A number of recent trends in cycling have led riders to stray from the conventional wisdom that thin tires are the best option for road bikes. Professionals are moving to wider tires for an increasing number of racing conditions. Hybrid bikes are becoming a popular alternative to road bikes with many hobbyists. You might be wondering if going bigger is right for your ride.
Can you put thicker tires on a road bike? There are several factors that limit how thick of a tire you can put on your road bike. These vary by model and by the age of your bike. If your bike’s frame, brakes, and stays offer enough clearance to permit it, going thicker will give you more comfort and control without costing speed or efficiency.
Thinner tires are faster and faster is better, right? For decades this was accepted as one of the most fundamental facts of bicycle racing. But in recent years, the “thinner is faster” rule has been discredited. As a result, more cyclists are experimenting with thicker tires. Read on to learn what you need to know if you’re thinking of giving thicker tires a try.
Why Put Thicker Tires on a Road Bike?
For a long time, the best science and engineering available to professional bicycle racing pointed in the direction of thinner tires. They offered better aerodynamics and reduced rolling resistance to shave valuable seconds off of your time. The increased speed was worth the price paid in comfort, handling, and rim pinched flats if you wanted to win – or so we were told.
More recent studies have revealed that when you account for how tires distribute weight when they’re under a load, thicker tires turn out to be faster. Many leading manufacturers and athletes now subscribe to the idea that “smoother is faster.” The best thinking about speed and performance now considers how bike and rider work together for extended periods.
Even if fractions of a second were as important to the average rider as they are to professional racers, there would be no downside to going with thicker tires when it comes to speed. But are there any upsides to thicker tires that make it worth your while to make the switch?
Thicker tires allow you to run lower tire pressures without risking the headache of a rim pinch. Lower pressure means that your tires will absorb more of the shocks from the road or trail and provide you with a more comfortable ride. At the same time, they give you more surface area in contact with the road, so you get better handling and control.
What Factors Determine How Thick You Can Go?
Now that word is out about thicker tires, manufacturers are designing new bikes with frames and braking systems that will accommodate tires much thicker than the 23mm that was a standard for so many years. But if you’re looking to take advantage of thicker tires on the bike you have, you’ll have to consider the clearance that your frame, brakes, and stays offer.
The amount of space that you have between the front forks is generally more accommodating than what you’ll find in the rear forks. This is due to the rear fork being a more crowded area of the bike. Additional elements of the frame like seat tube clearance and down tube clearance come into play in determining the clearance of the rear forks.
This is unfortunate because it can work well to run a thicker tire in the rear of the bike than in the front. The reverse delivers less than stellar results for a number of reasons. As a result, the thickness that your rear fork will allow is one of the primary factors in determining whether you can go bigger and how big you can go.
There are a number of different braking systems that have been tried out by performance bicycle manufacturers over the years. Some have stood the test of time and gotten better through many rounds of improvements and upgrades. Others have burst onto the scene only to fade away almost as quickly as they appeared.
One of the reasons that disc brake systems are becoming more popular in the design of new road bikes is the extra room they provide for thicker tires. Yet many quality bikes still feature caliper brakes.
If your bike features a caliper brake system, you will need to determine whether the calipers are standard (39-49mm), long (47-57mm), or extra-long (57-73mm). The size of your calipers might limit your options for thicker tires even more than the frame’s clearance.
Both the stay width and the stay bridge clearance are additional elements that you’ll have to consider in the already crowded area around the rear forks of your bike. Depending on the specifics of your bicycle’s frame and other components, you may be able to adjust these to get a bit more clearance.
The final factor that you’ll have to take into consideration if you want to go with thicker tires is the limits of what your wheels will tolerate. 700c wheels might get you from 23mm to 25mm, but you’ll be pushing it when you go much thicker than that.
NOTE: Of course, it’s possible to change all of these components on your bicycle – with the exception of the frame. Doing so will allow you to run the thickest tires that your frame will allow. At some point, though, it will probably become cheaper, easier, or both to just purchase a new bike with an eye toward thicker tires and clearance to spare.
What Are the Benefits of Going Thicker?
As we mentioned earlier, going with thicker tires actually reduces rolling resistance. By going with thicker tires, you’ll not only be going farther and faster for the same amount of effort—you’ll be more comfortable and have more handling control while you are.
The key to overturning the conventional wisdom that “thinner is faster” came when studies began to consider the shape of a tire under a load. With a rider’s weight on the bicycle, all tires flatten. This is known as a tire’s “deflection.”
When inflated to the same pressure, a thin tire and a thick tire will have the same contact area with the road. But a thinner tire will flatten along the line of the wheel and get longer and less round. In comparison, a thicker tire will flatten across the line of the wheel, which results in a shorter flattened area and a rounder shape. That’s why thicker tires roll better – and faster than thinner ones.
It’s probably no surprise that a thicker tire will give you a more comfortable ride. Thinner tires have to be pumped up until they’re hard to guard against pinch flats. Hard tires transfer every bump in the road or trail straight to the frame and on to the rider.
Contrast that with thicker tires and lower pressures where a more cushioned ride is your reward. But you should also consider how much that extra comfort can contribute to your speed and endurance. Bodies perform better when they’re not being battered by every bump in the road.
Thank the mountain bikers for being the first ones to point out that lower tire pressure adds up to improved grip and control. The same is true for road bikes. A thicker tire puts a larger section of rubber in contact with the road. When you lower the tire pressure, the section gets even bigger.
Even when you’re cornering aggressively, lower tire pressure is your friend. At lower pressures, the tire can grip irregularities and variations in the road surface more effectively. That means you can lay the bike into corners with less risk of road rash.
If you want to get the most that your old road bike can offer you in terms of speed, comfort, and handling—thicker tires are the way to go. By taking note of what your frame, brakes, stays, and wheels will allow, you can upgrade to the thickest tires possible. If you’re pleased with the results and want to go even thicker than your old bike will allow there are a lot of good options for you to consider.