yaw

I swapped the enormous 85g Pirelli RoadTUBE butyl inner tubes that held me back for so long with a pair of minuscule 35g P Zero SmarTUBE TPU tubes because I am SmarT I mean, come on, that's 200g saved across 2 tubes and 2 spares. That's, like, more than leaving your phone at home! I could already see the average speed climb up just putting these things in.

Out with the old world rubber and those lardy metal valve stems and in with these inflatable pool toys and flimsy lightweight plastic stems.

So with a spirit of experimentation I set out under the strictest test conditions of my daily 20km morning route, with a total reduced new system 'wet' weight of 78.6kg (for full disclosure this includes a single shot morning coffee) and 80 PSI in a 27mm measured GP5000 front and 75 PSI in a 29mm measured rear tyre. And I'm talking proper pressure gauge measurements here!

For those not familiar, ye olde butyl, the heavyweight staple of the dawdling cyclist generally looking for birds in the trees whilst meandering along in unpredictable ways, and the slick latex tube employed by those with the serious riding faces whose little pinkies pick up every crevice in each granule their supple tyres grace, has been joined by TPU (thermoplastic polyurethane) - for quite some time actually - with promises of half the weight and better puncture resistance than equivalent butyl (if by equivalent they mean a similar weight or material thickness, then that would be one fragile butyl tube, mind you). These things haven't quite caught on yet, perhaps owing to the much higher price exacerbated by the difficulty of repair, but some more brands seem to be reviving this material choice. In tests, they appear to slot in right between latex and butyl in terms of rolling resistance and air retention, weight being the primary stand-out argument here. Any weight weenie can attest that the price is totally justified based on dollars per grams saved when compared to those new lightweight hubs they just had laced to their 1kg wheelset.

So with that out of the way, on to the test results: I can't claim to perceive a difference even if you'd pay me in a lifetime supply of plastic to describe the new 'road feel' and 'acceleration boost'. My average speed was slightly up, but then again I think I had two fewer dog leashes than usual stretched across the river bike path on this careful test run.

Now I am curious - who here has gone TPU, what do you have to say about it, and can we get any anecdotes regarding long term reliability?

TiHabanero

Many years ago all the rage was latex tubes. Lighter, stronger, faster, more supple. Tried them as we were set to sell them and found absolutely zero difference in ride quality or performance. None. We did not stock them after that and only ordered when requested by customer.

TMonk

latex tubes are faster than butyl TiHabanero. Plenty of data to support that.

seypat

I think the ribbed latex ones give a more pleasurable ride experience.

surak

I carry one Aerothan tube in my saddle bag. Haven't had to use it yet because I run tubeless. Read that TPU tubes are very tricky to patch. Hope to never find out.

tempocyclist

I'm sure they are. All the testing and data points to them being faster.

I certainly can't perceive any difference swapping between Conti Race butyl tubes and Latex tubes. I still use them in my time trial bike wheels though. Every little helps!

yaw

I heard tubeless feels best

Yeah not only the weight but also the small size when rolled up makes these really good for back ups, even if riding with other configurations.

Camilo

People pay good money to save a hundred grams on a set of wheels! I've always said, if you're into weightweenism (mea culpa, but recovering) the cheapest way to get towards whatever low weight goal you have is to buy lightweight tires and tubes. Aside from weight, the better, lighter tires and tubes often give a better ride.

frogman

tFUnK

I wonder if there's a ceiling effect here in that OP was already using a light butyl tube with a quality clincher tire before switching to the TPU tube.

No experience with TPU tubes personally, but I do notice a smoother ride going from light-medium weight butyl tubes to latex tubes on the same tires (Vittoria open clinchers). I didn't feel faster (confirmed by Strava) but it felt smoother and more comfortable (could be placebo, for sure).

yaw

I experimented quite a bit to arrive at my favourite PSI split for these tyres and in that process heightened my road feel senses simply through paying repeated attention to slight differences. That said, there will no doubt be more experienced and sensitive riders out there that may pick up these material differences, which are objectively significant when comparing both in hand, through the tyre, but I personally cannot despite keeping PSI exactly the same (overinflate a bit then drop to exact pressure with a Topeak air release gauge) on very familiar and varied road surfaces. So to me at least, 5 PSI up or down make a far greater difference in comfort/smoothness/perceived rolling resistance than these two Pirelli tube types.

tFUnK

Yup, I don't doubt that. It could be that the specific butyl tubes you had before were already quite good in quality and performance.

And it seems we should be talking about two independent dimensions here: weight and suppleness. The weight savings is significant (relative % at least) and well documented. The jury may still be out on TPU's suppleness (I gather it may be more supple than butyl but less so than latex?).

yaw

You may be right with that ceiling, but I think the best comparison for most people considering these is precisely between higher end butyl and latex (say 80-90g) and TPU (say 35g). Super light butyl/latex seems too fragile and should in theory be significantly more fragile than TPU based on general material properties, so I'd say this sort of weight comparison is fairest. Heavier butyl is of course outclassed by all of them in a performance oriented discussion. TPU and latex cost around the same where I live, 2-3x more than decent performance butyl, and probably 8-10x more than basic butyl.

So many people with good butyl tubes may then wonder which of these is a viable upgrade at a similar cost.

