For the average rider, inner tubes have been one of the most enduring and unchanging parts of bicycle design over the decades. They’re made of rubber, they have a Schrader or Presta valve, and they generally do an okay job at cushioning the ride.
However, if you’re an above-average rider, or just obsessive about your gear, you might consider butyl rubber tubes rather old hat. Today, there are far fancier—and more expensive—options on the market if you’re looking to squeeze every drip of performance out of your bike.
A Series Of Tubes
Butyl rubber inner tubes have a lot of things going for them, which is why they’ve been the standard forever. Rubber holds air well, and is easy enough to repair in the event of a puncture. It’s also cheap. However, there are some ways in which the butyl inner tube holds a bicycle back. A thick rubber tube isn’t exactly light; even in a road bicycle application, a single tube can weigh 100 grams or more. They also add to the rolling resistance of a wheel and tire combination. In these regards, other materials have the potential to offer greater performance.
Latex
Latex is a material with many familiar uses, but it’s also recently become a popular alternative material for making inner tubes. It has the benefit of being very light, with a typical road bike latex tube saving 50 grams or more compared to the butyl rubber equivalent. The more flexible material also reduces rolling resistance by several watts at higher speeds, something which can make a real difference under competitive racing conditions. In a more qualitative sense, many riders also prefer the feel of riding on lighter latex tubes.
However, latex tubes also come with drawbacks. The ultra-thin, lightweight material can be susceptive to sudden failure from excessive heat, which can risk a crash in the worst cases. For this reason, the lightest latex tubes are often recommended for use on disc brake bikes only, due to the high temperatures that can be generated by rim brakes on a long descent. Latex tubes also lose air relatively quickly, and thus it’s recommended to pump up latex tubes to the required pressure ahead of every ride. They’re also difficult, but not impossible, to patch, and require some care to avoid damaging their thin walls during installation.
TPU
You might be familiar with thermoplastic polyurethane (TPU) for its use as a flexible 3D printing filament. As it turns out, it’s also a viable material for producing bicycle inner tubes. TPU tubes shave off weight and rolling resistance compared to butyl rubber, albeit not quite as much as the finest latex tubes out there. They do, however, hold air a lot better than latex, reducing the need to reset tyre pressure before each ride. Ride quality is also generally considered better than rolling on traditional butyl rubber tubes. TPU tubes also fold up incredibly small—a largely meaningless benefit in use, but really helpful if you’re trying to pack a spare or three to take on a ride.
Unfortunately, TPU tubes can be quite expensive to procure—often double the price of latex and three or four times that of a butyl rubber tube. The thinnest versions can similarly be at risk of heat failures when used with rim brakes, so it’s important to check before installation if your TPU tubes are rated for use with disc brakes only. Puncture repair can also be difficult, though there are some specialist patches on the market if you wish to attempt it.
Roll, Roll, Roll
It’s worth noting that there is another way to go, as well. It’s possible to buy wheel and tire setups that eliminate inner tubes entirely. These “tubeless” systems offer a major weight reduction, and tend to have lower rolling resistance than even the lightest, most flexible tube setups out there. They’re not really a development of tube technology, but moreso a divergence in wheel and tyre design. In any case, they are pricy, and can require some special equipment to install and maintain. To allow them to self-heal in the event of minor punctures, they’re also typically filled with sealant. In the event of more serious damage, it’s often still possible to install a tube to keep riding, but this is an incredibly messy process that will get sealant all over you.
If you’re a regular commuter cyclist, butyl rubber tubes will probably remain your go-to choice. They’re the cheapest to buy, the easiest to repair, and any benefits from lighter, more efficient tubes are largely wasted on a commute. However, if you’re an avid road cyclist looking for the best feel and efficiency, or especially if you’re getting serious about racing, then you really ought to consider leaving butyl behind for something better. Happy cycling!
I thought cheap bicycle tubes are made of SBR instead of Butyl. SBR has better abrasion resistance so you don’t get a flat so quickly, but it’s more permeable to air so it loses pressure gradually.
As a hacker, the best use of an inner tube for me is sliced, to form elastic bands that do not air-degrade like stationery bands do.
Most butyl tubes still come packed and wrapped by bands made from their QA-failed cousins. Though sometimes you find them wrapped with a bag-tie or even zip-tie, and you wonder at how the company got it so wrong!
The other defecit of TPU (and latex a bit) tubes is that they don’t hold up in storage. I mean “storage” as in a pack or pouch or frame, just waiting around as an “always there if needed” lightweight backup. They fold up nice and compact, but then the corners of the folds all get shredded in the years between a tubeless failure, and when you go to use it, it looks like a child tried to make a ribbon of snowflakes out of it.
I gave up on TPU backups, and just carry extra tubeless plugs and self-stick tire-boots. Lighter than even the lightest TPU tubes, and should still be able to get me home from most places I go. Not to mention (knock wood) that modern tubeless tires are amazingly resislient, especially if you keep the sealant topped up and fresh, so that backups are much less needed than ever before.
