Tubeless vs TPU Tubes vs Butyl: Pirelli Road Tire Setups Compared

Introduction

There are three common ways to inflate a road bike tire: a standard butyl inner tube, a lightweight TPU tube such as the Pirelli Smart Tubes, and a tubeless setup. All three still have a place, but they do not perform the same, and the differences show up most clearly in rolling resistance. To find out which setup is genuinely fastest, three configurations were measured on a rolling resistance rig at the Silverstone Sports Engineering testing facility.

The headline result is easy to state. The tubeless Pirelli P0 Race TLR was the quickest of the three, the Pirelli Smart Tubes brought a clincher setup very close to it, and a standard butyl inner tube trailed both. The detail behind those numbers is what makes the choice interesting, because rolling resistance is only one part of how a tire setup feels and performs on real roads.

How the Setups Were Tested

Every run used the same fast forward front wheels, mounted and left in the testing facility for over 48 hours so the tires could acclimatise fully to the environment. Pressure was set to exactly six bar using a digital pressure gauge and a Joe Blow floor pump. Each tire went through a 10 minute warm-up cycle on the rig before measurement, and each setup was then run at 25 km/h and 40 km/h three times, with sidewall temperature and ambient temperature monitored throughout.

The tubeless test used the Pirelli P0 Race TLR with the updated SpeedCore casing. Both clincher setups used the Pirelli P0 Race, one with standard butyl inner tubes and one with Pirelli Smart Tubes. Every tire was a 28c, and all of them came from Pirelli’s factory in Milan. Holding wheel, pressure, tire size and environment constant matters here, because the gaps between these setups are measured in fractions of a watt and small inconsistencies would hide them.

Pirelli P0 Race TLR: Fastest Rolling Setup

The tubeless setup produced the lowest resistance of the three. At 40 km/h it measured 20.88 watts per wheel, and at the lower test speed it measured 11.2 watts. Compared with a standard butyl inner tube, that is a saving of well over 3 watts per wheel at 40 km/h, and compared with the Pirelli Smart Tubes it is still around a third of a watt ahead.

The latest TLR version carries Pirelli’s new SpeedCore casing, which the brand claims lowers rolling resistance, and the casing also incorporates puncture protection. Running tubeless additionally allows lower pressures, which reduces the amount of feedback reaching the rider through the bike and helps limit fatigue over a long ride. If a puncture does occur, the sealant is designed to close it so the ride can continue.

The P0 Race TLR sits at the top of Pirelli’s road race range, and the same tire family is ridden at the highest level of the sport, including by Mads Pedersen. For riders chasing the lowest possible rolling resistance from a road setup, it is the benchmark of this test.

Pirelli P0 Race: The Clincher Tire

The P0 Race is the clincher tire used for both tube-based setups, and its results show how much the tube choice matters. With a standard butyl inner tube it produced 12.8 watts at the lower test speed and 24 watts at 40 km/h, the slowest combination measured. Switching to Pirelli Smart Tubes dropped those figures to 11.38 watts and 21.2 watts, a reduction of nearly 3 watts.

The tire itself uses Pirelli’s SpeedCore technology, so it is not simply a fast casing with no thought given to durability. Both tube-based setups measured 27.7 mm across the wheel. Butyl inner tubes remain a convenient and cost-effective way to get a road wheel rolling, and the P0 Race is a natural match for riders who want clincher simplicity without stepping down from race-level construction.

Pirelli Smart Tubes: Lightweight TPU Inner Tubes

Smart Tubes are the middle path between a traditional tube and a tubeless setup. They are TPU tubes weighing roughly 35 grams each, against around 100 grams for a typical butyl inner tube, and at 40 km/h they cut rolling resistance by nearly 3 watts compared with butyl. At that speed they came within about a third of a watt of the tubeless setup.

Reducing weight at the rim helps a wheel accelerate faster, which is felt most clearly when attacking a climb or winding up for a sprint. A tubeless setup carries sealant of its own, with 40 millilitres weighing about 45 grams, so a Smart Tubes setup keeps the overall wheel lighter. The trade-off is puncture repair: a tubeless puncture is usually handled by sealant, while a tube setup may mean stopping to make a repair.

For riders who prefer clincher convenience but want performance close to tubeless, the Smart Tubes are the change that delivers the most for the least disruption.

Contact Patch, Grip and Comfort

Rolling resistance is not the only thing that makes a rider fast. Measured width varied noticeably despite every tire being labelled 28c. The butyl and Smart Tubes setups both measured 27.7 mm across the wheel, while the tubeless setup measured 28.4 mm. The fastest setup therefore also put down the largest contact patch on the road, and a bigger contact patch translates into more grip and more comfort.

That matters when you carry speed through a corner or ride over rough surfaces, where a wider, softer footprint keeps the bike settled and the rider fresher. The ability to run lower pressure in a tubeless setup feeds directly into the same effect, reducing the vibration passed back through the frame and letting a rider hold power for longer. Weight matters too, and dropping from around 100 grams to roughly 35 grams at the rim is a meaningful reduction in rotating mass, which is where acceleration gains are easiest to feel.

Buying Advice: Tubeless, TPU or Butyl

The test gives a clear order on pure rolling resistance. The P0 Race TLR tubeless setup is fastest, the P0 Race with Smart Tubes comes very close, and a standard butyl inner tube sits behind both. Those gaps are small in absolute terms, but they are measured per wheel, so they accumulate across a full bike and over a long ride.

Choose tubeless if your priority is the lowest rolling resistance, the widest contact patch, usable lower pressures and sealant-based puncture protection. Choose the P0 Race with Pirelli Smart Tubes if you prefer to stay with a clincher, want most of the performance of tubeless and value a setup that is easy to live with. A standard butyl inner tube still earns its place as a convenient, cost-effective option, particularly for riders who want straightforward roadside repairs.

It is also worth weighing how each setup behaves on real tarmac rather than on a rig. Reduced feedback through the bike means less fatigue, and less fatigue means more power available late in a ride. Pirelli builds its road tires in its own factory in Italy across a range of price points and conditions, so riders who want a different balance of speed, durability and cost have options beyond the three tested here.

Conclusion

On the evidence of this test, the Pirelli P0 Race TLR is the fastest way to inflate a road tire, combining the lowest rolling resistance with the largest contact patch and sealant-based puncture protection. The Pirelli Smart Tubes are the smart upgrade for clincher riders, closing almost the entire gap to tubeless while cutting around 65 grams per wheel against butyl. Standard butyl inner tubes remain the simple, affordable fallback, and they still work well. The right answer depends on whether you value outright speed, low weight, or easy roadside repairs most.