I think it goes something like this:

• If easy install, patching or re-use is required, stick with performance butyl.
• If you do not want to inflate tyres on a daily basis, avoid latex.
• If rolling resistance is a priority, go latex.
• If road feel is important, go latex.
• If weight is paramount at no performance penalty over butyl, go TPU

So TPU gives us a weight advantage with middle of the road performance at the cost of repairability. Butyl is above all practical at the cost of performance or is too fragile on the lightest end of the spectrum. Latex arguably gives us the best all out performance with some air retention and installation inconvenience. There may be more factors, like how rapidly these three materials lose air in various puncture scenarios, which may have a significant impact on safety and recoverability at speed. On that point it seems that it may be TPU>butyl>latex but that's anecdotal at best, and I've read about both 'shredded' and 'very slow air loss' TPU failures. Too many factors here without detailed isolated tests I think. The material definitely seems less prone to tear up from a pin hole, if so, the safety factor could be very interesting on the scales of truth.

I'd pair up latex with an all out aero bike on the flats and put TPUs in a dedicated lightweight climbing bike. That seems like a natural fit.

tFUnK

Well put. Certainly agree on the finickiness of installing latex tubes. Latex creeps through even the smallest of cuts (the ones that go through the tire, not the surface ones). Heck, I've had latex creep through just aged but otherwise undamaged sidewalls.

HTupolev

If anything, I seem to get fewer flats on latex than on butyl. Latex performs very poorly in plunger puncture tests, but it's not obvious that those tests are representative of how punctures actually happen.

Specifically in the context of patching and re-use, latex is a very strong contender. If you use a piece cut from an old latex tube as a patch, vulcanizing fluid on both surfaces, getting a great bond is effortless.

TiHabanero

No doubt the latex tubes are lighter by a significant amount for a tube, and the data shows they produce a faster wheel, however in our testing on aa 15 mile known time trial course with riders that did the course every week in season, the tubes showed absolutely no advantage. Real world testing done over a 1 month period. Two riders for a total of eight trials. The results were real.

yaw

What weights are you referring to here, the latex I know weighs in the order of 85g, same as the Pirelli RoadTube butyl, both more than double the weight of a 35g TPU tube.

HTupolev

How big of a discrepancy were you looking for, and how much precision did your testing have?

The speed advantage of latex tubes over butyl can be on the order of a couple tenths of a mph. It's very good as a performance-per-dollar change as road bikes go, but still small enough to require at least mildly careful testing to discern.

chaadster

I had no problems patching a Schwalbe Aerothan TPU tube with a Lezyne glueless patch, and still ride that tube now, nearly a year later. I did wipe the puncture area with alcohol before patching, so perhaps that’s a factor.

For me, gong with Aerothan was the ideal solution to the problems I was having running Herse Extralight casing tires, which I could not get to reliably seal tubeless. I was using the Herse recommended SealSmart, but the tires would leak air and sealant through the sidewalls no matter what I did, and that was just too much of a hassle to go on.

Aerothan promised the best performance, ease-of-use, and durability solution, and I was not disappointed. I run three tubeless bikes (down from five), two with Aerothan, and five with butyl, so I’m pretty attuned to the feel of a variety of tires and tubes, and I’ve run latex in the past, about 16 years ago, but they proved to fussy, fragile, and expensive to stick with.

If I didn’t have a fleet to look after, I’d probably just run tubeless and keep TPU in the emergency road repair kit to save weight and space, but with 15 bikes (including the wife’s and kids’) to keep up on, I have no time for futzing around highly prize stuff which works fuss-free, so Aerothan have been awesome in providing that without having to sacrifice much, if anything, in performance, feel, or security.

PeteHski

I've been thinking about buying a Tubolito as an emergency back-up spare (I run tubeless) simply because they are lighter and less bulky than butyl tubes. Relatively expensive though for something I will probably never use!

GhostRider62

How did you control for temperature? Tire pressure? Barometric pressure?

Your test is not valid, that is for real.

rm -rf

My first reaction is that "a couple of tenths" was too high. But on this bike speed calculator, taking defaults, but in the drops, 250 watts=23.2 mph, 260 watts=23.5. 0.3 mph faster if the rider saves 5 w per wheel. More than I guessed. I'm thinking that latex vs lightweight butyl is 3-5 watts savings.

Over 25 miles distance, 20 mph vs 20.1 mph is 22 seconds. Hard to notice in real life, a big deal in a race.

rm -rf

They roll up very small, I think. I have a Michelin ultra light butyl, folded into a long oval that's the length of my small saddle bag, so it packs efficiently.

Saddle bag wear
I've seen two saddle bag spares that went flat soon after replacing a punctured tire. They had been in the saddle bag for many months or years, and the folded edge got enough wear to make it a weak point. The hole was like a snakebite slit, but all rough and abraded along the edge of the slit.

I wrap my spare in a piece of Tyvek from an old overnight envelope to protect it. (It's been in there a couple of years now.)

GhostRider62

Latex gets you a couple watts per tire. And maybe 5 seconds on a TT. Could be the difference from Podium to top 10 but not something that can be measured comparing times week to week. The quickest way to compare would be a slow rolldown test performed multiple times on the same day in calm conditions and only change the tubes, all else identical. The latex tubes will rollout further every single time. To quantify in Crr takes more effort but it can be done, too.

himespau 

The problem is, if you have to pump them up more frequently, you'll slowly lose those "cyclist's arms" for something with more bulk and you'll just be transferring that weight you saved from your tubes to your upper body. Sure, that's less rotating mass, but bulkier arms are also less aero, so there's a trade-off there.