Can the sealant freeze?
Yes, but not at any reasonable temperature. Most advertise -20C and some offer low-temperature formulations that go below -30C.
Would have frozen on me. -20 is common in the winter, and -30 happens every few years. That’s why I use gun oil for chains and cables – all the regular bike lubes turn to molasses.
At those temperatures I’d be more concerned about brittle fracture in alumium frame and other parts.
I haven’t heard of anyone’s aluminum bikes failing. Cheap plastics tend to crack – I had my shoes split in half once – but nothing on the bike has gone wrong.
One thing I do notice though, I go through outer tires faster in the winter because the side walls crack easily when the temperature goes down and the pressure in the tire drops. You have to keep them pumped up or it’s one set per winter.
Unlikely. Some are based on ammonia. So I mean yes but not where we’re likely to be riding.
I really like tubeless on my mountain bike but have been very frustrated with tubeless on road bikes, because of the higher air pressure meaning the sealant tends to not seal as well.
Mountain bike, friend rode it through puncture vine, it came back with like 80 punctures, and it still sealed. I got rid of the tire fairly quickly because I just didn’t trust it, but it did work. In contrast, the road bike got maybe two punctures and from then on, every time I went to ride it, it was down to 4 bar, where it’s supposed to be 5.5 or thereabouts. And yes, modern wider aero wheels are built around lower pressure tires, but I don’t have those, I have older narrower rims that expect higher pressure.
Has anyone tried putting sealant in a polyurethane or latex tube? Does it work? Slime in a butyl tube is pretty nice, although if it doesn’t work you can’t really patch the tube.
One thing the article doesn’t mention about tubeless is that you can go with significantly lower air pressure. The high air pressure in a tube setup is required to prevent pinch flats, which are not a problem in tubeless setups. The lower pressure reduces rolling resistance (contrary to common belief) and improves ride quality.
Explain. I notice a markedly higher rolling resistance whenever I let my tires drop in pressure.
This is a contentious topic. If you run wider tires, you can run lower pressure and get the same rolling resistance as a skinny high pressure tire. If you design the wheel/tire system around wider tires, you get a solution that in some situations (notably: road riding on typical messy roads) that wastes less energy overall than skinny high pressure tires.
Leonard Zinn, an ex-racer and bike designer, is usually associated with this idea. Other people started talking about it but he did research on it with an instrumented rolling resistance testbench, published, and popularized the topic.
I can understand that it’s a tradeoff between deforming the tire on impact versus rattling the whole bike up and down, but that’s not a carte blanche to lowering tire pressure because it’s a question of impedance matching. In other words, what configuration causes the bike (and rider) to absorb the least energy from road vibrations, balanced against varying direct rolling resistance caused by the size of the contact patch.
Tyre deformation and contact mechanic is not just “more air = less drag” like any brainlet would think so. Rolling resistance is matched to specific pressure range so if you go higher, you’ll likely end up having a crash.
Turns out that dyno testing on steel rollers doesn’t quite represent the real world.
Spherical cows in vacuums and all that.
Correct. I’ve read that testing the tire against a stiff roller approximately doubles the rolling resistance because the tire deforms twice as much.
From what I understand, tire pressure is only a part of the rolling resistance caused by the tire. There is a difference in “springiness” in the rubbers and plastics used, and this is apparently a big factor. Contracting the tire at the start of the contact patch needs energy, and that is only partly compensated by the expansion at the back end of the contact patch. With an ideal spring there is no difference, but if the tire behaves a bit like putty, then it absorbs a bit of energy while contracting, and it also absorbs energy when the air pressure pushes it back to “round” again.
Improved ride quality maybe.
Better performance due to less mussel fatigue from microshocks is also something that is discussed in bikescene. But noone says the rolling resistance gets lower with lower pressure.
I get mussel fatigue just seeing them on the menu or in the supermarket.
Tyre or tire? Don’t care which, pick one.
Oh, shut up, I’m already tyred.
Inner tubes? What year is it, 1995 😂
On the other hand, it’s amazing how much bicycles have improved in recent years. Tubeless tires, thru axles, UDH, no more front derailleur, hydraulic disk brakes, drop posts, laser-engraved torque specs everywhere. Working on a modern bicycle is such a pleasure compared to the one from something like early 2010s.
For example, I remember replacing worn v-brake pads on my old daily commuter MTB. It was such a pain in the arse to get it all aligned. Then you had to adjust them, braking performance was… good enough I guess.
Nowdays? Just remove the front thru axle (6 mm hex) and put front wheel aside. Then remove cotter pin holding the brake pads, get out old brake pads, insert new pads, secure them with a new cotter pin. Put back front wheel, insert thru axle and torque it to 10 Nm. Done. Maybe 10 minutes of work and your hands are very likely still clean.
