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  • 08/07/2025
Road bike wheels can be inflated using a number of different methods. Butyl inner tubes, TPU inner tubes and tubeless sealant are the most popular ways of doing so, but which is best? What is the best way to inflate road bike tyres?
Sam Gupta has tested all three methods to work out what's best. Each has benefits and drawbacks, so Sam identifies what they are and what the best use cases are for each different type of inflation.

This video was produced in partnership with Pirelli / Extra UK
Transcript
00:00There are multiple ways to inflate your road bike tires. Some of the most popular ways include the
00:05standard trusty butyl inner tube, TPU smart tubes, and of course, tubeless. But out of these three
00:12different ways, what actually is the fastest setup? Well, to find out, we've come here to the
00:18Silverstone Sports Engineering Testing Facility, where we're going to be using its rolling
00:23resistance rig. Then we can find out out of the three, which really is the fastest out on the
00:29road. Now, before we start any testing, we have to set some baseline parameters to ensure
00:40that all of the testing is fair. We'll be using the Pirelli P-Zero Race TLR tires with the new
00:47updated Speedcore casing for the tubeless test and the Pirelli P-Zero Race tires for both of
00:53the clincher setups, all of which will be in a 28c tire size. These tires sit at the top of Pirelli's
01:01road race offering and work as the perfect testbed for today. The tires are made in the brand's
01:07Italian factory over in Milan and make use of the most up-to-date technologies, meaning they're
01:13perfect for anyone who wants to go fast without compromise. In fact, the latest TLR version features
01:20Pirelli's new Speedcore casing and it's claimed that this new technology has resulted in a 24% reduction
01:27in rolling resistance, so we should be in for some fascinating results. And to keep everything as
01:34fair as possible, I'll also be using Pirelli's own inner tubes, smart tubes and sealant. The tires
01:41have been mounted to the same fast-forward front wheels, all of which have been pre-set up and have
01:46had over 48 hours sat in the testing facility to ensure that they are fully acclimatized to that
01:53environment. I'll be using this digital Topeak pressure gauge and Joe Blow floor pump to ensure that the
01:59pressures are all exactly the same, which for this test will be six bar. Then, when the tires are on the
02:07rig, each tire will be run on a 10-minute warm-up cycle. Then, we'll run them at two speeds, 25 kilometers per
02:14hour and 40 kilometers per hour, each three times, which will give us some very accurate numbers to
02:21work off. We'll be monitoring the sidewall temperature, the environment temperature and, of course,
02:26those all-important wattage numbers. So, without further ado, let's get going.
02:44So, with the testing concluded, we now have some pretty interesting numbers to have a look at. We'll
02:57first start with the standard Butyl inner tube. Of course, it still very much has its place in the market
03:03and poses a convenient and cost-effective way of setting up your road wheels. The scores on the doors
03:09are as follows. At 24 kilometers per hour, it created 12.8 watts of rolling resistance. However,
03:18at 40 kilometers per hour, it created 24 watts of resistance. So, now that we have the first set of
03:25numbers, let's move on to those Pirelli smart tubes. It created 11.38 watts of resistance at 24 kilometers
03:35per hour and 21.2 watts at 40 kilometers per hour. So, we have already seen a drop in resistance to the
03:44tune of nearly 3 watts. And that's just on one wheel. On to the tubular setup, which makes use of those
03:51P0 race TLR tires. And at 24 kilometers per hour, it created 11.2 watts of resistance. And at 40 kilometers
04:01per hour, it created 20.88 watts. So, compared to the standard inner tubes, the tubeless tires have saved
04:09well over 3 watts per wheel. And compared to the Pirelli smart tubes, it has saved a third of a watt
04:16at 40 kilometers per hour. I think these numbers paint quite an interesting picture. It shows that
04:22the standard inner tubes, although slower, still have a place in the market. But if you really do want to go
04:29fast, the P0 race TLR tires are the way to go. However, if you want to enjoy a clincher setup,
04:36then by using the Pirelli smart tubes, you can increase the performance of the Pirelli P0 race
04:41tire to almost match that of the tubeless version. It's not just rolling resistance that makes you
04:48fast, but instead what the tires feel like when you're out on the tarmac. Reducing feedback through
04:55the bike means that as a rider, you'll be less fatigued and be able to put out more power for
05:01longer. And in my experience, this is where tubeless makes a dramatic difference. The ability to run a
05:08lower pressure means you can achieve just that. Also, the measured widths of the tires actually varied
05:15quite a lot. Despite all the tires being 28C in size, the setups with the inner tubes and smart tubes
05:22measured at 27.7 millimeters across the wheel, while the tubeless setup came in at 28.4 millimeters.
05:29So for the least amount of rolling resistance, we were able to enjoy the largest contact patch with
05:35the road. A bigger contact patch results in more grip and comfort, and that is especially important
05:42when you want to increase your speed in the corners or just over some rough terrain.
05:47Another factor to consider is the weight. A standard butyl inner tube generally comes in at around 100
05:55grams. However, the Pirelli smart tubes, they come in at about 35 grams. And it's a similar story with
06:02the sealant too, because for the 40 milliliters that you get in one of those little bottles,
06:07that comes in at about 45 grams. By reducing the weight of the wheels, especially right at the rim,
06:15you'll be able to take advantage of a faster accelerating wheel, making it easier to attack
06:20on the climbs and just beat your mates in the sprints. But this leads me on to another consideration
06:26that you should be thinking about, and that's puncture protection. Happily, these P-Zero race tires
06:34are equipped with Pirelli's Speedcore technology, meaning that the tires aren't just fast rolling,
06:40but they also contain some puncture protection. However, by opting for the TLR tires, if you do
06:46get a puncture, then the sealant will be able to take care of it, meaning that you can keep on riding.
06:53Whereas on the tube setup, you may have to stop to make a repair.
06:57So what can we take away from all of this information? Well, smart tubes make a lot of
07:05sense for those wanting a lightweight setup and one which is almost as fast as a tubeless one.
07:12But if you're looking to go as fast as possible everywhere, from the results,
07:17the P-Zero race TLR tires certainly steal the crown. They're the fastest rolling, they have the
07:22biggest contact patch with the road, aiding in grip and comfort, and in the event that you do get a
07:28puncture, well, you should be able to keep on riding. They certainly represent themselves as a
07:34high-quality option. Quite frankly, if they are good enough for Trek-Segafrido's Mads Pedersen,
07:39then I've no doubt that they will perform for you too. Happily, these tires sit within Pirelli's wider
07:46range of road tires. So, if you're after other performance tires manufactured in Pirelli's
07:52purpose-built factory in Italy, where the highest standards of quality control and technical
07:57capability are harnessed, covering a multitude of different price points and offering different
08:03features for different conditions, then just head to the link below to discover what could be right
08:08for you. Let me know down below, given the results, which setup would you opt for? If you enjoyed the
08:15video, then please do drop it a like, subscribe to the channel for more content and I will see you again very soon.
08:22I'll see you all.

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