPU Inner Tubes

[foo_fighter]

Has anyone switched their whole fleet to TPU Inner tubes?

Seems like there are some reasonably priced options now.

Other than needing a specific patch and that patching takes 30min, what are the other downsides?

[Ozz]

I think when you inflate them, they stay stretched out so reusing them is difficult. No direct experience with this, but seem to remember someone posting about this.

[pdonk]

They are very fragile during install. Ruined one just by adding a little pressure and it getting caught under bead. Also fragile /easy yo pjnch flat if running less than ideal pressure at the low end.

I'm convinced latex are best.

[Philster]

I’m having good luck so far with the Perrelli version on my all-road bike. I started using them when traveling instead of tubeless and have just stuck with them. Good ride quality and no flats so far. I do think the brand matters.

For reference- 35mm tires, 40psi, 165 pound rider.

[Duvivr6]

I have some el cheapo version I bought on ebay. Installed on carbon wheels, have had no issues for now. They have a few rides probably in for about a month.

[deluz]

My understanding is that they do not provide the same reduction in rolling resistance that latex does. I am sticking with Latex.

[Gwerziou]

I've had no flats in 4 years of commuting to work 10 miles each way on rough roads for all-year round use. I'm running the Tubolito versions, which also hold air without needing to be topped up for an amazingly long time.

[wai2fast]

I'm running Tubolitos on one bike and Pirelli's version on another bike. Zero complaints. They're incredibly light. Rides really well. I would say the ride quality is about the same as latex tubes. Definitely better than butyl tubes. Can go weeks without having to pump them up. I ordered a bunch of RideNow TPU tubes via AliExpress and will throw those on my other bikes when they arrive.

[msl819]

Originally Posted by deluz

My understanding is that they do not provide the same reduction in rolling resistance that latex does. I am sticking with Latex.

What is it about latex that causes the reduction in rolling resistance? I love the latex tubes I have in some of my wheelsets.

[Mark McM]

Originally Posted by msl819

What is it about latex that causes the reduction in rolling resistance? I love the latex tubes I have in some of my wheelsets.

It's an inherent property of the material. Materials have a property called "hysteresis damping", which refers to the amount of energy they return after they are flexed and return to their original shape. The material in a Super Ball has low hysteresis damping, so when they are dropped on a hard surface, they bounce back up almost as high as they were dropped (when it deforms upon hitting the hard surface, it returns almost all the energy of deformation when it rebounds back to its original shape). A Nerf Ball has high hysteresis, and doesn't bounce very high at all (most of the energy of deformation is not returned when it rebounds back to its original shape).

It happens that natural latex rubber has lower hysteresis damping than other other materials used for inner tubes. If you were to make a ball out of solid latex, it would bounce higher than a ball made out of butyl rubber. And when a latex tube flexes as the tire flattens out as it rotates to the bottom of a rolling wheel, more of the energy of that deflection is returned when the latex tube returns to its original shape as the tire rotates away from the bottom of the wheel.

(Hysteresis damping is the primary source of rolling losses in tires on smooth surfaces, i.e road tires, most of it coming from the the hysteresis damping of the tread rubber. Some tire manufacturers have developed special low hysteresis tread rubbers to reduce rolling resistance, such as Continental's Black Chile compound and Vittoria's Graphene tread compound.)

[jimoots]

Love a bit of paceline old man yells at cloud!

I have been running TPU tubes on race wheels (that I often train on in decent weather). Looking at Strava, I've done 15,000km on my race bike (which always has TPU tubes) over the last 18 months. There is probably a bit more as sometimes I put race wheels on my non-race bike.

I've used Tubolitos and now using Schwalbe Aerothans.

Key points:

- They are much lighter. The sort of weight savings you pay thousands of dollars for fancy wheels to achieve.
- They tend to be pretty robust in terms of puncture protection.
- The 'first gen' TPU tubes were faster than butyl but slower than latex; the latest iterations (Aerothans) are as fast as latex but much lighter than butyl and latex.
- They hold air a lot longer than butyl (and much, much longer than latex).
- They do take the shape of the wheel they've been in, so you couldn't take a tube from a wheel and stick it in another wheel that had a narrower tyre. No issue reusing a tube in the same or bigger wheel/tyre combo (i.e. after putting a new tyre in).
- Installation is not any harder/easier than butyl, and easier than latex (i.e. no issues with contamination).