Counterpoint: grab tire levers, lever tire off rim, pull tube out, put new tube in, use tire jack to pop tire back on, pump up, vs grab tire levers, lever tire off rim, start cleaning sealant off everything so the new tire will seat right, jam new tire on, pour in sealant, get other side of new tire on, pull valve core to get more airflow in for seating, fire up air compressor, blast air into the tire and hope like mad it seals or otherwise your entire shop is going to be covered in sealant, maybe put a cargo strap around the tire to try to get it to seat better, when it does seat, leave it connected to the air compressor for a while so that it holds the seated shape, make sure the tire stem is at 90 degrees so you don’t have a sealant fountain when you remove the compressor, put the stem core back in, reinflate.
same with getting bubbles out of the hydraulic brake lines vs setting up cable brakes, although those are both a pita, honestly.
Personally, I switched back to cable breaks. Between how often they needed bled and how they could fade on long downhills, I’m happier with the cheaper cable-pull option.
All my tires have tubes and I’ll never run carbon fibre rims– ask André Drege why.
Expense?
ah, but i dont have, nor would i get a torque wrench that can measure something as minute as 10 Nm, nay, i go with my old rim brake bike and tighten enough.
I’ve been wanting to test some TPU tubes with my wheelchair wheels, but the cost is putting me off. Usually just run butyl + slime.
Air?
Nah. I use my bike to commute. I dont have time for a flat if Im using my bike.
Ive run Closed Cell EVA foam inserts for close to a decade now.
I’m using them on my wheelbarrow too! Never got a flat either.
I bought a set on a late night ebay splurge a few days after having had my last flat. I think I spent around $80 for the pair. I honestly thought I was being stupid and would hate them. They may have been one of my best ebay purchases though.
I later bought sets for my daughter and my girlfriend, My daughter is still using hers. My girlfriends lasted longer than our relationship. Ive recommended them to quite a few people I know.
Most balk at the price and ignore my advice. Ive had 3 friends follow through. One guy said they were okay but didnt like the feel of them when trailriding so he switched back to regular tubes. They were the wrong size for our bikes so I didnt take him up on the offer when he asked if I wanted them The other 2 love and swear by them. One of them even hought another set when he replaced his bike after it was stolen.
“A thick rubber tube isn’t exactly light; even in a road bicycle application, a single tube can weigh 100 grams or more”
oh my. add that to the 100kg weight of the rider and you can almost feel it while riding…
but then again, my daily driver is a 1940 transporter bike made by Simplex from Amsterdam. heavy as hell, but uses elongated crancs, so perfect for my long legs. with only 3 speed from a torpedo dreigang I easily manage the very steep dutch hills ;) here in arnhem
If my math is correct, accelerating the 100 gram mass around the wheel would only consume 3-4 Watt-seconds of effort to get up to speed. That’s not very much.
Its all in where the mass is located, the closer to the hub the less inertia produced.
Bought some cheap TPU tubes in roadbike dimensions from Aliexpress and they were both leaking where the valve stem is attached. Avoid!
ok… let’s put that into temporal perspective. I have been running latex inner tubes on my road bike for twenty odd years now. It is the cheapest tuning you can actually do, and there is some anecdotal evidence that they are a bit less prone to punctures – but then I run relatively robust Conti (GP 4000 and now the 5000), and have had only very few punctures in those years. Mostly longish (> 10mm) and thin glass shards or metal strands (blown truck tyres). And a few snake bites due to running too low pressure or hitting a curb full speed.
Tubeless has been pretty much a standard even in semi competitive mountain biking for a decade or more, the higher pressure required for road bikes meant that we are quite a bit behind there, and I personally find it a mess when you have to remove the tyre, and then the stuff dries out and all of the nice weight saving is negated. And it’s a mess. A friend’s son is riding tubeless, but he is a competitive rider.
About the “lower pressure can be faster”: critically depends on the surface roughness. Higher pressure is better only when riding on a track, those are smooth! And this has been discussed for at least twenty years as well, and accepted – look at the modern road bikes, they have really wide tyres and wheels (I’m old and sticking to 23mm, my bike doesn’t accept much more) running lower pressure.
And to the guy above complaining about the stupid cantilever brakes: the cheap ones suck. A lot. I’m totally there with you. I hate them. Avid has the “shorty”, which is a breeze to install and set up, plus just use cartridge brake pads like made by KoolStop. Slip out the old brake pad, slip in the new one, two minutes of work, max. Have those on all bikes using rim brakes.
I disagree that “better tires” are not valuable for “daily commutes”. Pushing more air into tires is the most annoying part of bicycle maintenance for me, (apart from actual flat tires due to leaks).
That we still haven’t managed to replace air as a (leaky) filling…?
Btw, there are various (expensive) attempts at airless tires, but almost no full-latex/styrofoam rings to only replace the tube?
Or bundled up fabric?