Road Bike Tire Basics
When most triathletes think upgrades, they think carbon wheels or power meters or new aero bars, but tires are usually an afterthought. Using the correct tire and tire pressure for the type of riding conditions and course can make your ride faster, smoother, and safer—all without touching your frame!
Tire Size
If someone has ever asked you what size and type of tires you use and you responded with a blank stare, this next part is for you. Road bike tires are simple once you break down the terms. Most modern road bike tires use a size format such as: 700x28c. The 700 refers to the outer diameter in millimeters and the 28c refers to the width of the tire in millimeters.
Common widths for modern road tires are:
• 23 mm — Old school racing standard. Narrow. Very fast. And very harsh.
• 25 mm — The sweet spot for speed and some comfort. Common on many TT/Tri bikes.
• 28 mm — Popular for endurance, mixed surfaces, or heavier riders.
• 30-32 mm — Often used on rough pavement or light gravel.
If you are unsure what your bike can handle, the size of your current tires are printed on the sidewall. For reference, my tri bike uses 700x25c and my road bike uses 700x28c.
Tire Type
There are also different tire types: clinchers, tubeless, and tubular, although we are only going to talk about clincher and tubeless tires in this article because they are the most common on modern road and tri bikes.
Clinchers are the most common. They use an inner tube to inflate; are easy to install, repair, and replace; and are compatible with nearly all road wheels.
Tubeless tires use no inner tube as the name suggests and seals directly to the rim. This allows you to run lower pressure which means more grip and fewer flats (in theory). Tubeless tires need tubeless-ready rimes and tires, plus sealant and a special valve.
I mention that tubeless tires mean fewer flats in theory, but anecdotally I have seen many triathletes at the side of the road having suffered a catastrophic flat on tubeless tires. No matter what type of tire you go with, you need to make sure you know how to maintain your tires and fix a flat quickly. For this reason, I go with clincher tires. Although I have tried tubeless tires multiple times, I am more efficient and quick fixing a flat with a clincher.
The Right Tire for your ride style & terrain
The type of tire you have on your bike can drastically impact your speed on race day. Here are the different types of tires broken into the different riding styles.
The Commuter: Prioritizes puncture resistance, durability, and comfort over speed. Gatorskins are the most common.
The Endurance Rider: Doing bike rallies like Hotter than Hell? Then you want a tire that strikes a balance between comfort, rolling resistance, and durability. The Vittoria Corsa N.EXT is a great option.
The Racer: Every detail matters—weight, rolling resistance, cornering grip, and responsiveness. These are particularly good if you are doing crit style racing or draft legal triathlon. I love the Vittoria Corsa Pro for this type of racing.
The Time Trialer: When every second counts! Lowest rolling resistance and minimum weight. No puncture protection and Tubeless only. The Schwalbe Pro One TT Tubeless.
NOTE: Tires with tan sidewalls are always faster. And when you install your tires make sure the labels on the tires match up with the valve stem.
Picking the right tubes: Butyl vs. TPU vs Latex
The type of tube you put into your clincher tire can impact weight, rolling resistance, speed, and even wheel balance. Standard bicycle inner tubes are made from a synthetic rubber called butyl. TPU and latex inner tubes are made from thermoplastic polyurethane (a type of highly flexible plastic) and latex rubber respectively.
Generally, both TPU and latex are lighter and more flexible than butyl which means lower overall weight and less rolling resistance and a faster ride, but there are specific differences to be aware of. I usually recommend triathletes go with a TPU inner tube if they have high end wheels and tires and here’s why.
Latex inner tubes have very low rolling resistance, are lightweight, and have a really nice ride quality. Latex inner tubes are often more expensive and have poor air retention because latex is a porous substance. The tube can also be easily damaged during installation especially if you are working with a tight tire. And they are also susceptible to damage from heat build up in rims. If you have carbon wheels designed for rim brakes, the heat build up can cause damage to the latex tube.
TPU inner tubes are incredibly light compared to latex and butyl tubes, they have low rolling resistance comparable to latex, and—in the past—have been slightly less efficient than latex inner tubes, but with the savings in weight you most likely come out even. TPU inner tubes are also very compact which makes them easier to install and as excellent options for your flat kit. The one thing going against them is that there are more expensive.
I hope you found this article helpful! Email me at jim.rowe@playtri.com if you have any questions. Happy training and racing this year!
Jim Rowe is a Playtri Level 5 Coach and Coach Education Lead, a USAT LI Certified Coach, an NASM Certified Personal Trainer, and an Ironman and 70.3 World Championship Qualifier who works with adult athletes who are chasing PRs, moving up to long course racing, or want to qualify for a world championship. Learn more about Jim at www.playtri.com/jim-rowe.