The only draw back that I have found with TPU tubes is that when I run them on 23/25mm tyres, pinch flats tend to happen more often. Like big potholes that might be borderline with a butyl tube will always get a TPU tube, especially so if you have been a bit lazy pumping them up. If you ride seriously bad roads I wouldn't advise a TPU tube (at least in a narrow rim).

To put that in perspective I've probably had 3-4 flats in 15,000km from pinch flats - probably 4 times as many as I'd have with butyl, but on the other hand, I've had 0 other flats with TPU tubes (where I might expect 2-3 on a butyl tube in as many km).

The big, big upside is you can use a TPU tube in a rim braked carbon clincher rim whereas latex is not considered safe to do so.

I don't see any downside against using in preference of latex aside from price. But as noted, that price is narrowing. I can get Aerothans from europe for A$25, whereas Vittoria latex are A$15. Previously TPU tubes were A$40-50.

[sheepbleat]

Jury’s out for me, but here’s some more anecdata for you.

Last year I decided to switch to Tubolito tubes in an effort to save weight. I was riding butyl tubes and typically averaged 1-2 punctures per year. My road riding was consisting of park laps in NYC on weekdays, and longer rides (70-130 miles) outside of the city on weekends.

One of my first Tubolito tubes arrived defective. The tube was somehow stuck to itself on the inside in a way that prevented air from flowing through the valve into the tube. I emailed Tubolito and they quickly replied and sent me a replacement free of charge.

No issues with installation, and there was no discernible difference in ride quality with 25 mm Continental GP5000 tires.

On my second ride I punctured them both.

I replaced them with butyl tubes and carried the punctured Tubolito tubes home in a jersey pocket with the intent to patch them. As others have mentioned, they don’t shrink once they’ve been installed, so punctured ones take up a lot of space in your jersey pockets.

Tubolito recommends a specific patch kit, so I ordered it. Before the patch kit arrived I read some reviews that made me believe that patching them was probably not worth the effort.

Now I have two punctured Tubolito tubes and a patch kit in my closet. I spent $80+ on the setup.

It’s tough to measure the durability of tubes and tires as an individual, as so much is left to chance and the data set is too small to draw a meaningful conclusion. Regardless, I switched back to butyl after the affair and eventually transitioned to tubeless.

[foo_fighter]

Quick update:

I ordered a few pairs of the Ridenow tubes @ ~$8 a piece. At that price I figured it was worth a shot.

Summary:
Installation: A bit harder than butyl, wanted to be extra careful not to have any of the tube folded under the bead and also needed to be careful not to pinch the tube with any levers.

They hold air much better than latex, better then ultralight butyl, on-par with regular or thick butyl. Seems to hold air better at the lower pressures( <50 psi).

Patching is both harder and easier. I had a pinhole on one and tried their patch with an old tube of glue that was already open. It didn't hold. Could have been user error as I patched it partially inflated and I noticed the patch kind of bunched up when deflated.
Switched to Gear-Aid Tenacious Repair tape with some alcohol prep. That seems to be holding up. I ordered some TPU patches on Amazon as spares.

Weight: un-arguably lighter than butyl

Space: Definitely smaller than butyl, could probably fit 2 in the space of 1 butyl tube.

Ride Quality: Can't really tell much of a difference if I'm honest.

Puncture Protection: Haven't had any on road punctures yet. (Knock on wood)

[recarcar]

I had a question about these. Can you stick an undersized TPU tube, say a tube designed for up to 32mm and use it on a 38mm tire the way you can with regular tubes? Would they stretch in a similar way or would using an undersized tube be sketchy here? I am debating picking some up as I've grown tired of cleaning up tubeless sealant and the weight/packability of these is appealing. Thanks!

[foo_fighter]

Yes, they stretch to an extent. However, they do not seem to return to their original shape once stretched. There is a fairly wide range on the tubes like 18-28 and 32-47. I'd probably go up to the 32-47 for the 38c.